geotechnical properties of oil contaminated soil
Post on 05-Oct-2021
4 Views
Preview:
TRANSCRIPT
1
`
GEOTECHNICAL PROPERTIES OF OIL CONTAMINATED SOIL
A thesis submitted to The University of Manchester for the degree of
Master of Philosophy
in the Faculty of Engineering and Physical Sciences
2015
Miebaka Ransome Daka
School of Mechanical, Aerospace and Civil Engineering
2
CONTENTS CONTENTS 2
LIST OF ABBREVIATIONS 24
LIST OF SYMBOLS 25
ABSTRACT 28
DEDICATION 29
DECLARATION 30
COPYRIGHT STATEMENT 31
ACKNOWLEDGEMENT 32
CHAPTER 1 INTRODUCTION 33
1.1 Background 33
1.2 Problem statement 33
1.3 Aim and objectives 35
1.4 Scope of the study 36
1.5 Limitations of the study 37
1.6 Structure of the thesis 38
CHAPTER 2 LITERATURE REVIEW 39
2.1 Geotechnical properties of oil contaminated soils 39
2.1.1 Aggregate size distribution of oil contaminated soils 40
2.1.1.1 Summary on aggregate size distribution of oil contaminated soils 41
2.1.2 Atterberg limits of oil contaminated soils 41
2.1.2.1 Oil contamination increases the Atterberg limits 41
2.1.2.2 Oil contamination decreases Atterberg limits 42
2.1.2.3 Summary on Atterberg limits of oil contaminated soils 46
3
2.1.3 Compaction of oil contaminated soils 47
2.1.3.1 Oil contamination, increase in maximum dry density and
decrease in optimum water content 47
2.1.3.2 Oil contamination, decrease in maximum dry density and
decrease in optimum water content 49
2.1.3.3 Summary on compaction of oil contaminated soils 55
2.1.4 Hydraulic conductivity of oil contaminated soils 55
2.1.4.1 Oil contamination decreases hydraulic conductivity 56
2.1.4.2 Summary on hydraulic conductivity of oil contaminated soils 58
2.2 Summary of Literature Review 59
CHAPTER 3 MATERIALS AND EXPERIMENTAL PROCEDURES 60
3.1 Materials 60
3.1.1 Properties of soils, mineralogical content of clays and oil characteristics 60
3.1.1.1 Particle size distribution of bentonite, kaolinite and sand 60
3.1.1.2 Mineralogical content of bentonite and kaolinite 61
3.1.1.3 Characteristics of Shell Tellus oil 68 62
3.1.1.4 Soil mixture ratio and oil content 62
3.2 Significance of tests 64
3.2.1 Grading modulus using aggregate size distribution 64
3.2.2 Atterberg limits 66
3.2.3 Compaction 67
3.2.4 Hydraulic conductivity 68
4
3.3 Specimen preparation 68
3. 3.1 Specimen for the grading modulus tests 68
3.3.2 Specimen for the Atterberg limits tests 69
3.3.3 Specimen for the compaction test 70
3.3.4 Specimen for the hydraulic conductivity test 70
3.4 Equipment for experimental testing 70
3.5 Experimental procedures and typical test result 71
3.5.1 Procedure for the grading modulus test 71
3.5.2 Procedure for the Atterberg limits tests 72
3.5.3 Procedure for the compaction test 75
3.5.4 Procedure for the hydraulic conductivity test 80
3.6 Summary of Chapter 3 83
CHAPTER 4 RESULTS AND DISCUSSION 85
4.1 Aggregate size distribution of contaminated soils 85
4.2 Grading modulus of oil contaminated soils 88
4.3 Plasticity characteristics of oil contaminated soils 90
4.4 Compaction of oil contaminated soils 95
5
4.4.1 Compaction curves using variation of dry density and water content 95
4.4.2 Compaction curves using variation of dry density and total fluid content 101
4.4.3 Compaction curves from variation of dry density and total fluid content
using data of some previous researchers 104
4.5 Plasticity characteristics and compaction of oil contaminated soil 109
4.6 Hydraulic conductivity of oil contaminated soil 111
4.7 Plasticity characteristics and hydraulic conductivity of oil contaminated soil 113
4.8 Compaction characteristics and hydraulic conductivity of oil contaminated soil 117
4.9 Summary of results and discussions 119
CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS FOR
FUTURE WORK 120
5.1 Grading modulus of oil contaminated soils 120
5.2 Plasticity characteristics of oil contaminated soils 120
5.3 Compaction of oil contaminated soils 121
5.4 Hydraulic conductivity of oil contaminated soils 121
5.5 Recommendations for future work 122
REFERENCES 123
6
APPENDIX A AGGREGATE SIZE DISTRIBUTION AND
GRADING MODULUS TESTS RESULT 131
A1 Particle size analysis test result of sand 131
A2 Specific gravity of sand 132
A3 Specific gravity of bentonite and kaolinite 133
A3.1 Specific gravity of bentonite 133
A3.2 Specific gravity of kaolinite 134
A4 Hydrometer test 134
A4.1 Calibration parameters 134
A4.2 Hydrometer test formulae 135
A4.3 Calibration correction equations 135
A4.4 Hydrometer test (Bentonite) 137
A4.5 Hydrometer test ( Kaolinite ) 138
A5 Aggregate size distribution test results 139
A5.1 Soil 1 139
A5.2 Soil 2 141
A5.3 Soil 3 144
A5.4 Soil 4 146
A5.5 Soil 5 149
7
A6 Grading modulus 152
A6.1 Soil 1 152
A6.2 Soil 2 152
A6.3 Soil 3 152
A6.4 Soil 4 152
A6.5 Soil 5 153
APPENDIX B ATTERBERG LIMITS TESTS RESULT 154
B1.1 Atterberg limits data for bentonite 154
B1.2 Atterberg limits data for kaolinite 155
B1.3 Atterberg limits data for soil 1 (0.0% oil content) 156
B1.4 Atterberg limits data for soil 1 (1.8% oil content) 157
B1.5 Atterberg limits data for soil 1 (3.5% oil content) 158
B1.6 Atterberg limits data for soil 1 (5.3% oil content) 159
B1.7 Atterberg limits data for soil 1 (7.1% oil content) 160
B1.8 Atterberg limits data for soil 2 (0.0% oil content) 161
B1.9 Atterberg limits data for soil 2 (1.8% oil content) 162
B1.10 Atterberg limits data for soil 2 (3.5% oil content) 163
B1.11 Atterberg limits data for soil 2 (5.3% oil content) 164
8
B1.12 Atterberg limits data for soil 2 (7.1% oil content) 165
B1.13 Atterberg limits data for soil 3 (0.0% oil content) 166
B1.14 Atterberg limits data for soil 3 (1.8% oil content) 167
B1.15 Atterberg limits data for soil 3 (3.5% oil content) 168
B1.16 Atterberg limits data for soil 3 (5.3% oil content) 169
B1.17 Atterberg limits data for soil 3 (7.1% oil content) 170
B1.18 Atterberg limits data for soil 4 (0.0% oil content) 171
B1.19 Atterberg limits data for soil 4 (1.8% oil content) 172
B1.20 Atterberg limits data for soil 4 (3.5% oil content) 173
B1.21 Atterberg limits data for soil 4 (5.3% oil content) 174
B1.22 Atterberg limits data for soil 4 (7.1% oil content) 175
B1.23 Atterberg limits data for soil 5 (0.0% oil content) 176
B1.24 Atterberg limits data for soil 5 (1.8% oil content) 177
B1.25 Atterberg limits data for soil 5 (3.5% oil content) 178
B1.26 Atterberg limits data for soil 5 (5.3% oil content) 179
B1.27 Atterberg limits data for soil 5 (7.1% oil content) 180
B2 Oil loss test 181
APPENDIX C COMPACTION TEST RESULTS 185
9
APPENDIX D PLASTICITY CHARACTERISTICS AND
COMPACTION OF CONTAMINATED SOIL 198
APPENDIX E HYDRAULIC CONDUCTIVITY 200
APPENDIX F PLASTICITY CHARACTERISTICS AND
HYDRAULIC CONDUCTIVITY OF CONTAMINATED
SOIL. 210
APPENDIX G COMPACTION CHARACTERISTICS AND
HYDRAULIC CONDUCTIVITY OF CONTAMINATED
SOIL 212
LIST OF TABLES
Table 2.1: Properties of clay, before and after contamination (Rehman et al, 2007) 41
Table 2.2: Summary on Atterberg limits 47
Table 2.3: Summary of Maximum dry density and optimum water content of soils 55
Table 3.1: Mineralogical content of Wyoming bentonite and China clay kaolinite
(MSDS, 2011; WMA, 2013) 61
Table 3.2: Characteristics of high viscosity Shell Tellus oil 68 (MSDS, 2006) 62
Table 3.3: Soil mixtures with different oil content chosen for the present study 63
Table 3.4: Plastic limit of uncontaminated soil 1 75
Table 3.5: Comparison of known water added to contaminated soil and measured
water content (Zheng et al, 2014) 79
Table 3.6: Quantity of flow, Q interval (ml) in 5 mins for uncontaminated soil 83
Table 4.1: Liquid limit and plastic limit of soil minerals and clay soils of study 91
10
Table 4.2: Summary of study 119
Table A1: Particle size distribution data for sand 131
Table A2: Specific gravity of sand 133
Table A3.1: Data of specific gravity of bentonite 133
Table A3.2: Data of specific gravity of kaolinite 134
Table A4.1: Calibration data for hydrometer 136
Table A4.2: Data of hydrometer test for bentonite 137
Table A4.3: Data of hydrometer test for kaolinite 138
Table A5.1: Aggregate size distribution data for soil 1 (0.0% oil content) 139
Table A5.2: Aggregate size distribution data for soil 1 (1.8% oil content) 139
Table A5.3: Aggregate size distribution data for soil 1 (3.5% oil content) 140
Table A5.4: Aggregate size distribution data for soil 1 (5.3% oil content) 140
Table A5.5: Aggregate size distribution data for soil 1 (7.1% oil content) 141`
Table A5.6: Aggregate size distribution data for soil 2 (0.0% oil content) 141
Table A5.7: Aggregate size distribution data for soil 2 (1.8% oil content) 142
Table A5.8: Aggregate size distribution data for soil 2 (3.5% oil content) 142
Table A5.9: Aggregate size distribution data for soil 2 (5.3% oil content) 143
Table A5.10: Aggregate size distribution data for soil 2 (7.1% oil content) 143
11
Table A5.11: Aggregate size distribution data for soil 3 (0.0% oil content) 144
Table A5.12: Aggregate size distribution data for soil 3 (1.8% oil content) 144
Table A5.13: Aggregate size distribution data for soil 3 (3.5% oil content) 145
Table A5.14: Aggregate size distribution data for soil 3 (5.3% oil content) 145
Table A5.15: Aggregate size distribution data for soil 3 (7.1% oil content) 146
Table A5.16: Aggregate size distribution data for soil 4 (0.0% oil content) 146
Table A5.17: Aggregate size distribution data for soil 4 (1.8% oil content) 147
Table A5.18: Aggregate size distribution data for soil 4 (3.5% oil content) 147
Table A5.19: Aggregate size distribution data for soil 4 (5.3% oil content) 148
Table A5.20: Aggregate size distribution data for soil 4 (7.1% oil content) 148
Table A5.21: Aggregate size distribution data for soil 5 (0.0% oil content) 149
Table A5.22 Aggregate size distribution data for soil 5 (1.8% oil content) 149
Table A5.23: Aggregate size distribution data for soil 5 (3.5% oil content) 150
Table A5.24: Aggregate size distribution data for soil 5 (5.3% oil content) 150
Table A5.25: Aggregate size distribution data for soil 5 (7.1% oil content) 151
Table A6.1: Percentage of mass of soil retained on sieves for soil 1 152
Table A6.2: Percentage of mass of soil retained on sieves for soil 2 152
Table A6.3: Percentage of mass of soil retained on sieves for soil 3 152
12
Table A6.4: Percentage of mass of soil retained on sieves for soil 4 152
Table A6.5: Percentage of mass of soil retained on sieves for soil 5 153
Table A6.6: Grading modulus of oil contaminated soils 153
Table B1.1: Liquid limit data for bentonite 154
Table B1.2: Plastic limit data for bentonite 154
Table B1.3: Liquid limit data for kaolinite 155
Table B1.4: Plastic limit data for kaolinite 155
Table B1.5: Liquid limit data for soil 1(0.0% oil content) 156
Table B1.6: Plastic limit data for soil (0.0% oil content). 156
Table B1.7: Liquid limit data for soil 1(1.8% oil content) 157
Table B1.8: Plastic limit data for soil (1.8% oil content) 157
Table B1.9: Liquid limit data for soil 1(3.5% oil content) 158
Table B1.10: Plastic limit data for soil (3.5% oil content) 158
Table B1.11: Liquid limit data for soil 1 (5.3% oil content) 159
Table B1.12: Plastic limit data for soil (5.3% oil content) 159
Table B1.13: Liquid limit data for soil 1 (7.1% oil content) 160
Table B1.14: Plastic limit data for soil 1 (7.1% oil content) 160
Table B1.15: Liquid limit data for soil 2 (0.0% oil content) 161
13
Table B1.16: Plastic limit data for soil 2 (0.0% oil content) 161
Table B1.17: Liquid limit data for soil 2 (1.8% oil content) 162
Table B1.18: Plastic limit data for soil 2 (1.8% oil content) 162
Table B1.19: Liquid limit data for soil 2 (3.5% oil content) 163
Table B1.20: Plastic limit data for soil 2 (3.5% oil content) 163
Table B1.21: Liquid limit data for soil 2 (5.3% oil content) 164
Table B1.22: Plastic limit data for soil 2 (5.3% oil content) 164
Table B1.23: Liquid limit data for soil 2 (7.1% oil content) 165
Table B1.24: Plastic limit data for soil 2 (7.1% oil content) 165
Table B1.25: Liquid limit data for soil 3 (0.0% oil content) 166
Table B1.26: Plastic limit data for soil 3 (0.0% oil content) 166
Table B1.27: Liquid limit data for soil 3 (1.8% oil content 167
Table B1.28: Plastic limit data for soil 3 (1.8% oil content) 167
Table B1.29: Liquid limit data for soil 3 (3.5% oil content) 168
Table B1.30: Plastic limit data for soil 3 (3.5% oil content) 168
Table B1.31: Liquid limit data for soil 3 (5.3% oil content) 169
Table B1.32: Plastic limit data for soil 3 (5.3% oil content) 169
Table B1.33: Liquid limit data for soil 3 (7.1% oil content) 170
14
Table B1.34: Plastic limit data for soil 3 (7.1% oil content) 170
Table B1.35: Liquid limit data for soil 4 (0.0% oil content) 171
Table B1.36: Plastic limit data for soil 4 (0.0% oil content) 171
Table B1.37: Liquid limit data for soil 4 (1.8% oil content) 172
Table B1.38: Plastic limit data for soil 4 (1.8% oil content) 172
Table B1.39: Liquid limit data for soil 4 (3.5% oil content) 173
Table B1.40: Plastic limit data for soil 4 (3.5% oil content) 173
Table B1.41: Liquid limit data for soil 4 (5.3% oil content) 174
Table B1.42: Plastic limit data for soil 4 (5.3% oil content) 174
Table B1.43: Liquid limit data for soil 4 (7.1% oil content) 175
Table B1.44: Plastic limit data for soil 4 (7.1% oil content) 175
Table B1.45: Liquid limit data for soil 5 (0.0% oil content 176
Table B1.46: Plastic limit data for soil 5 (0.0% oil content) 176
Table B1.47: Liquid limit data for soil 5 (1.8% oil content) 177
Table B1.48: Plastic limit data for soil 5 (1.8% oil content) 177
Table B1.49: Liquid limit data for soil 5 (3.5% oil content) 178
Table B1.50: Plastic limit data for soil 5 (3.5% oil content) 178
Table B1.51: Liquid limit data for soil 5 (5.3% oil content) 179
15
Table B1.52: Plastic limit data for soil 5 (5.3% oil content) 179
Table B1.53: Liquid limit data for soil 5 (7.1% oil content) 180
Table B1.54: Plastic limit data for soil 5 (7.1% oil content) 180
Table B2.1: Oil loss test for soil 1 181
Table B2.2: Oil loss test for soil 2 181
Table B2.3: Oil loss test for soil 3 181
Table B2.4: Oil loss test for soil 4 182
Table B2.5: Oil loss test for soil 5 182
Table B2.6 Oil loss (g) per mass of oil (g), in percentage 182
Table B3: Atterberg limits of soils 183
Table B4: Total fluid content at Atterberg limits and plasticity of soils 184
Table C1.1: Compaction data for soil 1 (0.0% oil content) 185
Table C1.2: Compaction data for soil 1 (1.8% oil content) 185
Table C1.3: Compaction data for soil 1 (3.5% oil content) 185
Table C1.4: Compaction data for soil 1 (5.3% oil content) 186
Table C1.5: Compaction data for soil 1 (7.1% oil content) 186
Table C1.6: Compaction data for soil 2 (0.0% oil content) 187
Table C1.7: Compaction data for soil 2 (1.8% oil content) 187
16
Table C1.8: Compaction data for soil 2 (3.5% oil content) 187
Table C1.9: Compaction data for soil 2 (5.3% oil content) 188
Table C1.10: Compaction data for soil 2 (7.1% oil content) 188
Table C1.11: Compaction data for soil 3 (0.0% oil content) 189
Table C1.12: Compaction data for soil 3 (1.8% oil content) 189
Table C1.13: Compaction data for soil 3 (3.5% oil content) 189
Table C1.14: Compaction data for soil 3 (5.3% oil content) 190
Table C1.15: Compaction data for soil 3 (7.1% oil content) 190
Table C1.16: Compaction data for soil 4 (0.0% oil content) 191
Table C1.17: Compaction data for soil 4 (1.8% oil content) 191
Table C1.18: Compaction data for soil 4 (3.5% oil content) 191
Table C1.19: Compaction data for soil 4 (5.3% oil content) 192
Table C1.20: Compaction data for soil 4 (7.1% oil content) 192
Table C1.21: Compaction data for soil 5 (0.0% oil content) 193
Table C1.22: Compaction data for soil 5 (1.8% oil content) 193
Table C1.23: Compaction data for soil 5 (3.5% oil content) 193
Table C1.24: Compaction data for soil 5 (5.3% oil content) 194
Table C1.25: Compaction data for soil 5 (7.1% oil content) 194
17
Table C2: Variation of maximum dry density with optimum water content of soils 195
Table C3: Variation of maximum dry density with optimum total fluid content
of soils 195
Table C4: Variation of maximum dry density with optimum water content of soils
used by some previous researchers. 196
Table C5: Variation of maximum dry density with optimum total fluid content of soils
used by some previous researchers. 197
Table D1.1: Plasticity and compaction characteristics of soil 1 198
Table D1.2: Plasticity and compaction characteristics of soil 2 198
Table D1.3: Plasticity and compaction characteristics of soil 3 198
Table D1.4: Plasticity and compaction characteristics of soil 4 199
Table D1.5: Plasticity and compaction characteristics of soil 5 199
Table E1.1: Quantity of flow, Q (ml) in 5 mins for soil 1 (0.0% oil content) 200
Table E1.2: Quantity of flow, Q (ml) in 5 mins for soil 1 (1.8% oil content) 200
Table E1.3: Quantity of flow, Q (ml) in 5 mins for soil 1 (3.5% oil content) 200
Table E1.4: Quantity of flow, Q (ml) in 5 mins for soil 1 (5.3% oil content) 201
Table E1.5: Quantity of flow, Q (ml) in 10 mins for soil 1 (7.1% oil content) 201
Table E1.6: Quantity of flow, Q (ml) in 5 mins for soil 2 (0.0% oil content) 202
Table E1.7: Quantity of flow, Q (ml) in 5 mins for soil 2 (1.8% oil content) 202
18
Table E1.8: Quantity of flow, Q (ml) in 5 mins for soil 2 (3.5% oil content) 202
Table E1.9: Quantity of flow, Q (ml) in 5 mins for soil 2 (5.3% oil content) 203
Table E1.10: Quantity of flow, Q (ml) in 10 mins for soil 2 (7.1% oil content) 203
Table E1.11: Quantity of flow, Q (ml) in 5 mins for soil 3 (0.0% oil content) 204
Table E1.12: Quantity of flow, Q (ml) in 5 mins for soil 3 (1.8% oil content) 204
Table E1.13: Quantity of flow, Q (ml) in 5 mins for soil 3 (3.5% oil content) 204
Table E1.14: Quantity of flow, Q (ml) in 5 mins for soil 3 (5.3% oil content) 205
Table E1.15: Quantity of flow, Q (ml) in 10 mins for soil 3 (7.1% oil content) 205
Table E1.16: Quantity of flow, Q (ml) in 5 mins for soil 4 (0.0% oil content) 206
Table E1.17: Quantity of flow, Q (ml) in 5 mins for soil 4 (1.8% oil content) 206
Table E1.18: Quantity of flow, Q (ml) in 5 mins for soil 4 (3.5% oil content) 206
Table E1.19: Quantity of flow, Q (ml) in 10 mins for soil 4 (5.3% oil content) 207
Table E1.20: Quantity of flow, Q (ml) in 10 mins for soil 4 (7.1% oil content) 207
Table E1.21: Quantity of flow, Q (ml) in 5 mins for soil 5 (0.0% oil content) 208
Table E1.22: Quantity of flow, Q (ml) in 5 mins for soil 5 (1.8% oil content) 208
Table E1.23: Quantity of flow, Q (ml) in 10 mins for soil 5 (3.5% oil content) 208
Table E1.24: Quantity of flow, Q (ml) in 10 mins for soil 5 (5.3% oil content) 209
Table E1.25: Quantity of flow, Q (ml) in 20 mins for soil 5 (7.1% oil content) 209
19
Table E2: Hydraulic conductivity of soils 209
Table F1.1: Plasticity characteristics and hydraulic conductivity of soil 1 210
Table F1.2: Plasticity characteristics and hydraulic conductivity of soil 2 210
Table F1.3: Plasticity characteristics and hydraulic conductivity of soil 3 210
Table F1.4: Plasticity characteristics and hydraulic conductivity of soil 4 211
Table F1.5: Plasticity characteristics and hydraulic conductivity of soil 5 211
Table G1.1: Compaction characteristics and hydraulic conductivity of soil 1 212
Table G1.2: Compaction characteristics and hydraulic conductivity of soil 2 212
Table G1.3: Compaction characteristics and hydraulic conductivity of soil 3 212
Table G1.4: Compaction characteristics and hydraulic conductivity of soil 4 213
Table G1.5: Compaction characteristics and hydraulic conductivity of soil 5 213
LIST OF FIGURES
Figure 2.1: Aggregate size distribution curves of uncontaminated and contaminated
soils (Ijimdiya, 2012) 40
Figure 2.2: Atterberg limits of low plasticity contaminated clay (Khosravi et al,
2013) 42
Figure 2.3: Atterberg limits for contaminated basaltic grade V soil (Rahman et al,
2010) 43
20
Figure 2.4: Atterberg limits for contaminated basaltic grade VI soil (Rahman et al,
2010) 43
Figure 2.5: Atterberg limits for contaminated granitic sandy loam soils (Rahman et al,
2011) 45
Figure 2.6: Atterberg limits for contaminated metasedimentary soils (Rahman et
al, 2011) 45
Figure 2.7: Variation of plasticity index with oil content (Ijimdiya, 2012) 46
Figure 2.8: Dry density and water content for contaminated and uncontaminated high
plasticity clay (Rehman et al, 2007) 48
Figure 2.9: Oil lubricating high plasticity clay (Rehman et al, 2007) 48
Figure 2.10: Compaction curve for metasedimentary soils (Rahman et al, 2011) 49
Figure 2.11: Compaction curves for poorly graded sand (Al Sanad et al, 1995) 50
Figure 2.12: Compaction curves for poorly graded sand (Khamehchiyan et al ,
2007) 51
Figure 2.13: Compaction curves for sand with 5 to 15% silt (Khamehchiyan et al,
2007) 51
Figure 2.14: Compaction curves for low plasticity clay (Khamehchiyan et al, 2007) 51
Figure 2.15: Compaction curves for grade V basaltic soils (Rahman et al, 2010) 53
Figure 2.16: Compaction curves for grade VI basaltic soil (Rahman et al, 2010) 53
Figure 2.17: Compaction curve for granitic sandy loam soil (Rahman et al, 2011) 54
21
Figure 2.18: Hydraulic conductivity of poorly graded sand (Shin and Das, 2000) 56
Figure 2.19: Variation of hydraulic conductivity with oil contents in sand with
5 to 15% silt, low plasticity silt and low plasticity clay (Rojas et al,
2003) 57
Figure 2.20: Variation of hydraulic conductivity with oil palm biodiesel content
(Chew and Lee, 2006) 58
Figure 3.1: Particle size distribution of bentonite, kaolinite and sand 61
Figure 3.2: Aggregate size distribution curve of uncontaminated soil mixtures
and sand 64
Figure 3.3: Aggregate size distribution curve of uncontaminated and contaminated
soil 1 72
Figure 3.4: Liquid limit of uncontaminated soil 1 74
Figure 3.5: Compaction curves of uncontaminated and contaminated soil 1 using
water content 78
Figure 3.6: Compaction curves of uncontaminated and contaminated soil 1 using
total fluid content 78
Figure 3.7: Hydraulic conductivity test set up – Rowe cell (vertical flow) 81
Figure 4.1: Aggregate size distribution of soils 86
Figure 4.2: Soil clods on (a ) 2mm sieve (b) 0.425mm sieve for soil 1 (7.1% oil
content) 88
Figure 4.3: Grading modulus of oil contaminated soils 89
Figure 4.4: Atterberg limits and plasticity index of soils 91
Figure 4.5: Total fluid content at Atterberg limits and plasticity index of soils 92
22
Figure 4.6: Compaction of uncontaminated and contaminated soils 96
Figure 4.7: Variation of dry density with total fluid content for metasedimentary
soils (Rahman et al, 2011) 102
Figure 4.8: Variation of dry density with total fluid content for poorly graded sand
(Al Sanad et al, 1995) 105
Figure 4.9: Variation of dry density with total fluid content for poorly graded sand
(Khamehchiyan et al , 2007) 105
Figure 4.10: Variation of dry density with total fluid content for sand with 5 to 15%
silt (Khamehchiyan et al , 2007) 106
Figure 4.11: Variation of dry density with total fluid content for low plasticity clay
(Khamehchiyan et al , 2007) 106
Figure 4.12: Variation of dry density with total fluid content for basaltic grade V
soils (Rahman et al, 2010) 107
Figure 4.13: Variation of dry density with total fluid content for basaltic grade VI
soils (Rahman et al, 2010) 107
Figure 4.14: Variation of dry density with total fluid content for granitic sandy
loam (Rahman et al, 2011) 108
Figure 4.15: Variation of maximum dry density with optimum water content,
optimum total fluid content and plasticity characteristics of soils 108
Figure 4.16: Variation of hydraulic conductivity with oil content 110
Figure 4.17: Variation of hydraulic conductivity with plasticity characteristics of
soils 111
23
Figure 4.18: Variation of hydraulic conductivity with plasticity characteristics of
soils 116
Figure 4.19: Compaction characteristics and hydraulic conductivity of soils 118
Figure A1: Coefficient of uniformity and coefficient of curvature for sand 132
Figure A4.1: Calibration of hydrometer 135
Figure A4.2: Calibration graph for hydrometer 136
Figure B1.1: Liquid limit of bentonite 154
Figure B1.2: Liquid limit of kaolinite 155
Figure B1.3: Liquid limit of soil 1 (0.0% oil content) 156
Figure: B1.4: Liquid limit of soil 1 (1.8% oil content) 157
Figure B1.5: Liquid limit of soil 1 (3.5% oil content) 158
Figure B1.6: Liquid limit of soil 1 (5.3% oil content) 159
Figure B1.7: Liquid limit of soil 1 (7.1% oil content) 160
Figure B1.8: Liquid limit of soil 2 (0.0% oil content) 161
Figure B1.9: Liquid limit of soil 2 (1.8% oil content) 162
Figure B1.10: Liquid limit of soil 2 (3.5% oil content) 163
Figure B1.11: Liquid limit of soil 2 (5.3% oil content) 164
Figure B1.12: Liquid limit of soil 2 (7.1% oil content) 165
Figure B1.13: Liquid limit of soil 3 (0.0% oil content) 166
24
Figure B1.14: Liquid limit of soil 3 (1.8% oil content). 167
Figure B1.15: Liquid limit of soil 3 (3.5% oil content) 168
Figure B1.16: Liquid limit of soil 3 (5.3% oil content) 169
Figure B1.17: Liquid limit of soil 3 (7.1% oil content) 170
Figure B1.18: Liquid limit of soil 4 (0.0% oil content) 171
Figure B1.19: Liquid limit of soil 4 (1.8% oil content) 172
Figure B1.20: Liquid limit of soil 4 (3.5% oil content) 173
Figure B1.21: Liquid limit of soil 4 (5.3% oil content) 174
Figure B1.22: Liquid limit of soil 4 (7.1% oil content) 175
Figure B1.23: Liquid limit of soil 5 (0.0% oil content) 176
Figure B1.24: Liquid limit of soil 5 (1.8% oil content) 177
Figure B1.25: Liquid limit of soil 5 (3.5% oil content) 178
Figure B1.26: Liquid limit of soil 5 (5.3% oil content) 179
Figure B1.27: Liquid limit of soil 5 (7.1% oil content) 180
LIST OF ABBREVIATIONS
CH High Plasticity Clay
CL Low Plasticity Clay
GM Grading Modulus
25
ML Low Plasticity Silt
MSDS Material and Safety Data Sheet
OMC Optimum Water Content (%)
RHA Rice Husk Ash
SM Silty Sand
SP Poorly Graded Sand
SW Well Graded Sand
XRD X Ray Diffraction
LIST OF SYMBOLS
Non Greek symbols
Cc Coefficient of Curvature
Cu Coefficient of Uniformity
D Sample Diameter (mm)
d Drain Outlet Diameter (mm)
Gs Specific Gravity
H Sample Height (mm)
M Mass of Content of Mould (g)
Md Mass of Dry Soil (g)
26
MMB Mass of Mould and Base (g)
Mo Mass of Oil (g)
Moilr Mass of Oil Residue (g)
Mols Mass of Oil Loss (g)
Mor Mass of Oil Residue (g)
Mr Mass of Dried Contaminated Soil (g)
Ms Mass of Soil Solids (g)
MSMB Mass of Uncontaminated Soil, Mould and Base (g)
Msl Mass of Solids (g)
Msoil Mass of Uncontaminated Soil
Msolids Mass of Solids (g)
Mt Mass of Wet Contaminated Soil (g)
Mv Mass of Loss of Oil
Mw Mass of Loss of Water (g)
Mwt Mass of Water (g)
oc Oil Content (%)
OL Oil Loss (%)
P0.075 Percentage Retained on 0.075mm Sieve (%)
27
P0.425 Percentage Retained on 0.425mm Sieve (%)
P2 Percentage Retained on 2mm Sieve (%)
Q Quantity of Flow (ml)
q Flow Rate (ml/min)
t time (mins)
V Volume of Mould
w Water Content (%)
wd Water Content at a Dry Unit Weight (%)
wo Water Content of Oil Contaminated Soil (%)
wu Water Content of Uncontaminated Soil (%)
Greek symbols
ɣav Unit Weight at Zero Air Voids (kN/m3)
ɣw Unit Weight of Water (kN/m3)
∆p Pressure Difference (kPa)
ρ Bulk Density (g/cm3)
ρd Dry Density (g/cm3)
Word count: 37536
28
Name of the University: The University of Manchester Submitted by: Miebaka Ransome Daka Degree Title: Master of Philosophy Thesis Title: Geotechnical properties of oil contaminated soil Date: January 27, 2015
ABSTRACT
This research investigated the effect of oil contamination on grading modulus, Atterberg limits, compaction, and hydraulic conductivity of bentonite-kaolinite-sand mixtures. An area that lacked experimental data was chosen for the research. Data on oil contaminated soil containing montmorillionte were scarce; hence, bentonite-kaolinite-sand mixtures at oil contents of 0.0, 1.8, 3.5, 5.3 and 7.1% by dry mass of the soil were used for the study.
The first aspect of the study was the use of grading modulus to confirm reduction of fine aggregate in the contaminated soils. Atterberg limits tests were performed to determine the liquid and plastic limits of uncontaminated and contaminated soils. Proctor compaction tests were performed to determine the compaction characteristics of the oil contaminated soils. Hydraulic conductivity tests were performed using a Rowe cell. Aggregate size distribution analysis of the oil contaminated soil mixtures showed that the aggregate size distribution curves shifted from finer to coarser as the oil content increased, indicating that oil contamination caused reduction of fine aggregate in the soil while forming soil clods. The Atterberg limits tests showed that the liquid limit and plastic limit increased as oil contamination increased in the soil mixtures. The plasticity index of the soils also increased as oil contamination increased. It was deduced from the research that soils 1 and 2 had plasticity index below 65%, those of soils 3, 4 and 5 were above 65%. However, soil 3 had plasticity index close to 65. The results of the compaction tests with respect to maximum dry density and optimum water content showed that oil contamination resulted in decreased maximum dry density and optimum water content in the five soils. The hydraulic conductivity of soil mixtures decreased as oil contamination increased. Generally, soils 3, 4 and 5 had hydraulic conductivities that were close to 1 x 10-9m/s. Soil 3 had plasticity index close to 65% and hydraulic conductivity less than 1 x 10-9m/s, hence, it is suitable as soil liner for landfill. However, soils with plasticity index above 65% are difficult to handle.
29
DEDICATION
This research work is dedicated to all those who spend hours carrying out research in
order to make the world a better place for living.
30
DECLARATION
I hereby declare that this dissertation is an original research and was never submitted to
another university or this university. This dissertation was entirely carried out by me,
however, there is reference made to other research works.
---------------------------------- Miebaka Ransome Daka
31
COPYRIGHT STATEMENT
i. The author of this thesis (including any appendices and/ or schedules to this thesis)
owns certain copyright or related rights in it (the “Copyright”) and he has given The
University of Manchester certain rights to use such Copyright, including for
administrative purposes.
ii. Copies of this thesis, either in full or in extracts and whether in hand or electronic
copy, may be made only in accordance with the Copyright, Designs and Patents Act
1988 (as amended) and regulations issued under it or, where appropriate, in
accordance with licensing agreements which the University has from time to time.
This page must form part of any such copies made.
iii. The ownership of certain Copyright, patents, designs, trade marks and other
intellectual property (the “Intellectual Property”) and any reproductions of copyright
works in the thesis, for example graphs and tables (“Reproductions”), which may be
described in this thesis, may not be owned by the author and may be owned by third
parties. Such Intellectual Property and Reproductions cannot and must not be made
available for use without the prior written permission of the owner(s) of the relevant
Intellectual Property and/or Reproductions.
iv. Further information on the conditions under which disclosure, publication and
commercialisation of this thesis, the Copyright and any Intellectual Property and/or
Reproductions described in it may take place is available in the University IP policy
(http://documents.manchester.ac.uk/DocuInfo.aspx?DocID=487), in any relevant
Thesis restriction declarations deposited in the University Library, The University
Library’s regulations (http://www.manchester.ac.uk/library/aboutus/regulations) and
in The University’s policy on Presentation of Theses.
32
ACKNOWLEDGEMENT
I express my thanks to Dr. Syed Mohd Ahmad, Dr Rob Young, and Dr Hossam Abuel
Naga for their contributions that made this research work a success.
I am grateful to the Rivers State Sustainable Development Agency for sponsoring this
study.
I am also grateful to Prof. Ayotamuno Miebaka Josiah, Prof. Daka Erema, Associate
Prof. A. J. Akor, Engineer Daka Otonye and Mrs Gladys Miebaka Daka for their
support.
I am grateful to all staff in the School of Mechanical, Aerospace and Civil Engineering
for their encouragement and support.
33
CHAPTER 1
INTRODUCTION
This section contains the background of the main problem the research work sought to
address, the aim, objectives, scope of research work and structure of thesis.
1.1 Background
Oil spillage occurs as a result of wars, accidents, drilling, storage, transportation of
product, and natural disasters. Singh et al (2008) stated that when oil is released, it
resides in the soil system, in the pore space of the soil, modifying the behaviour of the
soil. Crude oil was released into the soil when storage tanks and well heads were
destroyed in Kuwait during the gulf war of August 2, 1990 to February 28, 1991 (Al-
Sanad et al, 1995; Rehman et al, 2007). Despite the good oil tanker maintenance
culture, oil leaked from storage tanks and polluted the soil in the United States of
America (Patel, 2011). Ijimdiya (2012) stated that due to oil exploration, oil was
released to the environment in the Niger Delta of Nigeria, exposing the area to
environmental degradation.
Oil leakage into soil results in contamination and there is a need for bioremediation
(Khamehchiyan et al, 2007). A basic step for effective bioremediation is an
understanding on how the geotechnical properties of the soil are affected by the oil
contamination. Geotechnical testing of soil aids in finding an alternative usage for the
contaminated soil (Al-Duwaisan and Al-Naseem, 2011). A few studies have been
performed by experts to evaluate the effects of oil contamination (Khamehchiyan et al,
2007; Rehman et al, 2007; Rahman et al, 2010; Ijimdiya, 2012). Khamehchiyan et al
34
(2007) stated that proposals made for the use of soil with oil content included that of
using it for road base material and topping layer in car parks after mixing with
aggregates. Treatment methods for the contaminated soil included bioremediation, soil
washing and incineration. Soil contamination is affected by the type of contaminant as
well as the soil’s properties (Fine et al, 1997). Hence, an adequate understanding of the
geotechnical characteristics of soils contaminated by oil is imperative.
Sand and clay mixtures are used as soil liners for landfill. When clay is scarce, a
mixture of sand and clay is used (Mohamedzein et al, 2003). Soil mixtures are
commonly those of sand, kaolinite and bentonite or sand and bentonite (Muntohar,
2003). When sand is mixed with natural clay and bentonite, the mixture can be used as a
water barrier in landfills (Mohamedzein et al, 2003). Bentonite-kaolinite-sand mixtures
are used as vertical cut-off walls for containment of movement of fluids (Evans, 1993).
Evaluation of the effect of oil on contaminated soil using crude oil or its oil product as
its representative was important as it could aid in decisions on using the material for
alternative purposes like construction of slabs and support of structures (Mohamedzein
et al, 2003).
Bioremediation of crude oil contaminated soils involves hydrocarbon utilising bacteria
degrading oil in the presence of water (Kogbara, 2008). When water moves to an
initially dry contaminated soil, the rate of oil degradation by the bacteria increases as it
feeds on nutrients that dissolve in water. It is therefore pertinent to determine the
hydraulic conductivity of water in the oil contaminated soil, in order to suggest area of
contaminated soil with increased bacterial degradation of oil. Incineration is an
35
alternative to bioremediation (Khamehchiyan et al, 2007); in this case, the soil is
excavated and burnt in an incinerator.
It is pertinent to evaluate the effect of oil on bentonite-kaolinite-sand mixtures as
bentonite is used as buffer and backfill material in the containment of radioactive
wastes (Akgun, 2010), mine effluents (Gratchev et al, 2012), exploratory boreholes and
diversion tunnels (Pusch, 1992), waste leachates and water barrier (Chalermyanont and
Arrykul, 2005).
This research focused on investigating the geotechnical properties of soil, using low oil
content. According to Khamehchiyan et al (2007), when the oil content in soil is below
16%, oil does not drain out from soil; similarly, Erten et al (2011) stated that when oil
content in soil is low, oil would not be expelled from the soil during geotechnical tests.
Al-Sanad et al (1995) stated that field condition at a contaminated site in Kuwait
contained a maximum of 6% by dry weight of the soil. In the light of the
aforementioned, this study investigated the geotechnical properties of bentonite-
kaolinite-sand mixtures at low oil contents limited to 7.1%.
1.2 Problem statement
Oil contamination alters the geotechnical properties of soils. There were few research
works that assessed the effect of oil contamination on geotechnical properties of soils.
The research works were mainly on soils that did not contain montmorillonite.
This research work investigated the effect of oil on soils that contained montmorillonite
by using bentonite-kaolinite-sand mixtures. Bentonite contained montmorillonite with
swelling characteristic and this influenced the behaviour of the soil mixture distinctly
36
from those without bentonite. The bentonite-kaolinite-sand mixture was used in the
study to fill the void created by lack of data on effects of oil on soils that contain
montmorillonite.
1.3 Aim and objectives
The aim of the study was to evaluate the geotechnical properties of oil contaminated
bentonite-kaolinte-sand mixture. The particular objectives were to investigate the effect
of oil contamination on grading modulus, Atterberg limits (liquid limit and plastic
limit), compaction, and hydraulic conductivity of bentonite-kaolinite-sand mixture.
1.4 Scope of the study
The research work was limited to the evaluation of the effect of oil contamination on
bentonite-kaolinite-sand mixtures. The geotechnical properties investigated for the oil
contaminated soils were grading modulus, Atterberg limits, compaction and hydraulic
conductivity.
This study evaluated both variation of maximum dry density with optimum water
content and variation of maximum dry density with optimum total fluid content1 for the
compaction test. Previous studies did not include variation of maximum dry density
with total fluid content.
1 Total fluid content - sum of water content and oil content in the soil.
37
1.5 Limitations of the study
The oil was mixed into dry soil for all tests before addition of water. Hence, effect of oil
contamination on soils that initially contained water was not investigated.
The liquid limit test was not carried out by adding appropriate amount of oil, rather,
appropriate amount of water was added to a soil containing a specific amount of oil.
The oil loss was considered as insignificant for the Atterberg limit tests.
Known water contents were added to the oil contaminated soil used for the compaction
test. There was no further determination of water contents by oven drying method. The
transfer of soil from the container to the mould with its extension and vice versa was
done with great care to avoid soil loss. The test was not performed by adding oil to soils
that already contained water.
Chemical reactions in the soil were not investigated.
Specific gravity tests were not done for the uncontaminated and oil contaminated soils;
hence, zero air void and saturation lines were not drawn for the compaction curves in
this study. Variation of dry density with water content in g/cm3 was used for the
compaction curves for consistency and comparison with those of other researchers. The
equation for zero air void line is ɣav = [ɣw Gs/(1 + 0.01wdGs)], with ɣav = unit weight at
zero air voids, ɣw = unit weight of water, Gs = specific gravity of a soil and wd = water
content at a dry unit weight. This involves unit weight and results are in kN/m3. This
study and previous research works used density (g/cm3) and not dry unit weight
(kN/m3). When the acceleration due to gravity is used to multiply the density, the result
is a different value, expressed as that for force (kN) per m3 (Fratta et al, 2007).
38
Scanning Electron Microscope imaging was not performed for the uncontaminated and
oil contaminated soils.
Numerical analysis was not performed in this study.
1.6 Structure of the thesis
The thesis introduces the topic in chapter 1 and in chapter 2 evaluates literature on
geotechnical properties of oil contaminated soil. Chapter 3 includes the materials and
experimental procedures, clearly mentioning the materials and explaining the
procedures used for the experiment. Chapter 4 presents the experimental results and
discussion while chapter 5 contains the conclusion and recommendation. The
Appendices contain experimental results that were not included in Chapter 4.
39
CHAPTER 2
LITERATURE REVIEW
This literature review evaluated all aspects of literature related to this research work. It
reviewed literature on geotechnical properties of soil after contamination with crude oil
or its derivatives, an approach that enables a thorough understanding of this important
area of research.
2.1 Geotechnical properties of oil contaminated soils
This section reviewed literature on how geotechnical properties of soils are affected
when the soils are contaminated. The manner in which oil affects a soil would
determine the approach of handling the contaminated soil with the aim of putting it into
alternative use. Oil contamination has become a major problem, and there is clamour for
remediation of contaminated soil. Patel (2011) stated that in spite of the different
approaches to prevent oil leakage, 25% of oil petroleum associated products leak in the
United States of America alone, contaminating the soil. An understanding on how oil
affects the properties of soil is a basic step in designing an effective remediation system.
The variations in findings on effect of oil on the geotechnical properties of soil are due
to variation in oil composition and soil mineralogy (Khosravi et al, 2013). The research
on geotechnical properties of oil contaminated soils is an important area of research.
Few studies are available in this area and this section reviews previous studies.
40
2.1.1 Aggregate size distribution2 of oil contaminated soils
Ijimdiya (2012) investigated the effect of oil contamination on aggregate size
distribution. The soil used was reddish brown and obtained from a borrow pit at Shika,
Zaria, Nigeria. The soil had a large amount of kaolinite clay mineral and 87% silt.
Various concentrations of the oil (1, 2, 3, 4, 5 and 6% oil content) were mixed with the
dry soil sample. The oil contaminated soil was passed through 2.4 to 0.075mm sieve
sizes and percentage of soil that passed through each sieve was determined to get the
aggregate size distribution. Figure 2.1 shows the aggregate size distribution curves of
the contaminated and uncontaminated soils. The aggregate size distribution curve
shifted from finer to coarser as oil contamination increased from 0 to 6% by dry weight
of the soil.
Figure 2.1: Aggregate size distribution curves of uncontaminated and contaminated
soils (Ijimdiya, 2012).
2 Aggregate size distribution curve is obtained using percentage of soil that passed through various sieves in sieve analysis. Oil contamination resulted in flocculation of soil composition into different aggregate sizes, hence, oil contaminated soils have varying aggregate size distribution curves.
41
2.1.1.1 Summary on aggregate size distribution of oil contaminated soils
The study of Ijimdiya (2012) showed that an increase in oil content shifted the
aggregate size distribution curve from finer to coarser.
There is a need to carry out further investigations on how oil affects the aggregate size
distribution curve using different soils as a contribution to knowledge.
2.1.2 Atterberg limits of oil contaminated soils
The Atterberg limits tests are used for the plasticity characterization of soils. Atterberg
limits of soils are used to identify, describe and classify soils.
2.1.2.1 Oil contamination increases the Atterberg limits
Rehman et al (2007) investigated the geotechnical behaviour of oil contaminated high
plasticity clay. The soil was air dried, pulverized, sieved through 0.420mm sieve, mixed
with crude oil, and then air dried. Atterberg limits test was carried out for the soil.
Table 2.1 shows that when crude oil was added, Atterberg limits and plasticity index
increased because oil gave additional cohesion to the clay particles.
Property Uncontaminated clay Contaminated clay (oil content was not stated)
Liquid limit ( % ) 172 185
Plastic limit ( % ) 48 50
Plasticity index 124 135
Table 2.1: Properties of clay, before and after contamination (Rehman et al, 2007).
42
Khosravi et al (2013) studied the effect of oil contamination on Atterberg limits by
contaminating a low plasticity clay containing kaolinite with oil contents of 2, 4, 6, 12
and 16% by dry weight of the soil. The liquid limit and the plasticity index of the soil
increased as the oil content increased in the soil from 0 to 12% as shown in Figure 2.2.
However, there was a reduction in the aforementioned parameters from 12 to 16% oil
content because the oil reduced the cohesion of the soil.
Figure 2.2: Atterberg limits of low plasticity contaminated clay (Khosravi et al, 2013).
2.1.2.2 Oil contamination decreases Atterberg limits
Rahman et al (2010) studied the effect of oil contamination on the geotechnical
properties of basaltic grade V3 and VI4 residual soils. The soils were of loam and silty
3 Basaltic grade V soil - residual soil from igneous or volcanic rock that still possesses
the original soil texture. 4 Basaltic grade VI soil - residual soil from igneous or volcanic rock that no longer has
its original rock texture.
43
textures. XRD analysis indicated that the soil had feldspar, quartz and clay minerals of
kaolinite and contained little amount of gibbsite and goethite (Gibbsite is an aluminium
ore while goethite is a product of iron rich minerals). Atterberg limits were determined
for various levels of oil contamination in accordance with BS 1377 (1990). The results
for Atterberg limits were shown in Figures 2.3 and 2.4 for the basaltic grade V and
grade VI soils respectively. It shows that liquid limit and the plastic limit are reduced
when the oil content is increased. This was because oil occupied more space without
adding more cohesion to the soil.
Figure 2.3: Atterberg limits for contaminated basaltic grade V soil (Rahman et al,
2010).
Figure 2.4: Atterberg limits for contaminated basaltic grade VI soil (Rahman et al,
2010).
44
Rahman et al (2011) investigated the effect of oil on the Atterberg limits of granitic5
sandy loam and metasedimentary6 soils. The soil samples in the study were taken from
in situ weathered granitic and sedimentary rocks. The granitic soil had 64% sand, 34%
silt and 2% clay while the metasedimentary soil consisted of gravel, sand, silt and clay
of 34%, 37%, 27% and 2% respectively. The minerals in the granitic soil were quartz,
kaolinite and gibbsite while the metasedimentary soil consisted of quartz and kaolinite.
They used a component of crude oil at different percentages of 0 to 16 percent by dry
weight of soil. Disturbed soil specimens were used and tests were done in accordance
with BS 1377 (1990).
The Atterberg limits reduced in the granitic sandy loam and metasedimentary soils as
shown in Figures 2.5 and 2.6. Khamehchiyan et al (2007) stated that oil caused a
reduction in the amount of water that surrounded the clay and sand particles. The first
contact of the oil was with the soil and not the water. Oil contaminated soil deform as
liquid or plastic in the presence of water. This was less when oil content increased,
hence, liquid limit and plastic limits generally reduced.
5 Granitic soil - soil formed from granite, an igneous rock. 6 Metasedimentary soil - soil formed from sedimentary rock that have undergone
metarmophism.
45
Figure 2.5 Atterberg limits for contaminated granitic sandy loam soils (Rahman et al,
2011).
Figure 2.6 Atterberg limits for contaminated metasedimentary soils (Rahman et al,
2011).
Ijimdiya (2012) studied the effect of oil contamination on plasticity characteristics of
lateritic soil. The material used for determination of the plasticity characteristic was soil
that passed through a sieve of 0.425mm. Liquid and plastic limits were determined
using BS 1377 (1990). It was found that 2 percent oil content reduced the plasticity
46
index from 16.0 percent to 15.5 percent as shown in Figure 2.7. When the soil was
mixed with oil content of 1, 2, 3, 4, 5 and 6 percent, it was confirmed that clods were
formed, hence, crude oil could glue soil particles together, thereby reducing the
influence of water on the soil particles.
Figure 2.7: Variation of plasticity index with oil content (Ijimdiya, 2012).
2.1.2.3 Summary on Atterberg limits of oil contaminated soils
Oil contamination affected the Atterberg limits of soils. There is a lack of consensus on
how oil contamination affects the Atterberg limits of the soil, however, it is seen in the
literature that oil can either increase or decrease the Atterberg limits of the soil. There is
need to use different soils to investigate the effect of oil on the Atterberg limits of soils.
This will contribute to existing knowledge.
A summary on increase or decrease of Atterberg limits as oil content increased in soil
from the literature review is shown in Table 2.2.
47
Reference Soils Atterberg limits Rehman et al (2007) High plasticity clay Atterberg limits increased Khosravi et al (2013) Low plasticity clay
Rahman et al (2010) Basaltic grade V
Atterberg limits decreased
Basaltic grade VI
Rahman et al (2011) Granitic sandy loam Metasedimentary
Ijimdiya (2012) Lateritic
Table 2.2: Summary on Atterberg limits
2.1.3 Compaction of oil contaminated soils
Compaction is the expulsion of air from voids of soils by compressing the soil particles
through the application of mechanical energy. When a soil is compacted, a relationship
between dry density and both water content and total fluid content can be derived.
2.1.3.1 Oil contamination, increase in maximum dry density and decrease in
optimum water content
Rehman et al (2007) investigated the compaction characteristics of oil contaminated
high plasticity clay. They used the standard Proctor compaction test and the variation of
maximum dry density with optimum water content of the soil is shown in Figure 2.8.
The contaminated soil (oil content was not stated) had a higher maximum dry density at
lower optimum water content; this was because the oil lubricated the soil aggregates.
Figure 2.9 shows the oil lubricating the soil.
48
Figure 2.8: Dry density and water content for contaminated and uncontaminated high
plasticity clay (Rehman et al, 2007).
Figure 2.9: Oil lubricating high plasticity clay (Rehman et al, 2007).
Rahman et al (2011) studied the compaction characteristics of oil contaminated
metasedimentary soils (silty clay loam), by using the standard Proctor compaction test.
Generally, oil contamination resulted in an increase in the maximum dry density of the
soil, accompanied by a reduction in the optimum water content as shown in Figure 2.10;
49
The oil glued more of the soil aggregates together as the oil content increased from 0 to
12%. However, the maximum dry density reduced at 16% oil content because the oil
content was in excess and caused separation of soil voids.
Figure 2.10: Compaction curve for metasedimentary soils (Rahman et al, 2011).
2.1.3.2 Oil contamination, decrease in maximum dry density and decrease in
optimum water content
Al-Sanad et al (1995) investigated the effect of oil contamination on poorly graded
sand. The soil was mixed with 2, 4, and 6% oil content by dry weight of the soil and
compacted with 4.5kg rammer. Compaction performed using 4.5kg rammer results in
higher soil densification than that of 2.5kg for the standard Proctor test rammer. The
compaction curves are shown in Figure 2.11.
50
Figure 2.11: Compaction curves for poorly graded sand (Al Sanad et al, 1995).
Generally, there was a decrease in the maximum dry density as the oil content increased
from 2 to 6% due to excessive lubrication of the soil. However, maximum dry density
increased as the oil content increased from 0 to 2% because the oil gave cohesion to the
soil at 2%. When oil content was above 2%, the oil gave less cohesion to the soil,
resulting in reduced maximum dry density.
Khamehchiyan et al (2007) investigated the effect of crude oil contamination on the
compaction characteristics of Bushehr coastal soils in Iran. The soils were poorly
graded sand, sand with 5 to 15% silt and low plasticity clay. These soils were mixed
with 0, 4, 8, 12 and 16% oil by dry weight of the soils. Compaction was done by the
standard Proctor compaction tests on the contaminated soils. They confirmed that
maximum dry density decreased when the oil content of the soil was increased. Out of
the three soil types, the decrease was more for sand with 5 to 15% silt and low plasticity
clay.
51
The poorly graded sand had a decrease in maximum dry density as oil content increased
in the soil as shown in Figure 2.12, because the sand has large pore spaces and oil
moves easily through these pores with ease. Furthermore, due to the ease of movement
of the oil within the soil pores, the decrease in the maximum dry density is small.
Figure 2.12: Compaction curves for poorly graded sand (Khamehchiyan et al , 2007).
The sand with 5 to 15% oil content had less pore spaces than the poorly graded sand,
consequently, there was no ease of movement of oil as that of sand. However, the oil
content sufficiently lubricated the soil and the maximum dry density decreased with
increase in the oil content as shown in Figure 2.13.
Figure 2.13: Compaction curves for sand with 5 to 15% silt (Khamehchiyan et al ,
2007).
52
The low plasticity clay had smaller particles than the poorly graded sand and the sand
with 5 to 15% silt. However, as oil content increased in the soil, the oil separated the
voids in the soil and this caused a reduction in the maximum dry density of the soil. The
optimum water content in the soil also decreased. The compaction curve of the low
plasticity clay is shown in Figure 2.14.
Figure 2.14: Compaction curves for low plasticity clay (Khamehchiyan et al, 2007).
Rahman et al (2010) investigated the influence of oil on compaction characteristics of
basaltic residual soil. The soils were sticky when wet. Figures 2.15 and 2.16 show the
compaction characteristics of grade V and grade VI basaltic soils respectively, using 2.5
kg rammer, with 300 mm height of drop (BS 1377, 1990).
53
Figure 2.15 Compaction curves for grade V basaltic soils (Rahman et al, 2010).
Figure 2.16 Compaction curves for grade VI basaltic soil (Rahman et al, 2010).
The initial maximum dry densities for the uncontaminated soils were 1.67g/cm3 for
grade V and 1.60g/cm3 for grade VI basaltic soil. The initial optimum water content in
percentage were 24 for grade V and 23 for grade VI basaltic soil. When 4 percent of oil
was added to the soil, the maximum dry density of contaminated grade V soil reduced
54
from 1.67 to 1.50g/cm3 and the reduction continued linearly with increase in oil content
of 8 to 16 percent (Fig 2.15). There was also a decrease in the maximum dry density of
contaminated grade VI soil as oil content was increased (Figure 2.16), but the decrease
was less than that of grade V.
Rahman et al (2011) investigated the effect of oil on compaction characteristics of
granitic sandy loam soil. The maximum dry density reduced as oil contamination
increased in the soil as shown in Figure 2.17 because oil occupied the soil pores rapidly.
Figure 2.17: Compaction curve for granitic sandy loam soil (Rahman et al, 2011).
2.1.3.3 Summary on compaction of oil contaminated soils
The literature review showed that when oil contaminated soils were compacted, the
compaction characteristics of the soils differed because the soil composition differed. It
showed that the maximum dry density increased with increase in oil content, when
Rehman et al (2007) and Rahman et al (2011) compacted an high plasticity clay and
55
metasedimentary soils respectively. On the other hand, the maximum dry density
decreased with an increase in oil content, when Al-Sanad et al (1995), Khamehchiyan et
al (2007), Rahman et al (2010) and Rahman et al (2011) compacted a variety of soils
such as poorly graded sand, sand with 5 to 15% silt, low plasticity clay and basaltic
soils. The lack of consensus on the effect of oil on compaction characteristics warrants a
further study wherein different soil compositions contaminated by oil are compacted to
investigate their compaction characteristics. This will add to existing knowledge in this
area of study.
The summary of increase or decrease in maximum dry density and optimum water
content as oil content increased in soil is shown in Table 2.3.
Reference Soils Maximum dry density(g/cm3)
Optimum water content (%)
Rehman et al (2007) High plasticity clay Increased
Decreased
Rahman et al (2011) Metasedimentary Al-Sanad et al (1995) Poorly graded sand
Decreased
Khamehchiyan et al (2007)
Poorly graded sand Sand with 5 to 15% silt Low plasticity clay
Rahman et al (2010) Grade V (basaltic) Rahman et al (2011)
Grade VI (basaltic) Granitic sandy loam
Table 2.3: Summary of Maximum dry density and optimum water content of soils
2.1.4 Hydraulic conductivity of oil contaminated soils
Hydraulic conductivity is a measure of the movement of water in a soil. Oil
contamination of soil affects the flow rate of water in the soil.
56
2.1.4.1 Oil contamination decreases hydraulic conductivity
Shin and Das (2000) investigated the effect of oil content on the hydraulic conductivity
of oil contaminated poorly graded sand. The soils were mixed with oil contents of 1, 2,
4 and 6% by dry weight of the soils. The kinematic viscosities of engine oil, Oman
crude oil, and lamp oil were 300, 50 and 4 mPas respectively.
Specimens of 100mm diameter and 150mm height were used for constant head
permeability tests. The results of these hydraulic conductivity tests are shown in Figure
2.18.
Figure 2.18 Hydraulic conductivity of poorly graded sand (Shin and Das, 2000).
The hydraulic conductivity of the soil decreased with an increase in the oil content as oil
occupied the pore spaces of the soil.
Soils with higher kinematic viscosities and higher relative densities were found to have
a lower hydraulic conductivity.
Rojas et al (2003) investigated the effect of kinematic viscosity and hydraulic
conductivity of different oil contaminated soils (sand with 5 to 15% silt, low plasticity
57
silt and low plasticity clay).The soils were contaminated with oil content of 2, 4, and
6% by dry weight of the soil. The kinematic viscosities of the oils for gear oil, engine
oil and crude oil were 300, 80 and 3 mPas respectively.
The hydraulic conductivity test was done for the three soils using falling head
permeability test with one back pressure system and deaired water. Standard
geotechnical hydraulic conductivity equation was used as oil does not mix with water
(Silverstein, 1998). The soils were compacted at the maximum dry unit weight, using
4.5kg rammer.
The study confirmed that hydraulic conductivity reduced as the amount of oil increased.
For contaminated soils with oils of higher kinematic viscosities, a larger decrease of the
hydraulic conductivity was observed as shown in Figure 2.19 because there was more
limitation to the flow of water in the pores of soils.
Figure 2.19: Variation of hydraulic conductivity with oil contents in sand with 5 to
15% silt, low plasticity silt and low plasticity clay (Rojas et al, 2003).
58
Chew and Lee (2006) investigated the effect of palm biodiesel on hydraulic
conductivity of poorly graded sand. The palm biodiesel was a blend of 20% palm oil
with 80% petroleum diesel and having a kinematic viscosity of 4 mPas.
The poorly graded sand used for each test was compacted to a relative density of 60%.
Constant head permeability tests were carried out and the hydraulic conductivity of the
contaminated soils are shown in Figure 2.20.
Figure 2.20 Variation of hydraulic conductivity with palm biodiesel content (Chew
and Lee, 2006).
The hydraulic conductivity of the soil decreased as the oil content increased because the
palm biodiesel in the soil pores filled the pores of soil, limiting the flow of water.
2.1.4.2 Summary on hydraulic conductivity of oil contaminated soils
The hydraulic conductivity of the soils decreased as oil contamination increased. It is
necessary to use different soils from those soils used by Shin and Das (2000), Rojas et
al (2003) and Chew and Lee (2006) to investigate the effect of oil on the hydraulic
conductivity because soil behaviour differs.
59
The study of Shin and Das (2000), Rojas et al (2003) and Chew and Lee (2006) showed
that an increase in oil contamination resulted in a decrease of hydraulic conductivity in a
variety of soils such as poorly graded sand, sand with 5 to 15% silt, low plasticity silt
and low plasticity clay.
2.2 Summary of Literature Review
The literature review showed that oil contamination caused reduction of fine aggregate
as evident in the shifting of the aggregate size distribution curve from finer to coarser.
The Atterberg limits, maximum dry density and optimum water content increased or
decreased depending on the kind of soil that was contaminated with oil. The hydraulic
conductivity of oil contaminated soils decreased.
The tests performed by the researchers scarcely contained montmorillionite, hence, a
study on soils that contained montmorillonite was necessary, because montmorillonite
has a different behaviour from those minerals contained in soils of previous research
works because of its swelling characteristic. This research work aimed to fill the gap in
that area by using bentonite- kaolinite-sand mixture as an important study area to
investigate the geotechnical properties of oil contaminated soils by using grading
modulus, compaction and hydraulic conductivity. The standards and equipment used by
the researchers varied, as there were many standards and equipment that could generate
data that were acceptable within the geoenvironmental practice. The main criteria for
choosing the equipment for this important area of research were their ability to generate
data and the British standard was adopted to achieve that purpose. The equipment
chosen to generate data for the study and the experimental procedures are included in
Chapter 3 of this research.
60
CHAPTER 3
MATERIALS AND EXPERIMENTAL PROCEDURES
This chapter presents a description of the materials used for the experiments and the
procedures followed in performing these experiments. Uncontaminated and
contaminated bentonite-kaolinite-sand mixtures were used for the experiments. Oil was
mixed into the soil mixtures for contamination. This study is important as it investigates
the geotechnical properties of oil contaminated sand-clay mixtures with varying
amounts of bentonite and kaolinite.
3.1 Materials
The type of soil and contaminant used for the experimental work are described in this
section.
3.1.1 Properties of soils, mineralogical content of clays and oil characteristics
The soil mixtures used for the experiments contained Wyoming bentonite, China clay
kaolinite and sand while the oil was Shell Tellus oil 68.
3.1.1.1 Particle size distribution of bentonite, kaolinite and sand
The particle size distributions of bentonite, kaolinite (done using a hydrometer analysis)
and sand (done using a dry sieving method) as per BS 1377:1990 are shown in Figure
3.1. The sand was poorly graded with coefficient of uniformity, Cu of 1.7 and gap
graded with coefficient of curvature, Cc of less than 1 (Fig A1). The specific gravity
(Gs) of the sand was 2.64 (Appendix A2), while those for bentonite and kaolinite were
61
2.65 and 2.60 respectively, as shown in Appendix A3. Specific gravity tests were done
in accordance with BS 1377:1990.
Figure 3.1: Particle size distribution of bentonite, kaolinite and sand.
3.1.1.2 Mineralogical content of bentonite and kaolinite
Bentonite and kaolinite are clay soils that contain mostly montmorillonite and kaolin
respectively. The exact locations of the origin of the soils were not included in the
material safety and data sheets of the products, however, the stated mineralogical
content of Wyoming bentonite and China clay kaolinite are shown in Table 3.1.
Mineral Bentonite Kaolinite Sodium montmorillonite (%) 92 0 Kaolin (%) 0 96 Quartz (%) 4 1.6 Feldspar (Albite) (%) 3 0.4 Biotite (%) 1 2
Table 3.1: Mineralogical content of Wyoming bentonite and China clay kaolinite
(MSDS, 2011; WMA, 2013).
62
3.1.1.3 Characteristics of Shell Tellus oil 68
Shell Tellus oil 68 was used for contamination. The oil has a high viscosity index. The
viscosity index is a scale that states the resistance of the oil to flow, ranging from 0 to
100, with 0 as the most likely to change viscosity with variation in temperature. The
properties of the oil as included in its manufacturer's specification sheet are shown in
Table 3.2.
Oil characteristics Values
Kinematic viscosity at 40 degrees (mPas) 60248
Viscosity index 97
Density of oil (g/cm3) 0.886
Table 3.2: Characteristics of high viscosity Shell Tellus oil 68 (MSDS, 2006)
3.1.1.4 Soil mixture ratio and oil content
Bentonite-kaolinite-sand soil mixtures were prepared with varying amounts of bentonite
and kaolinte and the soils were named soils 1, 2, 3, 4 and 5 as shown in Table 3.3.
Generally, oil content was the ratio of mass of oil (g) to mass of uncontaminated soil
(g). Oil volumes of 0, 2, 4, 6 and 8% of 5000cm3 were measured via graduated cylinder
(cm3), it was assumed that, 1g = 1cm3 for water. The oil had a density of 0.886g/cm3,
hence, for example, the oil content when 2% volume of oil was mixed into 5000g for
soil prepared for compaction test was obtained as:
2/100 x 5000 = 100cm3
but, 0.886g = 1cm3 for oil
100cm3 = 100 x 0.886 = 88.6g of oil
63
Oil content (%) = 88.6/5000 x 100 = 1.8%
The same procedure was followed for 4, 6, and 8% volumes of oil. Consequently, the
oil contents were generally represented by 0.0, 1.8, 3.5, 5.3, and 7.1%. However, as a
result of contaminated soil sticking to equipment and containers used for experiment, oil
contents may be slightly higher. The aforementioned sticking of contaminated soil may
be more as the oil content increase in soil. Zheng et al (2014) stated that such technical
challenges exist when performing experiments with oil contaminated soils.
The oil was manually mixed with the dry mass of the soil mixtures before water was
added for carrying out different tests. This is to replicate periods of dry season in some
oil producing countries, for example, in Iran, 85% of the country is arid (Badripoor,
2004). Hence, oil contamination affects the dry soil before rainfall. Researchers often
mix oil into soil by the dry weight of the soil in order to carry out tests with
predetermined oil content in the soil. However, there are cases in which water might
have already been present in the soil before contamination with oil, but such a scenario
has not been investigated in this study. Nevertheless, whether oil was added to the soil
first before addition of water or water was added to the soil first before addition of oil,
the soil will contain the same oil and water contents. Section 4.4.2 is a further
discussion on the aforementioned issue.
Soil Bentonite content (%)
Kaolinite content (%)
Sand content (%)
Oil content (%)
Soil 1 10 30 60
0.0, 1.8, 3.5, 5.3,7.1 Soil 2 15 25 60 Soil 3 20 20 60 Soil 4 25 15 60 Soil 5 30 10 60
Table 3.3: Soil mixtures with different oil content chosen for the present study
64
Typical aggregate size distribution curves of the uncontaminated soil mixtures and sand
are shown in Figure 3.2. The curves were obtained by dry sieving of oven dried soils.
Figure 3.2: Aggregate size distribution curve of uncontaminated soil mixtures and sand
The aggregate size distribution of contaminated soil mixtures are shown in Chapter 4
and Appendix A5.
3.2 Significance of tests
The tests presented in this chapter include the grading modulus using particle size
analysis test (dry sieving method), Atterberg limit tests (liquid limit and plastic limit),
compaction and hydraulic conductivity.
3.2.1 Grading modulus using aggregate size distribution
SAPEM (2011) defined aggregate as a composition of soils that can be separated by
mechanical means and stated that the aggregate is passed through a set of sieves and the
65
ratio of the sum of percentage of mass of soil retained on 2, 0.425 and 0.075mm sieves
to 100 is the grading modulus.
Grading modulus is an assessment of the reduction of fine aggregates in a soil. It is
calculated as shown in equation 3.1.
GM = (P2 + P0.425 + P0.075)/100 (3.1)
where GM = grading modulus; P2 = percentage of the soil retained on 2mm sieve; P0.425
= percentage of the soil retained on 0.425mm sieve; P0.075 = percentage of the soil
retained on 0.075mm sieve.
The more the percentage of soil aggregates retained on the 2, 0.425 and 0.075mm
sieves, the higher the grading modulus of the soils. Generally, soils with higher
proportion of larger grain sizes have higher grading modulus (SAPEM, 2011).
However, due to clay and sand adhering to each other, and soil aggregates clogging
sieve aperture, grading modulus is not a satisfactory assessment for design (Somayajulu
and Anderson, 1971). Hence, it is not definitive that soils with higher proportion of
larger grain sized particles would have higher grading modulus.
The procedure of carrying out the test is described in section 3.5.1. The test confirms
reduction of fine aggregates in a soil. Although the grading modulus is not a true
representation of gradation of soil, it is an important test to confirm if oil contamination
reduced the fine aggregate in the experimental soils. The test is important as it shows
the effect of oil on contaminated soils without water. Grading modulus test results are
shown in Appendix A6.
66
3.2.2 Atterberg limits
The liquid limit is the minimum water content at which the soil behaves like a liquid
while the plastic limit is the minimum water content at which the soil exhibits a plastic
state, as the soil changes from plastic to semi-solid state. The plasticity index is the
difference between the liquid limit and the plastic limit. The Atterberg limits are
relevant because they are used for plasticity characterization of the soil. They show if
the plasticity of the soil increase or decrease as that affects the behaviour of the soil.
Appropriate amount of water was added to the contaminated soils to carry out the liquid
limit tests as stated in section 3.3.2.
When oven drying soil to determine water content for liquid limit and plastic limit, there
may be oil loss due to evaporation. According to Khosravi et al (2013), oil loss in
percentage for their study was less than 3% of the mass of oil in the soil. Hence, the oil
loss was considered insignificant. Appendix B1 showed the Atterberg limts results for
this study. There was insignificant oil loss in this study (Appendix B2).
The oil content was the ratio of mass of oil (g) to that of mass of uncontaminated soil
(g). However, oil contents may be higher because of contaminated soil sticking to
container used in mixing the soil with oil.
oc = Mo/Msoil x 100 (3.2)
where oc = oil content (%); Mo = Mass of oil (g); Msoil = mass of uncontaminated soil
(g).
67
The oil loss (%) was the ratio of mass oil loss (g) to the mass of dry contaminated soil
(g). The dry contaminated soil contained soil solids and oil residue (Tong, 2008; Zheng
et al, 2014). They stated that it was necessary to add the mass of oil residue to the mass
of soil solids because when oil evaporated, there was residue left in the dry soil. This
was considered as part of the technical issues when performing experiments with soils
that contained oil.
OL = Mols/(Msolids + Moilr) x 100 (3.3)
where OL = oil loss (%); Mols = mass of oil loss (g); Msolids = mass of soil solids (g);
Moilr = mass of oil residue (g).
The oil loss (g) per mass of oil (g) was expressed in percentage (Table B2.6), this was
less than 5% in majority of the soils.
Table B2.1 showed, for example, that in the case of 1.8% oil content, oil loss (g) and
mass of dry soil were 0.01g and 12.66g respectively. The oil loss (%) = 0.01/12.66 x
100 = 0.08%. The oil loss in (g) per mass of oil (g), expressed in percentage for the
same soil was 0.01/0.23 x 100 = 4.3% (Table B2.6). The same procedure was followed
for other soils and the values are shown in Table B2.1 to B2.6.
3.2.3 Compaction
The purpose of compaction was to investigate the dry density and water content/total
fluid content relationships for oil contaminated soils.
68
3.2.4 Hydraulic conductivity
The purpose of the test was to evaluate differences in hydraulic conductivity of the
uncontaminated and contaminated soils. The soil was compacted in order to produce a
specimen with low hydraulic conductivity, because it was required for a soil to be used
as liner for landfill to have low hydraulic conductivity of less than 1 x 10-9m/s (Nwaiwu
et al, 2009).
3.3 Specimen preparation
The oil contaminated soils for different tests were sealed in containers and kept for one
week to reach equilibrium.
3. 3.1 Specimen for the grading modulus test
200g of soil mixture was used for the uncontaminated soil. The ratio of bentonite,
kaolinite, sand and oil content in each soil mixture was shown in Table 3.3. In the case
of the contaminated soil, mass of contaminated soil used was calculated; for example,
1.8% oil content as:
Mass of uncontaminated soil = 200g.
1g = 1cm3, for oil measured using graduated cylinder (cm3).
2/100 x 200 = 4g
But, density of oil = 0.886
Mass of oil = 0.886 x 4 = 3.5g
69
Mass of contaminated soil placed in top sieve for test = 200 + 3.5 = 203.5g.
The same procedure was followed in the calculation of mass of contaminated soil
placed in the sieve for grading modulus test, with oil contents of 3.5, 5.3, and 7.1%;
mass obtained were 207.1g, 210.6g and 214.2g respectively. There was loss of soils due
to contaminated soils sticking to containers, in which the soils were mixed with oil.
When uncontaminated soils are sieved, the mass retained may be lower than the initial
mass of soil used, due to soil loss (Fratta et al, 2007). Hence, the mass of soil retained in
this study were lower than the initial mass used for the tests (Appendix A5).
The test was carried out as stated in section 3.5.1 by the dry sieving method. However,
the contaminated soils contained oil before sieving, hence, oil contaminated soil
aggregates were sieved.
3.3.2 Specimen for the Atterberg limit test
Sand was sieved through 0.425mm sieve, then, an appropriate mass of sand was
manually mixed with the appropriate mass of bentonite and kaolinite. 250g of soil
mixture was contaminated with the appropriate oil content. Appropriate amount of
water was added to the contaminated soil and mixed thoroughly to form a thick
homogenous paste. The paste was kept for 24 hours in a sealed container before
carrying out the Atterberg limits test. 20g was separated and used for the plastic limit
test. The ratio of the soils and oil in the mixtures was stated in Table 3.3 and the same
procedure was used for all soils. The Casagrande's apparatus was used for the liquid
limit test while while plastic limit test was done by the hand rolling of soil.
Generally, liquid limit tests are done using cone penetrometer or Casagrande cup. Both
apparatus are reliable for the testing of soils, however, the cone penetrometer gives
70
slightly lower values when liquid limits are higher than 100% (Head and Epps, 1980).
Hence, this study used the Casagrande cup as it was an acceptable method for testing.
3.3.3 Specimen for the compaction test
5000g of oven dried soil mixture was contaminated with oil and separated for each test.
A known amount of water was added and manually mixed into the contaminated soil.
The soil mixture that contained oil and water was kept in a container for 24 hours. The
compaction test for each soil mixture was carried out as stated in section 3.5.3. Known
water contents were measured incrementally and added into the soil.
3.3.4 Specimen for the hydraulic conductivity test
The optimum water content for a particular soil was added to its soil mixture, then
mixed thoroughly and compacted in three layers. The optimum water content is the
water content at which the maximum dry density of a soil is attained (Fratta et al, 2007).
Section 3.5.3 explains procedures for compaction of soil and shows typical compaction
curves. The hydraulic conductivity test was done on uncontaminated and contaminated
soils for the five soil mixtures as shown in Table 3.3. Section 3.5.4 explains procedures
for carrying out the test.
3.4 Equipment for experimental testing
The grading modulus tests were done using sieves of different sizes. Liquid limit test
was done using the Casagrande apparatus while plastic limit test was done by the hand
rolling of soil. Compaction test was done with a compaction machine and mould while
hydraulic conductivity test was done with a Rowe cell. The compaction equipment used
71
was manufactured by Newman Industries Limited, Bristol, England while the Rowe cell
was manufactured by Armfield Engineering Limited, Hampshire, England.
A pressure system for confining pressure and two combined digital back pressure input
and quantity of flow reading equipment manufactured by GDS, United Kingdom, was
used along with the Rowe cell (see section 3.5.4).
3.5 Experimental procedures and typical test result
3.5.1 Procedure for the grading modulus test
SAPEM (2011) stated that soil aggregates are sieved in order to obtain the grading
modulus. The soil was prepared as stated in section 3.3.1. The soils used for this study
were oven dried and contaminated with oil, based on the fact that contaminated soils
formed aggregate. The soil aggregates were sieved through 2, 0.425, 0.3, 0.25, 0.212,
0.18, 0.15, 0.125, 0.18, 0.15, 0.125, 0.106, 0.09, 0.075 and 0.063mm sieves. The 0.25,
0.18, 0.15, 0.125, 0.106 and 0.09mm sieves are not BS 1377: 1990 sieves. The grading
modulus was calculated using equation 3.1 as shown in section 3.2.1.
Typical aggregate size distribution curves are shown in Figure 3.3. The oil contents in
the soil were 0.0, 1.8, 3.5, 5.3 and 7.1% and aggregate size distribution curves shifted
from finer to coarser as the oil content increased as shown in Figure 3.3. This showed
that the fine aggregate in soil decreased as the oil content increased.
72
Figure 3.3: Aggregate size distribution curve of uncontaminated and contaminated
soil 1.
The shifting of the aggregate size distribution curve from finer to coarser as oil
contamination increased indicated that larger soil clods were formed in the soil as the oil
contamination increased. Hence, generally, higher percentages of mass of soil clods
were retained on the 2, 0.425 and 0.075mm sieves used for the grading modulus test
(Appendix A6).
3.5.2 Procedure for the Atterberg limits test
Liquid limit test was done using Casagrande method while plastic limit test was done by
hand rolling of soil (BS 1377:1990). In order to perform the liquid limit test for a
particular soil, appropriate amounts of water were added to the contaminated soils and
thoroughly mixed. Appropriate amount of soil was placed in a Casagrande cup, a
groove cut through the soil; then, the crank handle of equipment turned at two
revolutions per second. The cup lifts and drops, and groove closed along a distance of
13mm, with two parts of soil in contact at the bottom of the groove. The number of
73
bumps was recorded. The number of bumps at which the groove closed varied as the
soil was mixed with more water. This was performed for number of bumps within 10
and 50, by remixing the soil taken out from the Casagrande cup with wet soil on glass
plate and remixing with more water. Two bump counts were on each side of 25 bumps.
Wet soil was taken from the zone where the two portions of soil divided by cutting of
the groove had flowed together, via a spatula. The wet soil was placed in a container
and water contents were measured by oven drying of soils. The water content for the
plastic limit test was determined by oven drying soil that crumbled at 3mm diameter,
via the hand rolling method.
The fall cone test is the preferred test for liquid limit tests; however, it is unreliable for
use with clays that possess expansive properties. This study was done using soils with
expansive characteristics as a result of the bentonite content; hence, the Casagrande cup
was used as recommended by Gronbech et al (2011).
The water contents of the contaminated and uncontaminated soils defined the Atterberg
limits of the soils. The formulae used for calculating the water contents in the
uncontaminated and contaminated soils agreed with Tong (2008) and Zheng et al
(2014). It is shown below:
Uncontaminated soil
wu = Mw/ Md x 100 (3.4)
where wu = water content of uncontaminated soil (%); Mw = mass of loss of water (g);
Md = Mass of dry soil (g).
74
Oil contaminated soil
Wo = [(Mt - Mr) - Mv] )/(Ms + Mor) x 100 (3.5)
= [(Mt - Mr) - Mv] / Mr x 100 (3.6)
where wo = water content of oil contaminated soil (%); Mt = mass of wet contaminated
soil (g); Mr = Ms + Mor = mass of dried contaminated soil (g); Mv = mass of loss of oil
(g); Ms = mass of dried soil without oil and water (g); Mor = mass of oil residue (g).
The loss of oil (Mv) was considered insignificant for this study, hence, water content
(%) of oil contaminated soil will be:
= (Mt - Mr) / Mr x 100 (3.7)
Typical variation of water content with the number of bumps is shown in Figure 3.4.
The liquid limit is the water content corresponding to 25 number of bumps. The liquid
limit of the soil in Figure 3.4 is 48%.
Figure 3.4: Liquid limit of uncontaminated soil 1.
A typical plastic limit test result is shown in Table 3.4.
75
Test number 1 2
Mass of wet soil (g) 7.90 14.38
Mass of dry soil (g) 7.00 12.74
Water loss (g) 0.90 1.64
Water content (%) 12.85 12.87 Plastic limit (average) 12.86
Plastic limit 13
Table 3.4: Plastic limit of uncontaminated soil 1
The plastic limit of the soil in Table 3.4 is 13.
The results of the test are explained in Chapter 4, and the liquid limit and plastic limit of
the soils are shown in Appendix B.
When the soil was contaminated with oil, the sum of the oil content and liquid limit or
plastic limit was the total fluid content at Atterberg limits while the sum of oil content
and plasticity index was the total fluid content at plasticity index as shown in Figure 4.5
in Chapter 4 and Table B3 to B4 of Appendix B.
3.5.3 Procedure for the compaction test
Compaction was done following the British Standard light compaction test as outlined
in BS 1377:1990, using 2500g rammer with 50mm diameter of face at a drop of
300mm. The compaction mould had a diameter of 105mm and length of 115.5mm, with
volume of 1000cm3 . Appropriate amount of soil was taken from the soil mixture
prepared for the test as stated in section 3.3.3 and compacted in three layers in a mould
with extension collar for one compaction test; each layer received 27 blows. The soil
was compacted in three layers for thorough densification, however, soils compacted in
more than three layers have more densification. Great care was taken to transfer the soil
76
from its container into the mould fitted with an extension collar for each compaction
and vice versa, so that soil loss was avoided. The extension collar was removed at the
end of the compaction procedure and the soil was trimmed to the top level of the mould.
The soil, mould and base were weighed. Bulk density (ρ) from each compaction test
was calculated as:
ρ = (MSMB – MMB)/V (3.8)
Where, MSMB = mass of the soil, mould and base; MMB = mass of the mould and base;
V= volume of the mould.
The soil was removed from the mould using an extruder, then broken and remixed
manually with the remainder of the prepared sample. Known increment of water was
added manually to the remixed soil and the above mentioned compaction procedure was
repeated. The procedure was repeated until five compactions were carried out. The ratio
of the sum of mass of water increment added and the mass of water in the soil to the
mass of soil was the water content for a compaction.
The formulae used in calculating the dry density for the uncontaminated and
contaminated soils are shown below:
Uncontaminated soil
M = Msl + Mwt (3.9)
ρ = M/V = (Msl + Mwt)/V (3.10)
Mwt = wMsl (3.11)
where M = total mass of compaction mould content; Msl = Mass of solids;
Mwt = mass of water; ρ = bulk density; w = water content.
77
Substituting Mwt = wMsl into equation 3.10.
ρ = (Msl + wMsl)/V (3.12)
ρ = Msl (1+ w)/V (3.13)
However, Msl/V = ρd = dry density
ρ = ρd (1+ w) (3.14)
ρd = ρ/ (1+ w) (3.15)
Oil contaminated soil
M = Msl + Mwt + Mo (3.16)
M = Msl + wMsl + ocMsl
(3.17)
M = Msl (1 + w + oc) (3.18)
Msl = M/(1 + w + oc) (3.19)
where Mo = mass of oil; oc = oil content.
But, ρd = Msl/V (3.20)
ρd = M/[V(1 + w + oc)] (3.21)
ρd = ρ/(1 + w + oc) (3.22)
Typical variation of dry density and water content of soils are shown in Figure 3.5 with
the dry density and water content corresponding to the peak of each compaction curve
as the maximum dry density and optimum water content respectively. The compaction
curves are shown in Chapter 4 and results in Appendix C. Furthermore, variation of dry
density with total fluid content and results are also shown in Chapter 4 and Appendix C
respectively. The total fluid content corresponding to the peak of each compaction curve
is the optimum total fluid content. Typical compaction curves using variations of dry
density and total fluid content are shown in Figure 3.6.
78
Figure 3.5: Compaction curves of uncontaminated and contaminated soil 1 using water
content.
Figure 3.6: Compaction curves of uncontaminated and contaminated soil 1 using total
fluid content.
Zheng et al (2014) measured the water content of oil contaminated soils. They used
diesel contaminated sand, gasoline contaminated clay and engine oil contaminated sand
79
for analysis. Known mass of oil and water were initially mixed into known mass of soil.
Hence, the initial water and oil contents were known. The results are shown in Table
3.5.
Known oil and water contents were used in this study, the same quantities were used for
calculations. However, soil loss could occur as a result of contaminated soil sticking to
experimental equipment and containers. This could result in higher oil contents and
water contents. Higher oil contents and water contents could result in lower dry
densities (Equation 3.22). Minute higher water contents were observed in the measured
water contents of Zheng et al (2014) in Table 3.5.
Soil Oil
content (%)
Known water content added to
soil (%)
Measured water content (%)
Gasoline contaminated clay
4 2 2.00 4 2 2.01 12 2 2.00 12 10 10.00
Diesel contaminated sand 4 2 2.00 4 10 10.01 12 2 2.02
Engine oil contaminated sand 4 2 2.01 4 10 10.01 12 10 10.02
Table 3.5: Comparison of known water content added to oil contaminated soil and
measured water content (Zheng et al, 2014).
The study of Zheng et al (2014) showed that both known water content and measured
water content could be used for experimental computations. However, in a scenario in
which there is a reduction in measured oil and water contents, the effect would be
higher dry densities (See Equation 3.22).
80
Gardner and Hillel (1962) stated that heated uncontaminated loam soil column with
water content of 45%, which was left uncovered, had water evaporation of 1.6% in 24
hrs. Evaporation rate was achieved by adjusting air circulation and radiant heat energy
via a heat pump. The soil column (7cm diameter and 22cm long) had measured
temperatures of 26.5, 25.8, 25.4 and 25 ⁰C at depths of 2, 5, 10, 15, and 20cm
respectively in the soil. The temperature of the laboratory in which the experiment was
performed was within 24 to 26 ⁰C, with an uncontrolled humidity of 30 to 40%. The
rate of evaporation decreases as the temperature and water content decreases (Terzaghi
et al, 1996).
The wet soils in containers, used in this study were always covered by the lids, and this
minimized water evaporation as suggested by Head and Epps (1980). The soils used
were not heated; Gardner and Hillel (1962) heated the soil for their study. The heating
system of the laboratory was switched off during the period of experimental work, for
minimal water evaporation. Zheng et al (2014) observed that measured water contents
in oil contaminated soil could be lower than known water contents in soils obtained by
adding a known mass of water (g) to a known mass of soil (g). This could be because
prepared specimens in containers were not covered with lids or water was lost by
keeping wet soils close to very hot sources of heat.
3.5.4 Procedure for the hydraulic conductivity test
The hydraulic conductivity test was done in accordance with the procedures by Rowe
and Barden (1966). The set up for hydraulic conductivity test is shown in Figure 3.7.
81
Figure 3.7: Hydraulic conductivity test set up – Rowe cell (vertical flow).
The sample used for each test was taken from soil compacted at its optimum water
content in a 1000cm3 mould (section 3.4.3) via sample ring of 76mm diameter and
30mm height. The sample ring was pushed into the compacted soil from the top of the
soil. Soil around the sample ring was trimmed off. The sample diameter was measured
as D and its height as H by pushing the soil out of sample ring and taking the
measurements using a Vernier caliper. The outlet drain diameter, d was also measured
as 3.8mm.
Filter paper (characteristics was not stated) was placed at the base of the cell, the soil
specimen was placed in the Rowe cell and another filter paper was placed on top of the
specimen. A confining pressure of 50kPa was applied, a pressure difference using back
pressure of 40kPa at inflow and back pressure of 20kPa at outflow was used to
introduce water flow till equilibrium was observed as recommended for tests that
contain swelling soils (Meegoda and Rajapakse, 1993; Chalermyanont and Arrykul,
2005). The pressure difference maintained the flow in the soil (Shapiro et al, 1998). The
water flow was measured by taking the outflow reading when it became constant using
82
a timer. Hence, the flow rate was the measured quantity of flow (interval) per time (see
Appendix E). The input flow was not recorded; it was assumed that hydraulic
conductivity values based on steady outflow were reliable for small soil specimens, as
recommended by Green et al (1998). They used soil specimen of 76mm diameter for
their study. The height of sample was stated as within 60 to 75mm. The study was on
the laboratory outflow measurement for hydraulic conductivity of small soil specimen,
without the recording of input flow.
The readings used for this study were constant; there was no archiving of non-constant
outflow.
The confining pressure 50kPa was applied through a pressure control system via the
confining pressure port of the Rowe cell, by choosing 50kPa as the pressure. The back
pressures of 40kPa and 20kPa that introduced the flow were applied through combined
digital back pressure input and quantity of flow reading equipment. One was connected
to the inflow port of the Rowe cell while the other was connected to the outflow port of
the Rowe cell. The back pressure was introduced by typing the value of back pressure
on the key pad of the equipment. The back pressure was shown on the back pressure
display screen after its input. The volume of water was shown on the volume reading
screen of the equipment (see Fig 3.7).
According to Meegoda and Rajapakse (1993), hydraulic conductivity tests conducted
on clays gave steady state reading within one week. It was observed in this study that
hydraulic conductivity readings were constant within one week.
The hydraulic conductivity was determined using the standard equation for the
experiment:
83
kv = Q/60Ait m/s (3.23)
where Q = volume of water (ml) in time, t (mins); A = Area of sample (mm2), i =
hydraulic gradient (102Δp/H), Δp = pressure difference (kPa) between back pressure at
inflow and back pressure at outflow, H = height of sample (mm), kv = hydraulic
conductivity for vertical flow (m/s).
A typical reading is shown in Table 3.6.
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 0 45154 310 0.31 5 45464 10 45774 15 46084 20 46394 25 46704 30 47014 35 47324 40 47634 45 47944
Table 3.6: Quantity of flow, Q interval (ml) in 5 mins for uncontaminated soil.
* Q interval (mm3) was divided by 1000 to obtain Q interval (ml).
Table 3.5 showed that the quantity of flow (interval) was 0.31 ml in 5 minutes.
The hydraulic conductivity of soils is discussed in Chapter 4 and the results are shown
in Appendix E.
3.6 Summary of Chapter 3
Chapter 3 presented the materials and experimental methods used for this study.
Bentonite-kaolinite-sand mixtures with oil contents of 0.0, 1.8, 3.5, 5.3, and 7.1% were
used for the experiments.
84
The appropriate mass of bentonite, kaolinite and sand were separately oven dried, then,
manually mixed together. Known amounts of oil were mixed into the soil mixtures and
kept in a sealed container for one week to reach equilibrium.
Grading modulus was used for determination of effect of oil on the aggregate size
distribution of the soil mixtures. Liquid limit test was conducted using the Casagrande
cup and plastic limit was done through the hand rolling of soil. Compaction tests were
done using Proctor compaction method and hydraulic conductivity tests were performed
using the Rowe cell.
85
CHAPTER 4
RESULTS AND DISCUSSION
The results of the experimental work are presented and discussed in this Chapter.
4.1 Aggregate size distribution of contaminated soils
The particle size distribution of the bentonite and kaolinite obtained using a hydrometer
and that of sand obtained using a set of sieves was shown in Figure 3.1. Hydrometer test
was not done for oil contaminated sand-clay mixtures because the test cannot be carried
out for soils with organic matter content (Head and Epps, 1980). Oil used in this study
originated from organic matter and contains hydrocarbons.
The aggregate size distribution curves of uncontaminated soil mixtures in Figure 3.2
were different from those of bentonite, kaolinite and sand in Figure 3.1, because soil
aggregates were mixtures of soils, while the particle size distribution curves were for
specific soils (clays and sand).
The aggregate size distribution curve of oven dried uncontaminated soils obtained by
dry sieving in this study generally shifted from coarser to finer as shown in Figure 3.2
because the bentonite content increased in the soil. The bentonite filled pores of
kaolinite and sand and clogged aperture of the sieves as it increased from
uncontaminated soil 1 to soil 5, and when the soils were contaminated by oil, the
aggregate size distribution curve generally shifted from finer to coarser in each soil as
shown in Figure 4.1. This was a result of both bentonite filling the soil pores and oil
contamination forming soil clods.
86
Figure 4.1: Aggregate size distribution of soils
a. Soil 1 b. Soil 2
c. Soil 3 d. Soil 4
e. Soil 5
87
For oil contaminated soils flocculation occurs when oil is added to soils while there is
dispersion of soil aggregates when water is present. Flocculation is the process of
particles adhering to each other and forming clods, in this case as a result of oil
contamination while dispersion is the detaching from each other of solid particles in the
presence of water (Lambe, 1958). Because of oil contamination, the aggregate size
distribution curve shifted from finer to coarser (Figure 4.1), thereby implying that the
oil contamination caused the soil to flocculate. The shifting of the aggregate size
distribution curve further to the coarser in each of the five soils (Figure 4.1) as oil
contamination increased from 0.0% to 7.1% indicated that as oil content increased in
each soil, soil aggregation also increased; hence, the oil glued together more of the fine
aggregate as the oil content increased in the soil. The shifting of the aggregate size
distribution curve of soil from finer to coarser as oil content increased in the soil was
also observed by Ijimdiya (2012), when lateritic soil was contaminated with oil.
The behaviour of the soil as shown on the aggregate size distribution curves laid an
important foundation for other tests such as Atterberg limits, compaction and hydraulic
conductivity. It showed that when oil comes in contact with dry soil, the first effect it
had on it was flocculation. Ijimdiya (2012) stated that when oil was mixed into dry soil,
there was formation of soil clods. This study did not investigate the effect of oil
contamination on the aggregate size distribution of soil that contains water. However,
the presence of water results in dispersion of soil aggregates, consequently, it is
suggestive that the aggregate size distribution curve would shift from coarser to finer.
The contaminated soil aggregates could be deflocculated when water is introduced and
when that happens, the soil is dispersing. The flocculation and dispersion affect the
88
behaviour of the contaminated soil. The effect is explained in sections 4.3, 4.4 and 4.7
on Atterberg limits, compaction and hydraulic conductivity. .
4.2 Grading modulus of oil contaminated soils
Oil contaminated soil clods are different sized soil aggregates formed by the presence of
oil in the soil. The soil clods retained on soil 1 with 7.1% oil content is shown in Figure
4.2. Generally, larger sized clods were formed as the oil content increased in each soil
(Appendix A6). Consequently, in general, there was an increase in the grading modulus
of each soil (Figure 4.2). The amount of larger clods formed by oil contamination was
mainly retained on the 2mm and 0.425mm sieves (Appendix A6).
Figure 4.2: Soil clods on (a ) 2mm sieve (b) 0.425mm sieve for soil 1 (7.1% oil
content).
Assessing the grading modulus by using the formulae [(P2 + P0.425 + P0.075)/100, soils
that contain a high proportion of fine aggregate have a grading modulus below 2.0. In
the context of grading modulus, fine aggregate are soil aggregates with sizes less than
4.75mm while coarse aggregate are soil aggregates with sizes above 4.75mm
(a) (b)
89
(Wieffering and Fourie, 2009). Figure 4.3 and Table A6.6 show the grading modulus of
the soils used for this research.
Figure 4.3: Grading modulus of oil contaminated soils.
The grading modulus of soil 1 ranged from 0.05 to 0.42, soil 2 ranged from 0.14 to 0.36,
soil 3 ranged from 0.08 to 0.47 and soil 4 ranged from 0.02 to 0.67, hence, even with oil
contamination that reduced the fine aggregate, the grading modulus of soils 1, 2, 3 and 4
were below 2.0. This was consistent with the nature of the soils used for the test, a
mixture of sand, kaolinite and bentonite that constituted the fine aggregate. It was also
deduced from Figure 4.3 that soil 4 had the least grading modulus at some points,
followed by soil 3, 2 and 1. However, for soil 5 there was more formation of soil clods
on the 2mm and 0.425mm sieves due to more reduction of fine aggregate, hence its
grading modulus values became high but still below 2.0 (SAPEM, 2011) .
The soils in this research had grading modulus below 2.0, hence, the soils are likely to
be good materials for use as soil liners for landfills, although grading modulus is not a
reliable parameter for design and does not give satisfactory results with regard to the
90
properties of the soil as it is not a true representation of the gradation of the soil
(Somayajulu and Anderson, 1971), and properties of soils influence their behaviour.
Soils with grading modulus below 2.0 are considered as soils of poor quality for road
construction because they possess low strength (SAPEM, 2011). It was deduced that the
soils used for this study are not good for road construction as they had grading modulus
below 2.0.
This study agreed with the findings of Somayajulu and Anderson (1971) that soils with
more fine grained sized particles do not always have lesser grading modulus. They
reported that sand-cement mixtures with 0, 6, 8 and 10% cement content had the same
grading modulus. However, Paige-Green (1999) reported that soils with 63% gravel,
22% sand, 8% silt and clay; 47% gravel, 39% sand, 8% silt and clay; and 32% gravel,
54% sand, and 8% silt and clay had grading modulus of 2.50 , 2.13, and 2.07
respectively. The aforementioned studies used dry soils while the present study was
done with oil contaminated soils, however, the soil aggregates were fine aggregates
(less than 4.75mm aggregate sizes) in all studies. Grading modulus data are interpreted
cautiously to avoid erroneous conclusions (Somayajulu and Anderson, 1971). This is
recommended for interpretation of grading modulus data of this study.
4.3 Plasticity characteristics of oil contaminated soils
The liquid limit and the plastic limit tests were done for the present study. Liquid limit
and plastic limit were defined in section 3.2.2. The range of the liquid limit and plastic
limits of uncontaminated montmorillonites and kaolintes, as stated by Fratta et al (2007)
are shown in Table 4.1. The liquid limit and plastic limit of Wyoming sodium bentonite
and China clay used for this study are shown in Table 4.1 and Appendix B.
91
Soil minerals and clay soils Liquid limit (%)
Plastic limit (%)
Montmorillonites 100 - 800 50 - 100 Kaolinites 35 - 100 25 -35 Wyoming sodium bentonite 540 66 China clay 61 32
Table 4.1 Liquid limit and plastic limit of soil minerals and clay soils of study.
The Atterberg limits and plasticity index of the soils of this study are shown in Figure
4.4 while the total fluid content at the Atterberg limits and plasticity index are shown in
Figure 4.5.
Figure 4.4: Atterberg limits and plasticity index of soils
92
Figure 4.5: Total fluid content at Atterberg limits and plasticity index of soils
Das (2010) stated that water molecule has a negative charge at one end and a positive
charge at the other end, an arrangement referred to as dipole while plate shaped clay
particles possess a negatively charged surface. The cations (positive charges) of water
are attracted to the negatively charged clay surface, hence, by force of attraction, water
is held to clay particle, known as double layer water, and the innermost layer of the
double layer water is adsorbed by the clay. Generally, bentonites are described as clays
with negatively charged surfaces, which are attracted to the positive charges of water. In
the case of kaolinites with zero net charge, water is adsorbed by individual particles of
the soil (Al-Rawas and Goosen, 2006).
There was soil aggregation when the soils were contaminated by oil, as proved by the
aggregate size distribution tests of the contaminated soils, but, when water was added
during the liquid limit test, the soil dispersed and more of the soil surface was in contact
with water. The increase of water content for the contaminated soil to flow caused an
increase in the liquid limit of the soil, and this was precisely what was observed for soils
93
1, 2, 3, 4 and 5. The soils with higher bentonite content generally required more water
for their dispersion and flow; hence, they had higher liquid limits.
Wilbourn et al (2007) carried out Atterberg limits tests on uncontaminated sand-
bentonite-kaolinite mixtures, they added sand and kaolinite to bentonite and there was a
reduction in Atterberg limits. The bentonite-kaolinite-sand ratios they used were
bentonite 10%, kaolinite 40%, sand 50% (soil A); bentonite 15%, kaolinite 35%, sand
50% (soil B); bentonite 20%, kaolinite 30% and sand 50% (soil C). This study had
lower Atterberg limits for uncontaminated soils 1, 2 and 3 in comparison with that of
Wilbourn et al (2007) due to the higher percentage of sand in the soil ratios, however,
they were close to that of Spagnoli and Sridharan (2012) as their uncontaminated sand-
clay mixtures contained quartz powder that increased the liquid limits of the soils.
The plasticity of the soils in this study ranged from high to very high. Burmister (1949)
classified soils using the plasticity index as non plastic (0%), slightly plastic (0 - 5%),
low plasticity (5- 10%), medium plasticity (10 - 20%), high plasticity (20 - 40%) and
very high plasticity (> 40%). Soil 5 contained the highest amount of bentonite,
consequently, its liquid limits and plastic limits were the highest, next was soil 4, then
soils 3, 2 and 1. The Atterberg limits of the soils were increased because bentonite and
oil contents in the soils influenced the characteristics of the soils. Rehman et al (2011)
stated that when oil gives extra cohesion to a soil, the liquid limit increases. The soils
also had increased plastic limits that resulted in increased plasticity index for the soils.
The five soils had liquid limits that were more than 20% and their plasticity index were
more than 7%. Ige (2010) specified those limits for soils to be used as soil liners.
Atterberg limits are determined and qualitative interpretations are done, however, it is
94
difficult to establish and interprete a quantitative relationship between Atterberg limits
and composition of the soils, as soils could possess the same liquid limit or plastic
limit and exhibit varying behaviours.
The plasticity of the oil contaminated soils increased as confirmed by addition of more
water to soils that contain more oil for the soils to flow. Rehman et al (2007) stated that
when more water was added to high plasticity clay that was contaminated by oil, there
was a change in the Atterberg limits of the soil. The soils of this study could flow when
dispersed by water, and the liquid limits increased, hence, in spite of the formation of
clods as oil comes in contact with soils, the permeation of water through soils in the
presence of oil could result in elevated liquid limits as the oil imparts cohesion to the
soils. The presence of bentonite and kaolinite had imparted a plastic behaviour to the
soil; when contaminated with oil and water added, the result was an oily soil with
increased liquid limit. Oil contamination lubricated the soil, and its interaction with
water resulted in increased liquid limit as more water was required to change the state of
the soil to a flowing mass.
There was an increase in the plasticity index of the soils as the bentonite content
increased because the liquid limit and plastic limit increased. The plasticity index of soil
1 ranged from 35% to 42%. Soil 2 had a plasticity index that ranged from 56% to 60%
while soil 3 had a plasticity index between 67% to 71%. Wilbourn et al (2007) also
reported very high plasticity index because of the presence of bentonite in the soil. Soils
with plasticity index of less than 65% are generally considered suitable as soil liners for
landfills (Ige, 2010). Soils 1 and 2 possessed plasticity index that was less than 65%,
that of soil 3 was close to 65% while those for soils 4 and 5 were beyond the
aforementioned limit.
95
4.4 Compaction of oil contaminated soils
4.4.1 Compaction curves using variation of dry density and water content
The compaction tests were done for soils 1, 2, 3, 4 and 5, the results are shown in
Appendix C while the compaction curves are shown in Figure 4.6. The aim was to
determine how an increase in the oil content affected the maximum dry density and
optimum water content of the soil.
96
Figure 4.6: Compaction of uncontaminated and contaminated soils.
a. Soil 1 b. Soil 2
c. Soil 3 d. Soil 4
e. Soil 5
97
The aggregate size distribution of the soils established that oil caused flocculation. The
soils had different proportion of bentonite and kaolinite and when the flocculated
contaminated soils were compacted, they exhibited different behaviours because at
various levels of oil contamination, the flocculation of the soils differed. Addition of
water to the flocculated soils resulted in dispersion of the clay content in the
contaminated soils, thereby causing a variation in the behaviour of the various oil
contaminated soils from the uncontaminated soil.
Water content affected the oil contaminated soil during compaction; the oil
contaminated soil was more flocculated when water content was low in the soil.
Dispersion increased when more water was added to soils, and at the optimum water
content, the soils had a combination of dispersed and flocculated soil fabric.
The dispersion of the soil from a flocculated soil fabric in each of the soils was
responsible for the varying maximum dry density of the soils, as each soil had a
combination of less flocculated and water dispersed soil content at its optimum water
content. This behaviour of the soil mix actually agreed with Lambe (1958) who also
found that both dispersion and flocculation could occur during compaction.
The contaminated soils with more oil content had lower optimum water content because
soil pores already contained more oil. The higher the oil contents in the soil, the lower
the water content that would be deflocculating the contaminated soil to attain the
maximum dry density. The soil was a combination of a flocculated and dispersed soil at
the optimum water content, hence, it was deduced that as the oil content increased in
each soil, the water content that produced a combination of dispersed and flocculated
soil at which the optimum water content was attained was lower.
98
Generally, as the bentonite content increased from soil 1 to soil 5, the maximum dry
density reduced. The uncontaminated soils with a lower content of bentonite were
dispersed faster than the soils with more bentonite content. Furthermore, generally, the
uncontaminated soils with higher bentonite content had higher optimum water content
and lower maximum dry density. This showed that as the bentonite content increased in
the soils from uncontaminated soil 1 to soil 5, there was an increase in the absorption of
water by the bentonite, also as kaolinite content decreased in the soil, there was a
decreasing hydrous nature of the kaolinite. This resulted in a decreased maximum dry
density in soils of higher bentonite content.
Chalermyanont and Arrykul (2005) reported that as bentonite content increased in
uncontaminated sand-bentonite mixtures, maximum dry density reduced; however
Jawad (2014) reported an increase in the maximum dry density as the bentonite content
increased in uncontaminated sand-bentonite mixtures. Wilbourn et al (2007) used
uncontaminated soil A (bentonite 10%, kaolinite 40%, sand 50%); soil B (bentonite
15%, kaolinite 35%, sand 50%) and soil C (bentonite 20%, kaolinite 30%, sand 50%),
soil B had highest maximum dry density, while in this research uncontaminated soil 2
had highest maximum dry density. Soil A had the lowest maximum dry density in their
study while in this study uncontaminated soils 3, 4 and soil 5 had the lowest maximum
dry density because the high bentonite content resulted in reduction of the maximum
dry density of the uncontaminated soil. Kenney et al (1992) stated that bentonite content
of about 20% in uncontaminated sand-bentonite mixtures resulted in a reduction of
maximum dry density. Soils 3, 4 and 5 with bentonite content of 20%, 25% and 30%
had lower maximum dry density than soils 1 and 2.
99
Soil 1 (Figure 4.6) with lowest bentonite content (10%) had maximum dry density that
generally reduced because of increasing oil content. Soil 1 had more porosity than other
soils because it contained the smallest amount of bentonite; addition of oil filled these
pores, consequently, the maximum dry density reduced. Bentonite and kaolinite filled
the pore spaces of the sand in this study, that resulted in reduced maximum dry density
and optimum water content as the soil was compacted at increased levels of oil
contamination.
Al-Rawas et al (2005) stated that a soil had reduced dry density because oil filled the
voids of the soil. Soils 2, 3, 4 and 5 in this research had a decrease in dry density as oil
content increased because oil lubricated the soil by filling voids. It could be suggested
that although bentonite and kaolinite filled the pores of sand, oil also infiltrated into the
pores, thereby lubricating the soil and consequently reducing the maximum dry density
accompanied by a reduction of the water content. Al-Sanad et al (1995) stated that oil
content decreased maximum dry density of well graded sand. Khamehchiyan et al
(2007) stated that oil lubrication decreased maximum dry density, as oil content
increased in low plasticity clay and sand with 5 to 15% silt, accompanied by a reduction
in the water content. They stated that when oil reduces the contact of soil particles and
water, the capillary tension force reduces as oil content increases and this result in a
decrease of the maximum dry density of the soil.
The reduction of optimum water content as oil content increased in soils means that oil
does not have a water absorbing nature. The nature of oil in terms of water absorption is
in contrast to that of cement. Al-Rawas et al (2005) stated that increase in cement
content decreased maximum dry density as optimum water content increased because of
its water absorbing nature. Okafor and Okonkwo (2009) discovered that rice husk ash
100
reduced maximum dry density of lateritic soil as optimum water content increased, as it
reduced fine aggregate of the soil.
Oil and water do not mix, oil is hydrophobic, restricting the contact between particles in
soil and water, this action results in decreased density of the soil. The oil in the
lubricated soil, a soft soil paste, resulted in a decreased maximum dry density as oil
content increased in the soil, accompanied by decreased optimum water content.
Soils 3, 4 and 5 had a decrease in maximum dry density as the oil content was increased
as shown on the compaction curves in Figure 4.6.
Oil contamination of soils resulted in formation of soft oil contaminated clods. When
the contaminated soils were compacted, there was a decrease in the maximum dry
density and optimum water content in the soils. The clods also contained oil in their
voids and compaction of the lubricated soil resulted in decreased maximum dry density.
This agreed with the findings of Al-Rawas et al (2005) that oil in soil voids resulted in a
decrease in maximum dry density.
Addition of water to soils resulted in the clay content in the sand-clay mixture absorbing
water; the oil contaminated soil was a swelled contaminated soil mostly due to bentonite
content and the swelled contaminated soil occupied more space in the compaction
mould. The outcome was a reduction of the maximum dry density of the soil. This
agreed with the findings on the effect of oil contamination on soils by Rahman et al
(2010). It also agrees with the findings of Chalermyanont and Arrykul (2005), that
bentonite in soils could result in a reduction of maximum dry density.
101
The compaction of soils at increasing oil contents resulted in less water used for
compaction to attain the maximum dry density as the oil and water filled the soil pores.
Oil contamination and the presence of water caused separation of soil voids, resulting in
reduced maximum dry density (Al-Rawas et al, 2005).
4.4.2 Compaction curves using variation of dry density and total fluid content
The compaction curves of the soils using variation of dry density with total fluid content
are shown in Figure 4.7. The results are shown in Appendix C. Previous studies used
variation of dry density and water content only.
102
Figure 4.7: Variation of dry density with total fluid content of soils.
a. Soil 1 b. Soil 2
c. Soil 3
d. Soil 4
e. Soil 5
103
Figure 4.7 showed that as optimum total fluid content increased in each soil, the
maximum dry density of the soil decreased. Generally, the compaction curves shifted to
higher optimum total fluid contents because the oil content increased in the soil.
However, it was observed that the compaction curves of soils with 7.1% oil contents in
soil 1 to 4 did not have optimum total fluid contents greater than that of 5.3% because
the soils had very low optimum water contents.
In a scenario in which the soil contained water before oil was added to the soil, the
amount of water in the soil was the water content. Furthermore, the total fluid content
would be the sum of water content and the oil content of the soil. Addition of more
water to the contaminated soil would result in increased water content. Generally, the
uncontaminated soils in each of the five soils of this study had higher optimum water
content and higher maximum dry density. It is suggestive that if soils contained water
before oil was added for the tests, the soils with more water content would have higher
maximum dry density.
According to Daniel (1991), when a clay soil is wet with water, it becomes sticky,
forming soil clods that disperse as the water content increases. This behaviour applied
to the soils of this study, if water was added firstly, before addition of oil. Hence, oil
added to soil containing water will flocculate the soil. Also, oil contamination of a soil
that did not contain water, resulted in flocculation of the soil (Ijimdiya, 2012), and
addition of water to the oil contaminated soil would result in dispersion of the soil. Oil
lubricates a soil that contains water, hence, there is flocculation of soil, but, when the
soil comes firstly in contact with oil, the soil becomes lubricated; hence, addition of
water results in dispersion of the soil.
104
Soils used for compaction test were flocculated when oil was mixed into the soils.
When water content increased in the soil as the compaction test was carried out, the soil
dispersed. There was a combination of flocculated and dispersed soil at the maximum
dry density. Generally, in this study, soils with higher optimum total fluid contents had
lower maximum dry densities. It is suggestive that the combination of flocculated and
dispersed soil at which the maximum dry density is attained is reached faster when the
oil content is higher in the soil. This is in agreement with Lambe (1958) who stated that
dispersion of flocculated clay soil increases as the water content increase when
compaction test is performed. However, this study did not carry out scanning electron
imaging of the soil to observe dispersion and flocculation.
4.4.3 Compaction curves from variation of dry density and total fluid content
using data of some previous researchers.
Data of some previous researchers were used for compaction curves. The compaction
curves of variation of dry density with total fluid content are shown in Figure 4.8 to
4.15. The curves were derived from Figures 2.10 to 2.17. Generally there was an
increase in the maximum dry density as the optimum total fluid content increased in Fig
4.8 while the maximum dry density decreased as the optimum total fluid content
increased in Figure 4.9 to 4.15. Generally, the compaction curves shifted to higher
optimum total fluid contents as a result of increase in oil contents (Appendix C4 and
C5).
105
Figure 4.8: Variation of dry density with total fluid content for metasedimentary soils
(Rahman et al, 2011), from Figure 2.10.
Figure 4.9: Variation of dry density with total fluid content for poorly graded sand
(Al Sanad et al, 1995), from Figure 2.11.
106
Figure 4.10: Variation of dry density with total fluid content for poorly graded sand
(Khamehchiyan et al , 2007), from Figure 2.12.
Figure 4.11: Variation of dry density with total fluid content for sand with 5 to 15% silt
(Khamehchiyan et al , 2007), from Figure 2.13.
107
Figure 4.12: Variation of dry density with total fluid content for low plasticity clay
(Khamehchiyan et al , 2007), from Figure 2.14.
Figure 4.13: Variation of dry density with total fluid content for basaltic grade V soils
(Rahman et al, 2010), from Figure 2.15.
108
Figure 4.14: Variation of dry density with total fluid content for basaltic grade VI soils
(Rahman et al, 2010), from Figure 2.16.
Figure 4.15: Variation of dry density with total fluid content for granitic sandy loam
(Rahman et al, 2011), from Figure 2.17.
109
4.5 Plasticity characteristics and compaction of oil contaminated soil
The liquid limits of soils increased as oil contamination increased because more water
was added to disperse the soils, so that the soils could flow (Figure 4.16). The
compaction of the oil contaminated soil 1 to 5 showed that generally as the oil content
increased in the soil, the optimum water content decreased, accompanied by a reduction
in the maximum dry density. The reduction of the optimum water content of the soil
was because a low content of water was required to produce a dispersed flocculated soil
mixture that gave the maximum dry density. Oil content filled soil pores, hence, a lower
water content than that of the uncontaminated soil was required to fill more of the soil
pores at reduced maximum dry density. Generally, the more the oil content, the less the
water content required to reach the maximum dry density of a soil. However, for the
liquid limit, the soil was dispersed before it could flow and the presence of more oil
required more amount of water for the oil contaminated soil to be dispersed and flow.
The liquid limits and plastic limits increased as oil content increased in the bentonite-
kaolinite-sand mixtures of study as a result of dispersion. Figure 4.16 and Appendix D
show that generally as plasticity characteristics and optimum total fluid content
increased in the soils, the maximum dry density and optimum water content of the soils
decreased.
110
Figure 4.16: Variation of maximum dry density with optimum water content, optimum
total fluid content and plasticity characteristics of soil 1.
a. Soil 1 b. Soil 2
c. Soil 3 d. Soil 4.
e. Soil 5
111
4.6 Hydraulic conductivity of oil contaminated soil
The hydraulic conductivity test was done for soils 1, 2, 3, 4 and 5 and the test was
carried out as described in section 3.5.4.
Hydraulic conductivity of contaminated soil does not involve complex equations
because oil does not mix with water (Silverstein, 1998). The premise that water and oil
were immiscible was used in this study and flow rate was taken as that for water, hence,
in carrying out the test for this study, standard hydraulic conductivity equation was
used.
The variation of hydraulic conductivity with oil content is shown in Figure 4.25 and
results are shown in Appendix E.
Figure 4.17: Variation of hydraulic conductivity with oil content.
112
Generally, the hydraulic conductivities of the soils decreased as the bentonite content
increased from soil 1 to 5. The decrease of the hydraulic conductivity was as a result of
the clay content in the soils. The bentonite content filled soil pores which resulted in
decreased hydraulic conductivity.
The hydraulic conductivity of uncontaminated soil 1 was less than that of
uncontaminated soils used by Ameta and Wayal (2008) and Gueddouda et al (2008) that
reported hydraulic conductivities of sand-bentonite mixture with 10% bentonite as 6.38
x 10-8m/s and dune7 sand-bentonite mixture with 10% bentonite as 1 x 10-7m/s
respectively. The hydraulic conductivities of this study were low in comparison with
that of Rojas et al (2003).
The increase of oil content in the soils of this study resulted in a decrease in hydraulic
conductivity. The oil content filled the pores of the soils and limited the flow of water
through the soils. Each soil had further reduction in hydraulic conductivity as the oil
content increased because the oil content filled the pores of the soils along with the clay.
This study agreed with findings of Shin and Das (2000), Rojas et al (2003) and Chew
and Lee (2006). They stated that the presence of oil in soil results in reduced hydraulic
conductivity because oil filled the pores of the soils.
The type of bentonite used for this study resulted in decrease of hydraulic conductivity.
Wyoming bentonite is a sodium bentonite that has high expansive property, Gueddouda
et al (2008) used calcium bentonite reported a higher hydraulic conductivity as stated
earlier.
7 Dune sand - deposited hill of sand as a result of the movement of wind or water.
113
A criterion for evaluating the performance of soil liner for landfill is its hydraulic
conductivity. Nwaiwu et al (2009) stated that the hydraulic conductivity of soil liners
for landfills should be low (below 1 x 10-9 m/s). Generally, hydraulic conductivity tests
conducted on the samples showed that soils 3, 4 and 5 had hydraulic conductivities that
were close to 1 x 10-9 m/s (see Figure 4.17). The soils met the requirement for use as
soil liners, using hydraulic conductivity as the basis for assessment.
4.7 Plasticity characteristics and hydraulic conductivity of oil contaminated soil
Liquid limit increased in each of the five soils as oil content increased. The hydraulic
conductivity decreased as the liquid limits increased because there was increased
dispersion of the oil contaminated clay content of the soil in the presence of water
(Lambe, 1958). Dispersion of oil contaminated clay soil also resulted in a decrease in
hydraulic conductivity.
Liquid limit and plastic limits generally increased in the soils of this study because of
dispersion of soil in the presence of water. Soil dispersion is mainly caused by the
presence of sodium ions in the soil structure, not in the pore water. The use of sodium
bentonite that contained sodium ions contributed to the high liquid limits and low
hydraulic conductivity of the soils via soil dispersion. In contrast, the presence of
sodium ions in pore water caused an increase in the hydraulic conductivity of soil-
bentonite mixtures (Shariatmadari et al, 2011). Bhuvaneshwari et al (2007) stated that
when clays come in contact with water, dispersion occurs as the force of attraction of
particles within the clay soils is reduced by the presence of water. The effect of
dispersion due to the bentonite and kaolinite in the soils of this study increased liquid
114
limits and reduced hydraulic conductivity, as the bentonite content increased from
uncontaminated soil 1 to 5 and oil content increased in each soil.
Mineralogical content of the soil is a major factor that causes an increase in the
plasticity of a soil, hence, sodium adhering to montmorillonite causes expansion of the
bentonite in soil. The effect of the expansion is increased dispersion of the clay soil;
consequently, the presence of bentonite in the soils caused an increase in the liquid limit
and decrease in the hydraulic conductivity of the soils.
The presence of sodium in the mineralogy of bentonite caused its dispersion (Das,
2010), hence, the dispersed clay content of the soil resulted in increased liquid limits as
bentonite content increased in the soils from soil 1 to soil 5 and decreased hydraulic
conductivity in the soils as the dispersed clay plugged the soil pores.
The dispersed soil plugged the soil pores while the swelling of clay reduced soil pores
in the presence of water and this caused an increase in the liquid limits of the soils as
bentonite content increased from soil 1 to 5 and as oil content increased in each of the
soils.
The characteristics of the soils used in this study were influenced by the presence of
bentonite and kaolinite. Bentonite has a higher specific surface area than kaolinite. The
specific surface area of a soil is the total surface area of a soil per unit mass of the soil.
Liquid limits of the soils increased because there was much absorption of water, as a
large surface area of the clay soil was in contact with water. Furthermore, as more water
was added to the soil, the clay absorbed water, resulting in an increased liquid limit of
the soil.
115
The study showed that soils with higher plasticity characteristics had reduced hydraulic
conductivity. Figure 4.18 and Appendix F show that liquid limits of the soils increased
while the hydraulic conductivity decreased as the oil content increased.
116
Figure 4.18: Variation of hydraulic conductivity with plasticity characteristics of soils.
a. Soil 1 b. Soil 2
d. Soil 4 c. Soil 3
e. Soil 5
117
4.8 Compaction characteristics and hydraulic conductivity of oil contaminated soil
Generally, when bentonite content increased in bentonite-sand mixture, the maximum
dry density and hydraulic conductivity reduced, while the optimum water content
increased (Chalermyanont and Arrykul, 2005). Generally, in the present study, the soils
had reduced maximum dry density, accompanied by increased optimum water content
as the bentonite content increased from uncontaminated soil 1 to 5. Furthermore, each
of the soils had reduced maximum dry density as the oil contamination increased,
accompanied by a reduction in the optimum water content.
A result of compaction was reduction of hydraulic conductivity. The addition of water
to the soil dispersed the oil flocculated soil during compaction, however, at the optimum
water content; there was a combination of dispersed and flocculated soil. The optimum
water content was attained at lower water content with increase of oil content in each
soil, because oil also filled the pores of the soil. This influenced the hydraulic
conductivity of the soils, as generally, the soils with lower maximum dry density
containing higher oil contents had lower hydraulic conductivity; hence, hydraulic
conductivity reduced with reduction of maximum dry density as a result of oil content.
This agreed with the observation of Chalermyanont and Arrykul (2005) that soils with
lower maximum dry density had lower hydraulic conductivity.
Hydraulic conductivity reduced because soft soil clods were present in the contaminated
soil. The soft soil clods were soft and easily compressible when the soils were
compacted, resulting in reduced hydraulic conductivity (Benson and Daniel, 1990).
Figure 4.19 and Appendix G show that generally as maximum dry density and optimum
water content decreased in the soils, the hydraulic conductivity decreased.
118
Figure 4.19: Compaction characteristics and hydraulic conductivity of soils.
a. Soil 1 b. Soil 2
c. Soil 3 d. Soil 4
e. Soil 5
119
4.9 Summary of results and discussions
The experimental results shows that the aggregate size distribution curve of oil
contaminated soils 1, 2, 3 4 and 5 shifted from finer to coarser as oil content increased
indicating that oil reduced the fine aggregate of the soil while forming soft oily soil
clods. The low values of grading modulus of soils indicated that they could be used as
soil liners for landfill. The Atterberg limits tests showed that soil 1 and 2 had plasticity
index below 65%, that of soil 3 was close to 65%, while those of soil 4 and 5 were
above the aforementioned limit. Maximum dry density and optimum water content
reduced in the soils as oil content increased while the optimum total fluid content
increased. The hydraulic conductivity of soils reduced as the amount of bentonite
increased from uncontaminated soil 1 to 5. Oil contamination also reduced the hydraulic
conductivity of the soils.
Appendix A to G show the results of this study. However, Table 4.2 is summary of this
study.
Geotechnical properties Soil 1 to 5 Atterberg limits Increased as oil content increased Maximum dry density Decreased as oil content increased Optimum water content Optimum total fluid content Increased as oil content increased Hydraulic conductivity Decreased as oil content increased
Table 4.2 Summary of study.
120
CHAPTER 5
CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE WORK
This research investigated the geotechnical properties of oil contaminated bentonite-
kaolinite-sand mixtures. The study generated data on grading modulus, Atterberg limits,
compaction and hydraulic conductivity. Section 5.1, 5.2, 5.3 and 5.4 are conclusions on
the effect of varied oil content on the geotechnical properties of bentonite-kaolinite-sand
mixtures.
5.1 Grading modulus of oil contaminated soils
The research showed that oil contamination shifted the aggregate size distribution curve
from finer to coarser in all the five soils (Figure 4.1). This implied that oil
contamination decreased the fine aggregate in the soil mixtures by forming soft oily soil
clods. The grading moduli of the five soils were below 2.0, hence, the soils could be
used as soil liners for landfills. However, grading modulus is not a sole criterion, as the
hydraulic conductivity of soil is also considered (Ige, 2010).
5.2 Plasticity characteristics of oil contaminated soils
The Atterberg limits tests showed that oil contamination generally increased the
Atterberg limits of the five soils (Figure 4.4). The increase in bentonite content from
uncontaminated soil 1 to 5 caused an increase in the Atterberg limits of the soils, and
when each soil was contaminated by oil, the Atterberg limits generally increased
because more water was added for the soil to flow as oil content increased. The
plasticity index of the five soils generally increased as oil content increased in each soil.
121
Soils 1 and 2 had plasticity index below 65%, while soil 3 had plasticity index close to
65. Soil 3 is suitable as soil liner for landfill, as Ige (2010) specified that soils with
plasticity index of 65% are suitable as soil liners. There is difficulty in handling soils
with plasticity index above 65 (Ige, 2010).
5.3 Compaction of oil contaminated soils
The compaction tests showed that increase in oil content in each of the soil mixtures
resulted in a reduction of both maximum dry density and optimum water content. The
maximum dry density reduced in the soils due to the swelling nature of bentonite.
Furthermore, oil lubrication reduced the maximum dry density as oil filled the soil
pores. The oil in soil pores reduced the contact of water and soil, resulting in the
reduction of maximum dry density.
5.4 Hydraulic conductivity of oil contaminated soils
The hydraulic conductivity test for the five soils showed that increase in bentonite
content from uncontaminated soil 1 to 5 caused a decrease in the hydraulic conductivity
of the soils. Oil contamination decreased the hydraulic conductivity in each of the five
soils because oil occupied soil pores. The oil used for this research had a very high
viscosity index that contributed to decrease of hydraulic conductivity.
Soil mixtures that have hydraulic conductivity of less than 1 x 10-9 m/s are suitable for
soil liners. Generally, the hydraulic conductivity of soils 3, 4 and 5 were below 1 x 10-9
m/s.
122
5.5 Recommendations for future work
A proper view of the findings of this research showed that there are some areas that will
need further research.
It is recommended that sand and bentonite mixtures be used for further research.
Kaolinite was included because kaolinite reduced the liquid limit of bentonite along
with sand, however, sand-bentonite mixtures are still used as soil liners for landfills,
putting into consideration the cost of clays.
It is recommended that future study use oil of varied viscosities. The oil used for this
research had a viscosity index of 97, which was highly viscous. Oil content of lower
viscosity could be used because crude oil products are of varied viscosity.
123
REFERENCES AKGUN, H. 2010. Geotechnical characterization and performance assessment of
bentonite/sand mixtures for underground waste repository sealing. Applied Clay
Science, 49, 394-399.
AKINWUMI, I., DIWA, D. & OBIANIGWE, N. 2014. Effects of crude oil
contamination on the index properties, strength and permeability of lateritic
clay. International Journal of Applied Sciences and Engineering Research, 3,
816-824.
AL-DUWAISAN, D. B. & AL-NASEEM, A. A. 2011. Characterization of oil
contaminated soil Kuwait oil lakes. In: Proceedings of International Conference
on Environmental Science and Technology, Singapore, 2011. IACSIT Press,
439-442.
AL-RAWAS, A. A. & GOOSEN, M. F. 2006. Expansive soils: recent advances in
characterization and treatment, Taylor & Francis.
AL-RAWAS, A., HASSAN, H. F., TAHA, R., HAGO, A., AL-SHANDOUDI, B. &
AL-SULEIMANI, Y. 2005. Stabilization of oil contaminated soils using cement
and cement by-pass dust. Management of Environmental Quality: An
International Journal, 16, 670-680
AL-SANAD, H. A., EID, W. K. & ISMAEL, N. F. 1995. Geotechnical properties of oil
contaminated Kuwaiti sand. Journal of Geotechnical Engineering, 121, 407-
412.
AMETA, N. & WAYAL, A. S. 2008. Effect of bentonite on permeability of dune sand.
Electronic Journal of Geotechnical Engineering, 13, 1-7.
124
BADRIPOOR, H. 2004. Islamic Republic of Iran. Country pasture/forage resource
profiles. FAO Publications.
BENSON, C. H. & DANIEL, D. E. 1990. Influence of clods on the hydraulic
conductivity of compacted clay. Journal of Geotechnical Engineering, 116,
1231-1248.
BHUVANESHWARI, S., SOUNDRA, B., ROBINSON, R. & GANDHI, S. 2007.
Stabilization and microstructural modification of dispersive clayey soils. In: 1st
International Conference on Soil and Rock Engineering, Srilankan Geotechnical
Society, Columbo, Srilanka, 2007. 1-7.
BRITISH STANDARD, 1377. 1990. ‘Methods of test for soils for civil engineering
purpose.’. British Standards Institution, London.
BURMISTER, D. M. 1949. Principles and techniques of soil identification. In:
Proceedings of the 29th Annual Meeting of the Highway Research Board.
Wasington DC, December 13 - 16, 1949. Transport Research International
Documentation. 29, 402 - 433.
CHALERMYANONT, T. & ARRYKUL, S. 2005. Compacted sand-bentonite mixtures
for hydraulic containment liners. Songklanakarin Journal of Science and
Technology, 27, 313-323.
CHEW, S. & LEE, C. 2006. Simple shear behaviour of palm biodiesel contaminated
soil. Journal of Engineering and Applied Sciences, 5, 12.
DANIEL, D. 1991. Design and construction of RCRA/CERCLA final covers. Soils
Used in Cover Systems, EPA/625/4-91/025.
DAS, B. M. 2010. Principles of geotechnical engineering, Cengage Learning.
125
ERTEN, M. B., GILBERT, R. B., EL MOHTAR, C. S. & REIBLE, D. D. 2011.
Development of a laboratory procedure to evaluate the consolidation potential of
soft contaminated sediments. Geotechnical Testing Journal, 34, 467-475.
EVANS, J. C. 1993. Vertical cutoff walls. Geotechnical practice for waste disposal.
Springer.
FINE, P., GRABER, E. & YARON, B. 1997. Soil interactions with petroleum
hydrocarbons: abiotic processes. Soil Technology, 10, 133-153.
FINGAS, M. 2010. Oil spill science and technology, Gulf professional publishing.
FRATTA, D., AGUETTANT, J. & ROUSSEL-SMITH, L. 2007. Introduction to soil
mechanics laboratory testing, CRC Press Incorporated.
GARDNER, W. & HILLEL, D. 1962. The relation of external evaporative conditions to
the drying of soils. Journal of Geophysical Research, 67, 4319-4325.
GRATCHEV, I., SHOKOUHI, A., INOUE, A. U. & BRENNAN, A. 2012. Feasibility
of using bentonite, lime and fly ash in permeable reactive barriers for acid
sulphate soils. In: 11th Australia New Zealand Conference on Geomechanics,
Australia, 2012. International Society for Rock Mechanics.7-12.
GREEN, T., PAYDAR, Z., CRESSWELL, H. & DRINKWATER, R. 1998. Laboratory
outflow technique for measurement of soil water diffusivity and hydraulic
conductivity, CSIRO Land and Water.
GRONBECH, G. L., NIELSEN, B. N. & IBSEN, L. B. 2011. Comparison of liquid
Limit of highly plastic clay by means of Casagrande and fall cone apparatus.
Age (mil. Years), 40, 46.
126
GUEDDOUDA, M., LAMARA, M., ABOUBAKER, N. & TAIBI, S. 2008. Hydraulic
conductivity and shear strength of dune sand-bentonite mixtures. Electronic
Journal of Geotechnical Engineering, 13, 1-15.
GUPTA, M., SRIVASTAVA, R. & SINGH, A. 2010. Bench scale treatability studies of
contaminated soil using soil washing technique. Journal of Chemistry, 7, 73-80.
HEAD, K. H., & EPPS, R. 1980. Manual of soil laboratory testing, Pentech Press
London.
IGE, O. O. 2010. Assessment of geotechnical properties of migmatite-derived residual
soil from Ilorin, south-western Nigerla, as barrier in sanitary landfills.
Continental Journal of Earth Sciences, 5, 32-41
IJIMDIYA, T. S. 2012. Effect of oil contamination on particle size distribution and
plasticity characteristics of lateritic soil. Advanced Materials Research, 367, 19-
25.
JAWAD, T. A. 2014. Improvement of sandy soil properties by using bentonite. Kufa
journal of Engineering, 1,1.
KENNEY, T., VEEN, W. V., SWALLOW, M. & SUNGAILA, M. 1992. Hydraulic
conductivity of compacted bentonite-sand mixtures. Canadian Geotechnical
Journal, 29, 364-374.
KHAMEHCHIYAN, M., HOSSEIN CHARKHABI, A. & TAJIK, M. 2007. Effects of
crude oil contamination on geotechnical properties of clayey and sandy soils.
Engineering Geology, 89, 220-229.
KHOSRAVI, E., GHASEMZADEH, H., SABOUR, M. R. & YAZDANI, H. 2013.
Geotechnical properties of gas oil contaminated kaolinite. Engineering Geology,
166, 11-16.
127
KOGBARA, R. B. 2008. Ranking agro-technical methods and environmental
parameters in the biodegradation of petroleum-contaminated soils in Nigeria.
Electronic Journal of Biotechnology, 11, 113-125.
LAMBE, T. W. 1958. The structure of compacted clay. Journal of the Soil Mechanics
and Foundations Division, ASCE, 84, 1-34.
MEEGODA, N. J. & RAJAPAKSE, R. A. 1993. Short-term and long-term
permeabilities of contaminated clays. Journal of Environmental Engineering,
119, 725-743.
MOHAMEDZEIN, Y., AL-RAWAS, A. & AL-AGHBARI, M. 2003. Assessment of
sand–clay mixtures for use in landfill liners. In: Proceedings of the
International Conference on Geo-environmental Engineering,Singapore, 2003.
211-218.
MSDS, 2011. China clay. Laguna Clay Company, California, United States of America.
MSDS, 2006. Shell Tellus Oil. Shell International Petroleum Company. PATEL, M. A. 2011. Study of geotechnical properties of black cotton soil
contaminated by castor oil and stabilization of contaminated soil by saw dust.
National Conference on recent trends in Engineering and Technology, BVM
Engineering College, Nagar, Gujarat, India, 13th - 14th May, 2011.
PAIGE-GREEN, P. 1999. A comparative study of the grading coefficient, a new
particle size distribution parameter. Bulletin of Engineering Geology and the
Environment, 57, 215-223.
PUSCH, R. 1992. Use of bentonite for isolation of radioactive waste products. Clay
Miner, 27, 353-361.
128
RAHMAN, Z. A., HAMZAH, U., TAHA, M. R., ITHNAIN, N. S. & AHMAD, N.
2010. Influence of oil contamination on geotechnical properties of basaltic
residual soil. American Journal of Applied Sciences, 7, 954.
RAHMAN, Z., UMAR, H. & AHMAD, N. 2011. Engineering Geological Properties of
Oil-Contaminated Granitic and Metasedimentary Soils. Sains Malaysiana, 40,
293-300.
REHMAN, H., ABDULJAUWAD, S. N. & AKRAM, T. 2007. Geotechnical behavior
of oil-contaminated fine-grained soils. Electronic Journal of Geotechnical
Engineering, 12, 1-12.
ROJAS, J., SALINAS, L. & GARNICA, I. 2003. Influence of the kinematic viscosity of
oil contaminants in the compaction and hydraulic conductivity in certain type of
soils. In: Groundwater Engineering: Recent Advances: Proceedings of the
International Symposium on Groundwater Problems Related to Geo-
environment, Okayama, Japan, 28-30 May, 2003. Taylor & Francis, 373.
ROWE, P. W. & BARDEN, L. 1966. A new consolidation cell. Geotechnique, 16, 162-
170
SAPEM, 2011. South African pavement engineering manual. South African National
Roads Agency Limited, South Africa.
SHAPIRO, A. H., FRIEDMAN, J. & BERGMAN, R. 1988. Pressure Fields and Fluid
Acceleration, Encyclopaedia Britannica Educational Corporation.
SHARIATMADARI, N., SALAMI, M. & FARD, M. K. 2011. Effect of inorganic salt
solutions on some geotechnical properties of soil-bentonite mixtures as barriers.
International Journal of Civil Engineering, 9, 103-110
129
SHIN, E. & DAS, B. 2000. Some physical properties of unsaturated oil-contaminated
sand. Geotechnical Special Publication, 142-152.
SILVERSTEIN, T. P. 1998. The real reason why oil and water don't mix. Journal of
chemical education, 75, 116.
SINGH, S., SRIVASTAVA, R. & JOHN, S. 2008. Settlement characteristics of clayey
soils contaminated with petroleum hydrocarbons. Soil & Sediment
Contamination, 17, 290-300.
SOMAYAJULU, Y.P. & ANDERSON, K. O. 1971. Preliminary report on analysis of
soil cement mixture. Alberta Co- operative Highway Research Programme.
Department of Engineering, The University of Alberta, Edmonton, Alberta.
SPAGNOLI, G. & SRIDHARAN, A. 2012. Liquid limit of mixtures of smectite,
kaolinite and quartz powder with water and NaCl solution. International Journal
of Geotechnical Engineering, 6,117 - 123.
TERZAGHI, K., Peck, RB., & Mesri, G. 1996. Soil mechanics in engineering practice,
John Wiley & Sons.
TONG, L. 2008. Study on water-physical and mechanical properties of oil
contaminated soils. Dissertation, Ocean University of China.
WIEFFERING, N.B., & FOURIE, N.B. 2009. Construction materials, Pearson
Education, South Africa, Limited.
WILBOURN, K., STUDENT, R., & VEMBU, K. 2007. Index Properties and Strength
of Artificial Soil Using the Harvard Miniature Method. Final Report, National
Science Foundation. Houston, TX.
WMA, 2013. Mineral composition of a typical Wyoming bentonite. www.wma-
minelife.com/bent/bentmine/bentprod.htm. (Accessed on 23 December, 2013).
130
ZHENG, X., ZHANG, J., ZHENG, T., LIANG, C. & WANG, H. 2014. A developed
technique for measuring water content in oil-contaminated porous media.
Environmental Earth Sciences, 71, 1349-1356.
131
APPENDIX A
AGGREGATE SIZE DISTRIBUTION AND GRADING MODULUS TESTS RESULTS
A1 Particle size analysis test result of sand
Mass of soil used for sieve analysis = 200g Sieves (mm)
Mass of empty sieve (g)
Mass of sieve and
sand (g)
Mass retained on
sieve (g)
Cumulative passed
(g)
Total percent passed
(%) 2.000 461.2 461.2 0.0 199.9 100
0.425 389.3 393.0 3.7 196.2 98.1 0.300 307.5 370.7 63.2 133.0 66.5 0.250 366.3 431.8 65.5 67.5 33.8 0.212 361.3 378.9 17.6 49.9 25.0 0.180 354.5 389.4 34.9 15.0 7.5 0.150 349.5 354.8 5.3 9.7 4.9 0.125 348.8 351.7 2.9 6.8 3.4 0.106 355.4 358.6 3.2 3.6 1.8 0.090 338.8 340.7 1.9 1.7 0.9 0.075 297.0 297.8 0.8 0.9 0.5 0.063 350.7 351.0 0.3 0.6 0.3 Pan 325.5 326.1 0.6 0 0
Total mass retained on sieve = 199.9
Table: A1 Particle size distribution data for sand.
132
Figure: A1.Coefficient of uniformity and coefficient of curvature for sand.
Cu = D60/D10 = 0.3/0.18 = 1.7
Cu < 3, the sand is uniform sand.
Cc = (D30 )2/D10. D60 = (0.23 x 0.23)/(0.18 x 0.3) = 0.0529/0.054 = 0.98
Cc < 1, the sand is gap graded
A2 Specific gravity of sand
(50ml bottle; 10g of soil used for test)
Specific gravity = D2 - D1/[(D4 - D1) - (D3-D2)]
where D1 = mass of density bottle and stopper; D2 = mass of density bottle, soil and
stopper; D3 = mass of density bottle, soil, water and stopper; D4 = mass of density
bottle, water and stopper.
133
Measurements Density bottle 1 Density bottle 2 Density bottle + Stopper (D1)g 32.008 32.006 Density bottle + soil + Stopper (D2)g 42.008 42.006
Density bottle + soil + water + Stopper (D3)g
88.045 88.043
Density bottle + water + Stopper (D4)g 81.833 81.831
Specific gravity 2.640 2.640 2.64
Table A2 Specific gravity of sand.
A3 Specific gravity of bentonite and kaolinite
A3.1 Specific gravity of bentonite
Measurements Density bottle 1 Density bottle 2
Density bottle + stopper (D1)g 32.008 32.006 Density bottle + soil + stopper (D2)g 42.008 42.006 Density bottle + soil + water + stopper(D3)g
88.063 88.061
Density bottle + water + stopper (D4)g 81.833 81.831 Specific gravity 2.652 2.652
2.65
Table A3.1: Data of specific gravity of bentonite
134
A3.2 Specific gravity of kaolinite
Measurements Density bottle 1 Density bottle 2
Density bottle + stopper (D1)g 32.008 32.006 Density bottle + soil + stopper (D2)g 42.008 42.006
Density bottle + soil + water + Stopper(M3)g
87.988 87.986
Density bottle + water + stopper (D4)g 81.833 81.831 Specific gravity 2.601 2.601
2.60
Table A3.2: Data of specific gravity of kaolinite.
A4 Hydrometer test
A4.1 Calibration parameters Mass of hydrometer = 59.8g
Volume of hydrometer , Vh= 59.8ml
Length between 100 and 900ml on sedimentation cylinder = 276mm
Cross sectional area of hydrometer, A = 2898.6mm2
Test temperature = 25 degrees centigrade
Meniscus correction, Cm = + 0.5
Temperature correction, Mt = +1.0 degrees centigrade
Dispersant correction (evaporating 50ml stock solution), x = 2md= 2 x 1.75 = 3.5
Water density correction (British Standard), Cw = 1.8
Hydrometer reading in dispersant = 0.5mm
Rh = Rh’ + Cm = Rh’ + 0.5
HR = 176 – 2.8 Rh
R = Rh + Mt – x + 1.8 = Rh – 0.7
135
A4.2 Hydrometer test formulae
Cross sectional area of cylinder, A = 800/L x 1000 mm2
Where L = Distance from 100 to 900ml on the sedimentation cylinder
Particle diameter D = 0.005531 √µH/(Gs – 1 )t
Where, D = particle diameter ( mm ); µ= viscosity of water at the temperature used for
test; Gs = the specific gravity of the specimen; t = time at which reading was taken
(min).
Percentage passing , k = Gs/[m(Gs – 1)] x R x 100%
Where Gs = specific gravity of specimen; m = mass of soil after it’s pretreatment;
R = Hydrometer reading that was totally corrected.
A4.3 Calibration correction equations
Figure A4.1: Calibration of hydrometer.
136
Scale mark (g/cm2)
Reading ( Rhr) (mm)
Distance from lowest mark Rh or D (mm)
H = Rh + N (mm)
HR (mm)
1.030 30 14 24 94 1.025 25 28 38 108 1.020 20 40 50 120 1.015 15 54 64 134 1.010 10 68 78 148 1.005 5 81 91 161 1.000 0 96 106 176 0.995 -5 111 121 191
Table 4.1 Calibration data for hydrometer.
N = 10mm, h = 140mm, HR = H + ½ (h - Vh/A)
Where N = distance from the neck of hydrometer to lowest calibration mark; h = length of hydrometer bulb (excluding the stem); HR = effective depth
Figure A4.2: Calibration graph for hydrometer.
Calibration equation: HR = 176 – 2.8Rh
137
A4.4 Hydrometer test (Bentonite)
Specific gravity of specimen = 2.65
Viscosity of water at test temperature (BS 1377:1990) = 0.8909mPaS
Initial dry mass of soil used = 59.38g
Soil dry mass after it was pretreated = 58.88g
Loss due to pretreatment = 0.50g
Pretreatment loss = 0.5/59.38 x 100 = 0.84%
D = 0.005531 √µH/( Gs – 1 )t = 0.005531√0.8909HR/1.65t = 4.064 √HR/t
k = Gs/[m(Gs – 1)] x R x 100% = 2.65/(58.88 x 1.65) x R x 100 = 2.726 x R%
Time elapsed (min)
Hydrometer reading (Rhr)
True reading (Rh)
Effective depth ( HR )
Fully Corrected reading ( R )
Particle diameter (D ) (µm )
Particle diameter (D ) (mm )
Percentage finer than D (% )
0.5 31.5 32 64 31.3 45.92 0.04592 85.3
1 31 31.5 87.8 30.8 38.08 0.03808 84
2 30.5 31 89.2 30.3 27.15 0.02715 82.6
4 30 30.5 90.6 29.8 19.34 0.01934 81.2
8 29.5 30 92 29.3 13.78 0.01378 79.9
15 29 29.5 93.4 28.8 10.16 0.01016 78.6
30 28.5 29 94.8 28.3 7.22 0.00722 77.2
60 27.5 28 97.6 27.3 5.18 0.00518 74.5
120 27 27.5 99 26.8 3.69 0.00369 73.1
240 26.5 27 100.4 26.3 2.63 0.00263 71.7
450 26 26.5 101.8 25.8 1.93 0.00193 70.4
1420 26 26.5 101.8 25.8 1.93 0.00193 70.4
Table A4.2: Data of hydrometer test for bentonite.
138
A4.5 Hydrometer test ( Kaolinite )
Specific gravity of specimen = 2.60
Viscosity of water at test temperature = 0.8909mPaS
Initial dry mass of soil used = 55.00g
Soil dry mass after it was pretreated = 54.50g
Loss due to pretreatment = 0.50g
Pretreatment loss = 0.5/50 x 100 = 1%
D = 0.005531√µH/( Gs – 1 )t = 0.005531√0.8909HR/1.6t = 4.126 √HR/t
k = Gs/[m(Gs – 1)] x R x 100% = 2.6/( 54.5 x 1.6) x R x 100 = 2.981 x R%
Time elapsed (min)
Hydrometer reading (Rhr)
True reading (Rh)
Effective depth ( HR )
Fully Corrected reading ( R )
Particle diameter (D ) (µm )
Particle diameter (D ) (mm )
Percentage finer than D (% )
0.50 31.0 31.5 87.8 30.8 54.23 0.05423 91.8 1.0 31.0 31.5 87.8 30.8 38.33 0.03833 91.8
2.00 30.5 31 89.2 30.3 27.55 0.02755 90.3 4.00 30.0 30.5 90.6 29.8 19.63 0.01963 88.8 8.00 29.5 30.0 92.0 29.3 13.99 0.01399 87.3
15.00 29.0 29.5 93.4 28.8 10.29 0.01029 85.8 30.00 28.5 29.0 94.8 28.3 7.33 0.00733 84.3 60.00 26.5 27.0 100.4 26.3 5.33 0.00533 78.4
120.00 24.5 25.0 99.0 24.3 3.73 0.00373 72.4 240.00 21.5 22.0 106.0 21.3 2.74 0.00274 63.5 420.00 18.5 19.0 114.4 18.3 2.15 0.00215 54.6
1420.00 8.5 9.0 150.8 8.3 1.34 0.00134 24.7
Table A4.3: Data of hydrometer test for kaolinite.
139
A5 Aggregate size distribution test results
A5.1 Soil 1
Mass of soil used for sieve analysis = 200.0g
Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on
sieve (g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.6 498.6 0.0 198.0 100.000 0.425 390.3 399.3 9.0 189.0 95.500 0.300 307.4 407.9 100.5 88.5 44.700 0.250 366.2 424.1 57.9 30.6 15.500 0.212 361.6 365.2 3.6 27.0 13.600 0.180 354.4 372.5 18.1 8.9 4.500 0.150 349.7 351.7 2.0 6.9 3.500 0.125 349.1 350.9 1.8 5.1 2.600 0.106 355.6 357.3 1.7 3.4 1.700 0.090 338.9 340.6 1.7 1.7 0.009 0.075 297.3 297.7 0.4 1.3 0.007 0.063 352.1 352.7 0.6 0.7 0.004 Pan 360.9 361.0 0.7 0.0 0.000
Total mass retained on sieve = 198.0g
Table A5.1: Aggregate size distribution data for soil 1 (0.0% oil content).
Mass of soil used for sieve analysis = 203.5g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.6 506.1 7.5 193.1 96.300 0.425 390.2 414.8 24.6 168.5 84.000 0.300 307.4 371.0 63.6 104.9 52.300 0.250 366.0 434.8 68.6 36.3 18.100 0.212 361.4 367.7 6.3 30.0 15.000 0.180 354.5 374.9 20.4 9.6 4.900 0.150 349.6 351.9 2.3 7.3 3.600 0.125 349.0 350.6 1.6 5.7 2.800 0.106 355.5 357.5 2.0 3.7 1.800 0.090 338.9 340.8 1.9 1.8 0.009 0.075 297.2 297.6 0.4 1.4 0.007 0.063 351.3 351.6 0.3 1.1 0.005 Pan 360.9 362.0 1.1 0.0 0.000
Total mass retained on sieve = 200.6g
Table A5.2: Aggregate size distribution data for soil 1 (1.8% oil content).
140
Mass of soil used for sieve analysis = 207.1g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.6 506.4 7.8 196.6 96.200 0.425 390.2 435.3 45.1 151.5 74.100 0.300 307.3 391.8 84.5 67.0 32.800 0.250 366.0 408.2 42.2 24.8 12.100 0.212 361.4 364.5 3.1 21.7 10.600 0.180 354.5 369.4 14.9 6.8 3.300 0.150 349.6 351.0 1.4 5.4 2.600 0.125 349.0 350.3 1.3 4.1 2.000 0.106 355.5 356.6 1.1 3.0 1.500 0.090 338.9 340.4 1.5 1.5 0.007 0.075 297.1 297.4 0.3 1.2 0.006 0.063 351.3 351.7 0.4 0.8 0.004 Pan 360.9 361.7 0.8 0.0 0.000
Total mass retained on sieve = 204.4g
Table A5.3: Aggregate size distribution data for soil 1 (3.5% oil content).
Mass of soil used for sieve analysis = 210.6g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.5 505.3 6.8 201.0 96.700 0.425 390.2 446.9 56.6 144.4 69.500 0.300 307.3 405.4 98.1 46.3 22.300 0.250 366.0 391.1 25.1 21.2 10.200 0.212 361.4 362.8 1.4 19.8 9.500 0.180 354.5 364.0 9.4 10.4 5.000 0.150 349.6 351.4 1.8 8.6 4.100 0.125 349.0 350.5 1.5 7.1 3.400 0.106 355.5 357.4 1.9 5.2 2.500 0.090 338.9 341.2 2.3 2.9 1.300 0.075 297.1 297.8 0.6 2.3 1.100 0.063 351.3 352.1 0.8 1.5 0.007 Pan 360.9 362.4 1.5 0.0 0.000
Total mass retained on sieve = 207.8g
Table A5.4: Aggregate size distribution data for soil 1 (5.3% oil content).
141
Mass of soil used for sieve analysis = 214.2g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.00 498.5 513.7 15.2 196.9 92.800 0.425 390.2 465.2 75.0 121.9 57.500 0.300 307.3 386.2 78.8 43.1 20.300 0.250 366.0 388.1 21.9 21.2 10.000 0.212 361.4 363.8 2.4 18.8 8.900 0.180 354.6 365.4 10.8 8.0 3.800 0.150 349.6 351.6 2.0 6.0 2.800 0.125 349.0 350.5 1.5 4.5 2.100 0.106 355.5 356.7 1.2 3.3 1.600 0.090 338.9 341.0 2.1 1.2 0.006 0.075 297.1 297.5 0.3 0.9 0.004 0.063 351.4 351.7 0.3 0.6 0.003 Pan 360.9 361.5 0.6 0.0 0.000
Total mass retained on sieve = 212.1g
Table A5.5: Aggregate size distribution data for soil 1 (7.1% oil content).
A5.2 Soil 2
Mass of soil used for sieve analysis = 200.0g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.3 499.0 0.7 198.2 99.600 0.425 390.2 416.2 26.0 172.2 86.600 0.300 307.4 400.3 92.9 79.3 39.900 0.250 366.2 430.2 64 15.3 7.700 0.212 361.4 366.5 5.1 10.2 5.100 0.180 354.6 361.3 6.7 3.5 1.700 0.150 349.6 350.3 0.7 2.8 1.400 0.125 349.0 349.8 0.8 2 1.000 0.106 355.5 356.1 0.6 1.4 0.007 0.090 339.0 339.8 0.8 0.6 0.003 0.075 297.2 297.3 0.1 0.5 0.003 0.063 351.4 351.5 0.1 0.4 0.002 Pan 360.9 361.3 0.4 0.0 0.000
Total mass retained on sieve = 198.9g
Table A5.6: Aggregate size distribution data for soil 2 (0.0% oil content).
142
Mass of soil used for sieve analysis = 203.5g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.3 500.5 2.2 198.9 98.900 0.425 390.1 417.8 27.7 171.2 85.100 0.300 307.4 377.0 69.6 101.6 50.500 0.25 366.2 438.3 72.1 29.5 14.700
0.212 361.4 373.0 11.6 17.9 8.900 0.180 354.6 365.0 10.3 7.6 3.800 0.150 349.6 352.6 3.0 4.6 2.300 0.125 349.0 349.9 0.9 3.7 1.800 0.106 355.5 357.0 1.5 2.2 1.100 0.090 339.0 340.5 1.5 0.7 0.003 0.075 297.2 297.3 0.1 0.6 0.003 0.063 351.4 361.6 0.2 0.4 0.002 Pan 360.9 361.3 0.4 0.0 0.000
Total mass retained on sieve = 201.1g
Table A5.7: Aggregate size distribution data for soil 2 (1.8% oil content).
Mass of soil used for sieve analysis = 207.1g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.3 499.3 1.0 203.7 99.500 0.425 390.1 419.9 29.8 173.9 85.000 0.300 307.2 413.5 106.3 67.6 33.000 0.250 366.1 407.1 41.0 26.6 13.000 0.212 361.4 363.6 2.2 24.4 11.900 0.180 354.6 367.4 12.8 11.6 5.700 0.150 349.6 352.5 2.9 8.7 4.300 0.125 349.0 350.8 1.8 6.9 3.400 0.106 355.5 357.4 1.9 5.0 2.400 0.090 338.9 341.3 2.4 2.6 1.300 0.075 297.2 297.7 0.5 2.1 1.000 0.063 351.4 352.0 0.6 1.5 0.007 Pan 360.9 362.4 1.5 0.0 0.000
Total mass retained on sieve = 204.7g
Table A5.8: Aggregate size distribution data for soil 2 (3.5% oil content).
143
Mass of soil used for sieve analysis = 210.6g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.3 500.7 2.4 205.3 98.900 0.425 390.2 447.4 57.2 148.1 71.300 0.300 307.3 420.2 112.9 35.2 16.900 0.250 366.1 380.2 14.1 21.1 10.200 0.212 361.4 364.2 2.8 18.3 8.800 0.180 354.6 362.0 7.4 10.9 5.200 0.150 349.6 354.4 4.8 6.1 2.900 0.125 349.0 350.6 1.6 4.5 2.200 0.106 355.5 356.9 1.4 3.1 1.500 0.090 338.9 341.1 2.2 0.9 0.004 0.075 297.2 297.5 0.3 0.6 0.002 0.063 351.3 351.6 0.3 0.3 0.001 Pan 360.9 361.2 0.3 0.0 0.000
Total mass retained on sieve = 207.7g
Table A5.9: Aggregate size distribution data for soil 2 (5.3% oil content).
Mass of soil used for sieve analysis = 214.2g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 498.3 503.1 4.8 207.5 97.700 0.425 390.2 461.7 71.5 136.0 64.100 0.300 307.3 411.7 104.4 31.6 14.900 0.250 366.1 378.4 12.3 19.3 9.100 0.212 361.3 363.6 2.3 17.0 8.000 0.180 354.6 361.2 6.6 10.4 4.900 0.150 349.6 356.7 7.1 3.3 1.600 0.125 349.0 350.2 1.2 2.1 0.010 0.106 355.5 356.7 1.2 0.9 0.004 0.090 338.9 339.7 0.8 0.1 0.0005 0.075 297.1 297.2 0.1 0.0 0.000 0.063 351.3 351.3 0.0 0.0 0.000 Pan 360.9 360.9 0.0 0.0 0.000
Total mass retained on sieve = 212.3g
Table A5.10: Aggregate size distribution data for soil 2 (7.1% oil content).
144
A5.3 Soil 3
Mass of soil used for sieve analysis = 200.0g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on
sieve (g)
Cumulative passed (g)
Total percent passed
(%)
2.000 498.2 498.9 0.7 198.3 99.600 0.425 390.3 405.1 14.8 183.5 92.200 0.300 307.4 392.5 85.1 98.4 49.400 0.250 366.2 423.4 57.2 41.2 20.700 0.212 361.4 381.6 20.2 21.0 10.600 0.180 354.5 370.2 15.7 5.3 2.700 0.150 349.6 352.2 2.6 2.7 1.400 0.125 349.0 349.4 0.4 2.3 1.200 0.106 355.5 356.2 0.7 1.6 0.008 0.090 339.0 339.9 0.9 0.7 0.004 0.075 297.2 297.4 0.2 0.5 0.003 0.063 351.3 351.5 0.2 0.3 0.002 Pan 360.9 361.2 0.3 0.0 0.000
Total mass retained on sieve = 199.0g
Table A5.11: Aggregate size distribution data for soil 3 (0.0% oil content).
Mass of soil used for sieve analysis = 203.5g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 498.1 499.4 1.3 200.9 99.400 0.425 390.3 416.6 26.3 174.9 86.500 0.300 307.3 381.7 74.4 100.2 49.600 0.250 366.2 428.3 62.1 38.1 18.800 0.212 361.4 374.1 12.7 25.4 12.600 0.180 354.6 373.0 18.4 7.0 3.500 0.150 349.6 354.0 4.4 2.6 1.300 0.125 349.0 349.4 0.4 2.2 1.100 0.106 355.5 356.1 0.6 1.6 0.008 0.090 338.9 339.9 1.0 0.6 0.003 0.075 297.2 297.3 0.1 0.5 0.002 0.063 351.3 351.4 0.1 0.4 0.002 Pan 360.8 361.2 0.4 0.0 0.000
Total mass retained on sieve = 202.2g
Table A5.12: Aggregate size distribution data for soil 3 (1.8% oil content).
145
Mass of soil used for sieve analysis = 207.1g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.00 498.2 499.6 1.4 203.8 99.300 0.425 390.1 416.6 26.5 177.3 86.400 0.300 307.3 401.9 94.6 82.7 40.300 0.250 366.2 414.6 48.4 34.3 16.700 0.212 361.4 365.9 4.5 29.8 14.500 0.180 354.7 371.5 16.8 13 6.300 0.150 349.7 357.3 7.6 5.4 2.600 0.125 349.1 350.3 1.2 4.2 2.000 0.106 355.5 356.8 1.3 2.9 1.400 0.090 339.0 341.1 2.1 0.8 0.004 0.075 297.2 297.3 0.1 0.7 0.003 0.063 351.2 351.6 0.4 0.3 0.002 Pan 360.9 361.2 0.3 0.0 0.000
Total mass retained on sieve = 205.2g
Table A5.13: Aggregate size distribution data for soil 3 (3.5% oil content).
Mass of soil used for sieve analysis = 210.6g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 498.1 501.6 3.5 205.3 98.300 0.425 390.1 440.1 50.1 155.2 74.300 0.300 307.4 418.1 110.7 44.5 21.300 0.250 366.2 384.5 18.3 26.2 12.500 0.212 361.4 364.5 3.1 23.1 11.100 0.180 354.7 366.6 11.9 11.2 5.400 0.150 349.6 354.6 5.0 6.2 3.000 0.125 349.1 350.7 1.6 4.6 2.200 0.106 355.5 357.0 1.5 3.1 1.500 0.090 339.0 341.2 2.2 0.9 0.004 0.075 297.2 297.6 0.4 0.5 0.002 0.063 351.3 351.5 0.2 0.3 0.001 Pan 360.9 361.2 0.3 0.0 0.000
Total mass retained on sieve = 208.8g
Table A5.14: Aggregate size distribution data for soil 3 (5.3% oil content).
146
Mass of soil used for sieve analysis = 214.2g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 498.1 505.8 7.7 204.7 96.400 0.425 390.1 481.5 91.3 113.4 53.400 0.300 307.5 412.1 104.6 8.8 4.100 0.250 366.2 367.7 1.5 7.3 3.400 0.212 361.4 363.0 1.6 5.7 2.700 0.180 354.7 357.1 2.4 3.3 1.600 0.150 349.6 351.7 2.1 1.2 0.005 0.125 349.1 349.8 0.7 0.5 0.002 0.106 355.5 355.9 0.4 0.1 0.0005 0.090 339.0 339.1 0.1 0.0 0.000 0.075 297.2 297.2 0.0 0.0 0.000 0.063 351.3 351.3 0.0 0.0 0.000 Pan 360.9 360.9 0.0 0.0 0.000
Total mass retained on sieve = 212.4g
Table A5.15: Aggregate size distribution data for soil 3 (7.1% oil content).
A5.4 Soil 4
Mass of soil used for sieve analysis = 200.0g
Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.6 497.1 0.5 198.5 99.700 0.425 420.9 424.9 4.0 194.5 97.700 0.300 307.6 365.0 57.4 137.1 68.900 0.250 366.1 416.2 50.1 87.0 43.700 0.212 361.4 392.1 30.7 56.3 28.300 0.180 354.6 395.0 40.4 15.9 8.000 0.150 349.6 360.8 11.2 4.7 2.400 0.125 349.1 350.2 1.1 3.6 1.800 0.106 355.8 356.5 0.7 2.9 1.500 0.090 338.8 340.1 1.3 1.6 0.008 0.075 297.1 297.5 0.4 1.2 0.006 0.063 351.1 351.4 0.3 0.9 0.005 Pan 325.6 326.5 0.9 0.0 0.000
Total mass retained on sieve = 199.0g
Table A5.16: Aggregate size distribution data for soil 4 (0.0% oil content).
147
Mass of soil used for sieve analysis = 203.5g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and sand
(g)
Mass retained on
sieve (g)
Cumulative passed (g)
Total percent passed
(%)
2.000 496.6 497.5 0.9 199.8 99.600 0.425 420.9 430.2 9.3 190.5 94.900 0.300 307.5 387.1 79.6 110.9 55.300 0.250 365.9 426.2 60.3 50.6 25.200 0.212 361.4 371.6 10.2 40.4 20.100 0.180 354.5 372.2 17.7 22.7 11.300 0.150 349.6 358.2 8.6 14.1 7.000 0.125 349.0 350.1 1.1 13.0 6.500 0.106 355.5 357.5 2.0 11.0 5.500 0.090 338.8 342.5 3.7 7.3 3.600 0.075 297.1 298.0 0.9 6.4 3.200 0.063 351.1 352.4 1.3 5.1 2.500 Pan 325.6 330.7 5.1 0.0 0.000
Total mass retained on sieve = 200.7g
Table A5.17: Aggregate size distribution data for soil 4 (1.8% oil content).
Mass of soil used for sieve analysis = 207.1g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 496.9 498.9 2.0 202.6 99.000 0.425 420.7 440.4 19.7 182.9 89.400 0.300 307.2 376.7 69.5 113.4 55.400 0.250 366.0 425.2 59.2 54.2 20.600 0.212 361.1 373.2 12.1 42.1 10.400 0.180 354.5 375.3 20.8 21.3 6.400 0.150 349.5 357.7 8.2 13.1 5.600 0.125 348.7 350.4 1.7 11.4 3.900 0.106 355.6 359.1 3.5 7.9 5.500 0.090 338.8 342.6 3.8 4.1 2.000 0.075 297.1 297.6 0.5 3.6 1.700 0.063 350.9 352.0 1.1 2.5 1.200 Pan 325.5 328.0 2.5 0.0 0.000
Total mass retained on sieve = 204.6g
Table A5.18: Aggregate size distribution data for soil 4 (3.5% oil content).
148
Mass of soil used for sieve analysis = 210.6g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.9 498.6 1.7 205.2 99.20000 0.425 420.7 496.2 75.5 129.7 62.70000 0.300 307.1 404.0 96.9 32.8 15.90000 0.250 366.0 383.8 17.8 15.0 7.20000 0.212 361.3 365.5 4.2 10.8 5.20000 0.180 354.4 360.3 5.9 4.9 2.40000 0.150 349.5 352.1 2.6 2.3 1.10000 0.125 349.0 349.7 0.7 1.6 0.00800 0.106 355.5 356.2 0.7 0.9 0.00400 0.090 338.9 339.6 0.7 0.2 0.00097 0.075 297.1 297.2 0.1 0.1 0.00048 0.063 350.9 351.0 0.1 0.0 0.00000 Pan 325.5 325.5 0.0 0.0 0.00000
Total mass retained on sieve = 206.9g
Table A5.19: Aggregate size distribution data for soil 4 (5.3% oil content).
Mass of soil used for sieve analysis = 214.2g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.8 503.2 6.4 204.2 97.00000 0.425 420.6 556.3 135.7 68.5 32.50000 0.300 307.2 370.9 63.7 4.8 2.30000 0.250 366.0 368.4 2.4 2.4 1.10000 0.212 361.3 362.2 0.9 1.5 0.00700 0.180 354.5 355.4 0.9 0.6 0.00300 0.150 349.5 349.9 0.4 0.2 0.00095 0.125 349.0 349.2 0.2 0.0 0.00000 0.106 355.5 355.5 0.0 0.0 0.00000 0.090 338.9 338.9 0.0 0.0 0.00000 0.075 297.1 297.1 0.0 0.0 0.00000 0.063 350.9 350.9 0.0 0.0 0.00000 Pan 325.6 325.6 0.0 0.0 0.00000
Total mass retained on sieve = 210.6g
Table A5.20: Aggregate size distribution data for soil 4 (7.1% oil content).
149
A5.5 Soil 5
Mass of soil used for sieve analysis = 200.0g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.8 497.3 0.5 197.9 99.7 0.425 420.7 426.9 6.2 191.7 96.6 0.300 307.2 349.4 42.2 149.5 75.4 0.250 366.0 414.7 48.7 100.8 50.8 0.212 361.3 376.2 14.9 85.9 43.3 0.180 354.5 386.2 31.7 54.2 27.3 0.150 349.5 380.7 31.2 23.0 11.6 0.125 348.9 355.0 6.1 16.9 8.5 0.106 355.5 360.9 5.4 11.5 5.8 0.090 338.8 343.3 4.5 7.0 3.5 0.075 297.1 297.9 0.8 6.2 3.1 0.063 350.9 352.6 1.7 4.5 2.3 Pan 325.5 330.0 4.5 0.0 0.0
Total mass retained on sieve = 198.4g
Table A5.21: Aggregate size distribution data for soil 5 (0.0% oil content).
Mass of soil used for sieve analysis = 203.5g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.8 498.8 2.0 197.9 99.0 0.425 420.5 437.5 17.0 180.9 90.5 0.300 307.2 354.1 46.9 134.0 67.0 0.25 366.0 414.0 48.0 86.0 43.0
0.212 361.2 372.7 11.5 74.5 37.3 0.180 354.4 380.2 25.8 48.7 24.4 0.150 349.4 371.2 21.8 26.9 13.5 0.125 348.9 353.1 4.2 22.7 11.4 0.106 355.5 359.3 3.8 18.9 9.5 0.090 338.9 345.6 6.7 12.2 6.1 0.075 297.2 298.8 1.6 10.6 5.3 0.063 350.9 353.2 2.3 8.3 4.2 Pan 325.5 333.8 8.3 0.0 0.0
Total mass retained on sieve = 199.9g
Table A5.22: Aggregate size distribution data for soil 5 (1.8% oil content).
150
Mass of soil used for sieve analysis = 207.1g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.7 498.3 1.6 203.1 99.2 0.425 420.5 455.3 34.8 168.3 82.2 0.300 307.2 388.4 81.2 87.1 42.6 0.250 366.0 364.6 55.0 32.1 15.7 0.212 361.2 370.9 3.4 28.7 14.0 0.180 354.4 380.2 16.5 12.2 6.0 0.150 349.5 351.0 1.5 10.7 5.2 0.125 348.9 350.6 1.7 9.0 4.4 0.106 355.4 357.5 2.1 6.9 3.4 0.090 338.8 342.3 3.5 3.4 1.7 0.075 297.1 297.7 0.6 2.8 1.4 0.063 350.9 351.5 0.6 2.2 1.1 Pan 325.5 327.7 2.2 0.0 0.0
Total mass retained on sieve = 204.7g
Table A5.23: Aggregate size distribution data for soil 5 (3.5% oil content).
Mass of soil used for sieve analysis = 210.6g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g) Total percent passed
(%)
2.000 496.7 499.4 2.7 205.5 98.7000 0.425 420.6 500.4 79.8 125.7 60.4000 0.300 307.2 408.0 100.8 24.9 12.0000 0.250 365.8 379.9 14.1 10.8 5.2000 0.212 361.2 363.0 1.8 9.0 4.3000 0.180 354.5 358.8 4.3 4.7 2.3000 0.150 349.5 351.6 2.1 2.6 1.2000 0.125 348.8 350.0 1.2 1.4 0.0070 0.106 355.4 356.4 1.0 0.4 0.0020 0.090 338.8 339.1 0.3 0.1 0.0005 0.075 297.0 297.1 0.1 0.0 0.0000 0.063 350.9 350.9 0.0 0.0 0.0000 Pan 325.5 325.5 0.0 0.0 0.0000
Total mass retained on sieve = 208.2g
Table A5.24: Aggregate size distribution data for soil 5 (5.3% oil content).
151
Mass of soil used for sieve analysis = 214.2g Sieves (mm)
Mass of empty sieve
(g)
Mass of sieve and
sand (g)
Mass retained on sieve
(g)
Cumulative passed (g)
Total percent passed
(%)
2.000 496.6 512.0 15.4 196.4 92.7000 0.425 420.6 562.0 141.4 55.0 26.0000 0.300 307.3 358.8 51.5 3.5 1.7000 0.250 365.9 367.8 1.9 1.6 0.0080 0.212 361.1 362.5 1.4 0.2 0.0009 0.180 354.7 354.9 0.2 0.0 0.0000 0.150 349.5 349.5 0.0 0.0 0.0000 0.125 349.1 349.1 0.0 0.0 0.0000 0.106 355.3 355.3 0.0 0.0 0.0000 0.090 339.0 339.0 0.0 0.0 0.0000 0.075 297.1 297.1 0.0 0.0 0.0000 0.063 350.7 350.7 0.0 0.0 0.0000 Pan 325.5 325.5 0.0 0.0 0.0000
Total mass retained on sieve = 211.8g
Table A5.25: Aggregate size distribution data for soil 5 (7.1% oil content).
152
A6 Grading modulus
A6.1 Soil 1
Sieve Percentage retained
0.0% 1.8% 3.5% 5.3% 7.1% 2mm 0 3.74 3.82 3.27 7.1 0.425mm 4.5 12.26 22.06 27.24 35.36 0.075mm 0.2 0.2 0.1 0.3 0.001
Table A6.1: Percentage of mass of soil retained on sieves for soil 1.
A6.2 Soil 2
Sieve Percentage retained 0.0% 1.8% 3.5% 5.3% 7.1%
2mm 0.4 1.1 0.4 1.2 2.3 0.425mm 13.07 13.43 14.56 27.54 33.68 0.075mm 0.05 0.04 0.2 0.14 0.05
Table A6.2: Percentage of mass of soil retained on sieves for soil 2.
A6.3 Soil 3
Sieve Percentage retained 0.0% 1.8% 3.5% 5.3% 7.1%
2mm 0.4 0.6 0.7 1.7 3.63 0.425mm 7.44 13.01 12.91 23.99 42.98 0.075mm 0.1 0.05 0.05 0.2 0
Table A6.3: Percentage of mass of soil retained on sieves for soil 3.
A6.4 Soil 4
Sieve Percentage retained
0.0% 1.8% 3.5% 5.3% 7.1%
2mm 0.25 0.45 0.98 0.83 3.04
0.425mm 2.01 4.63 9.63 36.49 64.43
0.075mm 0.2 0.45 0.24 0.5 0
Table A6.4: Percentage of mass of soil retained on sieves for soil 4.
153
A6.5 Soil 5
Sieve Percentage retained
0.0% 1.8% 3.5% 5.3% 7.1% 2mm 0.25 1 0.78 1.29 7.27 0.425mm 3.13 8.5 17 38.32 66.76 0.075mm 0.4 0.8 0.29 0.05 0
Table A6.5: Percentage of mass of soil retained on sieves for soil 5.
Soils Grading modulus for oil contaminated soils
0.0% 1.8% 3.5% 5.3% 7.1% Soil 1 0.05 0.16 0.26 0.38 0.42 Soil 2 0.14 0.15 0.15 0.29 0.36 Soil 3 0.08 0.14 0.14 0.26 0.47 Soil 4 0.03 0.06 0.11 0.40 0.67 Soil 5 0.04 0.10 0.18 0.40 0.74
Table A6.6: Grading modulus of oil contaminated soils.
154
APPENDIX B
ATTERBERG LIMITS TESTS RESULTS B1 Atterberg limits data for soils
B1.1 Atterberg limits data for bentonite
Test number 1 2 3 4 Number of bumps 17 23 35 45 Mass of wet soil (g) 6.33 3.79 7.17 6.70
Mass of dry soil (g) 0.90 0.57 1.21 1.20 Water loss (g) 5.43 3.22 5.96 5.50 Water content (%) 603 565 493 458
Table B1.1: Liquid limit data for bentonite.
Liquid limit = 540%
Figure B1.1: Liquid limit of bentonite.
Test number 1 2 Mass of wet soil (g) 8.97 8.96 Mass of dry soil (g) 5.40 5.40 Water loss (g) 3.56 3.56 Water content (%) 65.93 65.93 Plastic limit (average) 65.93 Plastic limit 66
Table B1.2: Plastic limit data for bentonite.
155
B1.2 Atterberg limits data for kaolinite
Container number 1 2 3 4 Number of bumps 14 20 27 37 Mass of wet soil (g) 6.49 8.33 8.67 5.98
Mass of dry soil (g) 3.87 5.04 5.37 3.79 Water loss (g) 2.62 3.29 3.30 2.19
Water content (%) 67.70 65.27 61.45 57.78
Table B1.3: Liquid limit data for kaolinite.
Liquid limit = 61%
Figure B1.2: Liquid limit of kaolinite.
Test number 1 2 Mass of wet soil (g) 8.23 9.30 Mass of dry soil (g) 6.22 7.04
Water loss (g) 2.01 2.26 Water content (%) 32.31 32.10 Plastic limit (average) 32.21 Plastic limit 32
Table B1.4: Plastic limit data for kaolinite.
156
B1.3 Atterberg limits data for soil 1 (0.0% oil content)
Test number 1 2 3 4
Number of bumps 11 19 30 40 Mass of wet soil (g) 7.21 5.81 5.86 6.47
Mass of dry soil (g) 4.65 3.85 3.95 4.43
Water loss (g) 2.56 1.96 1.91 2.03 Water content (%) 55.05 50.91 48.35 45.82
Table B1.5: Liquid limit data for soil 1(0% oil content).
`
Liquid limit = 48%
Figure B1.3: Liquid limit of soil 1 (0.0% oil content).
Test number 1 2 Mass of wet soil (g) 7.90 14.38 Mass of dry soil (g) 7.00 12.74
Water loss (g) 0.90 1.64 Water content (%) 12.85 12.87 Plastic limit (average) 12.86 Plastic limit 13
Table B1.6: Plastic limit data for soil (0.0% oil content).
157
B1.4 Atterberg limits data for soil 1 (1.8% oil content)
Test number 1 2 3 4
Number of bumps 14 23 35 47
Mass of wet soil (g) 4.94 7.99 5.03 6.69 Mass of dry soil (g) 3.25 5.35 3.39 4.59
Water loss (g) 1.69 2.64 1.64 2.10
Water content (%) 52.00 49.34 48.38 45.75
Table B1.7: Liquid limit data for soil 1(1.8% oil content).
Liquid limit = 50%
Figure B1.4: Liquid limit of soil 1 (1.8% oil content).
Test number 1 2 Mass of wet soil (g) 7.58 11.72 Mass of dry soil (g) 6.61 10.22
Water loss (g) 0.97 1.50 Water content (%) 14.67 14.67 Plastic limit (average) 14.67 Plastic limit 15
Table B1.8: Plastic limit data for soil (1.8% oil content).
158
B1.5 Atterberg limits data for soil 1 (3.5% oil content)
Test number 1 2 3 4
Number of bumps 11 22 35 49 Mass of wet soil (g) 5.68 6.17 5.33 7.84 Mass of dry soil (g) 3.57 4.02 3.55 5.39 Water loss (g) 2.11 2.15 1.78 2.45 Water content (%) 59.10 53.48 50.14 45.45
Table B1.9: Liquid limit data for soil 1(3.5% oil content).
Liquid limit = 52%
Figure B1.5: Liquid limit of soil 1 (3.5% oil content).
Test number 1 2 Mass of wet soil (g) 11.73 11.73 Mass of dry soil (g) 10.16 10.16
Water loss (g) 1.57 1.57 Water content (%) 15.45 15.45 Plastic limit (average) 15.45 Plastic limit 15
Table B1.10: Plastic limit data for soil (3.5% oil content).
159
B1.6 Atterberg limits data for soil 1 (5.3% oil content)
Test number 1 2 3 4
Number of bumps 14 22 30 40 Mass of wet soil (g) 4.06 5.59 3.83 5.83 Mass of dry soil (g) 2.56 3.66 2.57 3.95 Water loss (g) 1.50 1.93 1.26 1.88 Water content (%) 58.59 52.73 49.02 47.59
Table B1.11: Liquid limit data for soil 1 (5.3% oil content).
Liquid limit = 54%
Figure B1.6: Liquid limit of soil 1 (5.3% oil content).
Test number 1 2 Mass of wet soil (g) 9.36 11.13 Mass of dry soil (g) 8.11 9.62
Water loss (g) 1.25 1.51 Water content (%) 15.41 15.69 Plastic limit (average) 15.55 Plastic limit 16
Table B1.12: Plastic limit data for soil (6% oil content).
160
B1.7 Atterberg limits data for soil 1 (7.1% oil content)
Test number 1 2 3 4 Number of bumps 12 20 30 42 Mass of wet soil (g) 4.45 5.85 4.91 3.86 Mass of dry soil (g) 2.78 3.69 3.12 2.51 Water loss (g) 1.67 2.16 1.79 1.35 Water content (%) 60.07 58.53 57.37 53.78
Table B1.13: Liquid limit data for soil 1 (7.1% oil content).
Liquid limit = 58%
Figure B1.7: Liquid limit of soil 1 (7.1% oil content).
Test number 1 2 Mass of wet soil (g) 9.32 11.98 Mass of dry soil (g) 8.03 10.35
Water loss (g) 1.29 1.63 Water content (%) 16.06 15.74 Plastic limit (average) 15.90 Plastic limit 16
Table B1.14: Plastic limit data for soil 1 (7.1% oil content).
161
B1.8 Atterberg limits data for soil 2 (0.0% oil content)
Test number 1 2 3 4 Number of bumps 11 23 30 40 Mass of wet soil (g) 4.43 4.17 5.20 7.14
Mass of dry soil (g) 2.44 2.35 3.09 4.28 Water loss (g) 1.99 1.82 2.11 2.86 Water content (%) 81.55 77.40 68.28 66.82
Table B1.15: Liquid limit data for soil 2 (0.0% oil content).
Liquid limit = 73%
Figure B1.8: Liquid limit of soil 2 (0.0% oil content).
Test number 1 2 Mass of wet soil (g) 11.09 11.09 Mass of dry soil (g) 9.46 9.46
Water loss (g) 1.63 1.63 Water content (%) 17.23 17.23 Plastic limit (average) 17.23 Plastic limit 17
Table B1.16: Plastic limit data for soil 2 (0.0% oil content).
162
B1.9 Atterberg limits data for soil 2 (1.8% oil content)
Test number 1 2 3 4
Number of bumps 12 20 32 44 Mass of wet soil (g) 4.61 3.65 5.34 5.05 Mass of dry soil (g) 2.60 2.13 3.15 3.01 Water loss (g) 2.01 1.52 2.19 2.04 Water content (%) 77.30 71.36 69.52 67.77
Table B1.17: Liquid limit data for soil 2 (1.8% oil content).
Liquid limit = 74%
Figure B1.9: Liquid limit of soil 2 (1.8% oil content).
Test number 1 2 Mass of wet soil (g) 8.15 8.93 Mass of dry soil (g) 6.95 7.61
Water loss (g) 1.20 1.32 Water content (%) 17.26 17.34 Plastic limit (average) 17.30 Plastic limit 17
Table B1.18: Plastic limit data for soil 2 (1.8% oil content).
163
B1.10 Atterberg limits data for soil 2 (3.5% oil content)
Test number 1 2 3 4
Number of bumps 12 20 32 42 Mass of wet soil (g) 6.20 4.47 4.66 4.43 Mass of dry soil (g) 3.48 2.53 2.77 2.64 Water loss (g) 2.72 1.94 1.89 1.79 Water content (%) 78.16 76.67 68.23 67.80
Table B1.19: Liquid limit data for soil 2 (3.5% oil content).
Liquid limit = 76%
Figure B1.10: Liquid limit of soil 2 (3.5% oil content).
Test number 1 2 Mass of wet soil (g) 9.14 8.24 Mass of dry soil (g) 7.77 7.01 Water loss (g) 1.37 1.23 Water content (%) 17.63 17.55 Plastic limit (average) 17.59 Plastic limit 18
Table B1.20: Plastic limit data for soil 2 (3.5% oil content).
164
B1.11 Atterberg limits data for soil 2 (5.3% oil content)
Test number 1 2 3 4
Number of bumps 11 21 31 48
Mass of wet soil (g) 4.07 5.14 3.09 5.94
Mass of dry soil (g) 2.26 2.86 1.74 3.51 Water loss (g) 1.81 2.28 1.35 2.43 Water content (%) 80.09 79.72 77.58 69.23
Table B1.21: Liquid limit data for soil 2 (5.3% oil content).
Liquid limit = 77%
Figure B1.11: Liquid limit of soil 2 (5.3% oil content).
Test number 1 2 Mass of wet soil (g) 9.18 9.05 Mass of dry soil (g) 7.80 7.70 Water loss (g) 1.38 1.35 Water content (%) 17.69 17.53 Plastic limit (average) 17.61 Plastic limit 18
Table B1.22: Plastic limit data for soil 2 (5.3% oil content).
165
B1.12 Atterberg limits data for soil 2 (7.1% oil content)
Test number 1 2 3 4
Number of bumps 13 23 32 43 Mass of wet soil (g) 5.87 5.23 3.66 6.23 Mass of dry soil (g) 3.28 2.99 2.11 3.65 Water loss (g) 2.59 2.24 1.55 2.58 Water content (%) 78.96 74.92 73.46 70.68
Table B1.23: Liquid limit data for soil 2 (7.1% oil content).
Liquid limit = 78%
Figure B1.12: Liquid limit of soil 2 (7.1% oil content).
Test number 1 2 Mass of wet soil (g) 9.38 10.96 Mass of dry soil (g) 7.96 9.30 Water loss (g) 1.42 1.66 Water content (%) 17.83 17.83 Plastic limit (average) 17.83 Plastic limit 18
Table B1.24: Plastic limit data for soil 2 (7.1% oil content).
166
B1.13 Atterberg limits data for soil 3 (0% oil content)
Test number 1 2 3 4 Number of bumps 12 23 39 49 Mass of wet soil (g) 6.94 5.05 4.77 4.75 Mass of dry soil (g) 3.67 2.71 2.60 2.59 Water loss (g) 3.27 2.34 2.17 2.16 Water content (%) 89.00 86.35 83.46 83.40
Table B1.25: Liquid limit data for soil 3 (0.0% oil content).
Liquid limit = 85%
Figure B1.13: Liquid limit of soil 3 (0.0% oil content).
Test number 1 2 Mass of wet soil (g) 9.66 9.92 Mass of dry soil (g) 8.16 8.38 Water loss (g) 1.50 1.54 Water content (%) 18.38 18.38 Plastic limit (average) 18.38 Plastic limit 18
Table B1.26: Plastic limit data for soil 3 (0.0% oil content).
167
B1.14 Atterberg limits data for soil 3 (1.8% oil content)
Test number 1 2 3 4 Number of bumps 11 20 37 47
Mass of wet soil (g) 5.42 4.76 4.59 4.89 Mass of dry soil (g) 2.82 2.53 2.47 2.65 Water loss (g) 2.60 2.23 2.12 2.24 Water content (%) 92.20 88.14 85.83 84.53
Table B1.27: Liquid limit data for soil 3 (1.8% oil content).
Liquid limit = 87%
Figure B1.14: Liquid limit of soil 3 (1.8% oil content).
Test number 1 2 Mass of wet soil (g) 14.86 6.99 Mass of dry soil (g) 12.49 5.85 Water loss (g) 2.37 1.14 Water content (%) 18.98 19.48 Plastic limit (average) 19.24 Plastic limit 19
Table B1.28: Plastic limit data for soil 3 (1.8% oil content).
168
B1.15 Atterberg limits data for soil 3 (3.5% oil content)
Test number 1 2 3 4 Number of bumps 12 23 35 45 Mass of wet soil (g) 7.37 4.61 6.62 6.01 Mass of dry soil (g) 3.62 2.43 3.50 3.24 Water loss (g) 3.75 2.18 3.12 2.77 Water content (%) 103.59 89.71 89.14 85.49
Table B1.29: Liquid limit data for soil 3 (3.5% oil content).
Liquid limit = 90%
Figure B1.15: Liquid limit of soil 3 (3.5% oil content).
Test number 1 2 Mass of wet soil (g) 9.21 10.49 Mass of dry soil (g) 7.64 8.70 Water loss (g) 1.57 1.79 Water content (%) 20.55 20.57 Plastic limit (average) 20.56 Plastic limit 21
Table B1.30: Plastic limit data for soil 3 (3.5% oil content).
169
B1.16 Atterberg limits data for soil 3 (5.3% oil content)
Test number 1 2 3 4 Number of bumps 13 24 35 49
Mass of wet soil (g) 6.26 4.51 5.50 4.99 Mass of dry soil (g) 3.13 2.34 3.02 2.76 Water loss (g) 3.13 2.17 2.48 2.23 Water content (%) 100 92.73 82.11 80.80
Table B1.31: Liquid limit data for soil 3 (5.3% oil content).
Liquid limit = 92%
Figure B1.16: Liquid limit of soil 3 (5.3% oil content).
Test number 1 2 Mass of wet soil (g) 9.14 9.48 Mass of dry soil (g) 7.50 7.80 Water loss (g) 1.64 1.68 Water content (%) 21.86 21.53 Plastic limit (average) 21.70 Plastic limit 22
Table B1.32: Plastic limit data for soil 3 (5.3% oil content).
170
B1.17 Atterberg limits data for soil 3 (7.1% oil content)
Test number 1 2 3 4
Number of bumps 14 24 37 47 Mass of wet soil (g) 4.20 3.88 5.59 3.25 Mass of dry soil (g) 2.09 1.98 2.92 1.71 Water loss (g) 2.11 1.90 2.67 1.54 Water content (%) 100.90 95.96 91.43 90.05
Table B1.33: Liquid limit data for soil 3 (7.1% oil content).
Liquid limit = 94%
Figure B1.17: Liquid limit of soil 3 (7.1% oil content).
Test number 1 2 Mass of wet soil (g) 8.60 10.06 Mass of dry soil (g) 7.00 8.20 Water loss (g) 1.60 1.86 Water content (%) 22.85 22.68 Plastic limit (average) 22.78 Plastic limit 23
Table B1.34: Plastic limit data for soil 3 (7.1% oil content).
171
B1.18 Atterberg limits data for soil 4 (0.0% oil content)
Test number 1 2 3 4
Number of bumps 12 17 38 47 Mass of wet soil (g) 7.13 4.73 7.28 6.44 Mass of dry soil (g) 3.56 2.38 3.71 3.30 Water loss (g) 3.57 2.35 3.57 3.14 Water content (%) 100.28 98.74 96.22 95.15
Table B1.35: Liquid limit data for soil 4 (0.0% oil content).
Liquid limit = 98%
Figure B1.18: Liquid limit of soil 4 (0.0% oil content).
Test number 1 2 Mass of wet soil (g) 11.46 9.82 Mass of dry soil (g) 9.57 8.20 Water loss (g) 1.89 1.62 Water content (%) 19.74 19.76 Plastic limit (average) 19.75 Plastic limit 20
Table B1.36: Plastic limit data for soil 4 (0.0% oil content).
172
B1.19 Atterberg limits data for soil 4 (1.8% oil content)
Test number 1 2 3 4
Number of bumps 13 21 35 45 Mass of wet soil (g) 8.07 5.53 7.34 5.50 Mass of dry soil (g) 3.82 2.74 3.87 2.91 Water loss (g) 4.25 2.79 3.47 2.59 Water content (%) 111.23 101.82 89.66 89.00
Table B1.37: Liquid limit data for soil 4 (1.8% oil content).
Liquid limit = 98%
Figure B1.19: Liquid limit of soil 4 (1.8% oil content).
Test number 1 2 Mass of wet soil (g) 10.68 10.68 Mass of dry soil (g) 8.89 8.89 Water loss (g) 1.79 1.79 Water content (%) 20.13 20.13 Plastic limit (average) 20.13 Plastic limit 20
Table B1.38: Plastic limit data for soil 4 (1.8% oil content).
173
B1.20 Atterberg limits data for soil 4 (3.5% oil content)
Container number 1 2 3 4
Number of bumps 13 22 32 46
Mass of wet soil (g) 5.75 7.99 6.81 5.81 Mass of dry soil (g) 2.72 3.89 3.42 3.04 Water loss (g) 3.03 4.10 3.39 2.77 Water content (%) 111.39 105.40 99.12 91.12
Table B1.39: Liquid limit data for soil 4 (3.5% oil content).
Liquid limit = 100%
Figure B1.20: Liquid limit of soil 4 (3.5% oil content).
Test number 1 2 Mass of wet soil (g) 11.08 10.14 Mass of dry soil (g) 9.08 8.31 Water loss (g) 2.00 1.83 Water content (%) 22.02 22.02 Plastic limit (average) 22.02 Plastic limit 22
Table B1.40: Plastic limit data for soil 4 (3.5% oil content).
174
B1.21 Atterberg limits data for soil 4 (5.3% oil content)
Test number 1 2 3 4 Number of bumps 12 20 37 45 Mass of wet soil (g) 5.40 8.22 7.06 6.16 Mass of dry soil (g) 2.53 3.94 3.39 2.96 Water loss (g) 2.87 4.28 3.67 3.20 Water content (%) 113.44 108.63 108.26 108.12
Table B1.41: Liquid limit data for soil 4 (5.3% oil content).
Liquid limit = 110%
Figure B1.21: Liquid limit of soil 4 (5.3% oil content).
Test number 1 2 Mass of wet soil (g) 10.31 12.07 Mass of dry soil (g) 8.44 9.88 Water loss (g) 1.87 2.19 Water content (%) 22.16 22.17 Plastic limit (average) 22.17 Plastic limit 22
Table B1.42: Plastic limit data for soil 4 (5.3% oil content).
175
B1.22 Atterberg limits data for soil 4 (7.1% oil content)
Test number 1 2 3 4
Number of bumps 13 22 35 45 Mass of wet soil (g) 7.03 5.15 5.27 5.03 Mass of dry soil (g) 3.05 2.28 2.37 2.28 Water loss (g) 3.98 2.87 2.90 2.75 Water content (%) 130.49 125.87 122.36 120.61
Table B1.43: Liquid limit data for soil 4 (7.1% oil content).
Liquid limit = 125%
Figure B1.22: Liquid limit of soil 4 (7.1% oil content).
Test number 1 2 Mass of wet soil (g) 10.04 12.70 Mass of dry soil (g) 8.14 10.46 Water loss (g) 1.90 2.44 Water content (%) 23.34 23.33 Plastic limit (average) 23.34 Plastic limit 23
Table B1.44: Plastic limit data for soil 4 (7.1% oil content).
176
B1.23 Atterberg limits data for soil 5 (0.0% oil content)
Test number 1 2 3 4
Number of bumps 14 22 35 45 Mass of wet soil (g) 8.19 8.06 7.40 5.87 Mass of dry soil (g) 3.58 3.58 3.36 2.72 Water loss (g) 4.61 4.48 4.04 3.15 Water content (%) 128.77 125.14 120.24 115.81
Table B1.45: Liquid limit data for soil 5 (0.0% oil content).
Liquid limit = 123%
Figure B1.23: Liquid limit of soil 5 (0.0% oil content).
Test number 1 2 Mass of wet soil (g) 10.80 11.18 Mass of dry soil (g) 8.83 9.14 Water loss (g) 1.97 2.04 Water content (%) 22.31 22.32 Plastic limit (average) 22.32 Plastic limit 22
Table B1.46: Plastic limit data for soil 5 (0.0% oil content).
177
B1.24 Atterberg limits data for soil 5 (1.8% oil content)
Test number 1 2 3 4
Number of bumps 14 22 36 42 Mass of wet soil (g) 7.24 6.09 5.94 5.45 Mass of dry soil (g) 3.12 2.65 2.67 2.51 Water loss (g) 4.12 3.44 3.27 2.94 Water content (%) 132.05 129.81 122.47 117.13
Table B1.47: Liquid limit data for soil 5 (1.8% oil content).
Liquid limit = 128%
Figure B1.24: Liquid limit of soil 5 (1.8% oil content).
Test number 1 2 Mass of wet soil (g) 12.29 10.10 Mass of dry soil (g) 2.30 8.21 Water loss (g) 9.99 1.89 Water content (%) 23.02 23.02 Plastic limit (average) 23.02 Plastic limit 23
Table B1.48: Plastic limit data for soil 5 (1.8% oil content).
178
B1.25 Atterberg limits data for soil 5 (3.5% oil content)
Test number 1 2 3 4
Number of bumps 12 20 38 47 Mass of wet soil (g) 6.52 5.93 5.82 7.63 Mass of dry soil (g) 2.83 2.58 2.55 3.35 Water loss (g) 3.69 3.35 3.27 4.28 Water content (%) 130.38 129.84 128.23 127.76
Table B1.49: Liquid limit data for soil 5 (3.5% oil content).
Liquid limit = 130%
Figure B1.25: Liquid limit of soil 5 (3.5% oil content).
Test number 1 2 Mass of wet soil (g) 12.25 9.32 Mass of dry soil (g) 9.91 7.54 Water loss (g) 2.34 1.78 Water content (%) 23.61 23.60 Plastic limit (average) 23.61 Plastic limit 24
Table B1.50: Plastic limit data for soil 5 (3.5% oil content).
179
B1.26 Atterberg limits data for soil 5 (5.3% oil content)
Test number 1 2 3 4
Number of bumps 13 22 35 44 Mass of wet soil (g) 7.33 5.56 6.47 5.60 Mass of dry soil (g) 3.12 2.37 2.76 2.39 Water loss (g) 4.21 3.19 3.71 3.21 Water content (%) 134.94 134.60 134.42 134.31
Table B1.51: Liquid limit data for soil 5 (5.3% oil content).
Liquid limit = 134%
Figure B1.26: Liquid limit of soil 5 (5.3% oil content).
Test number 1 2 Mass of wet soil (g) 10.76 10.97 Mass of dry soil (g) 8.70 8.87 Water loss (g) 2.06 2.10 Water content (%) 23.67 23.68 Plastic limit (average) 23.68 Plastic limit 24
Table B1.52: Plastic limit data for soil 5 (5.3% oil content).
180
B1.27 Atterberg limits data for soil 5 (7.1% oil content)
Test number 1 2 3 4
Number of bumps 12 22 35 47 Mass of wet soil (g) 8.95 6.45 5.75 5.80 Mass of dry soil (g) 3.78 2.74 2.45 2.48 Water loss (g) 5.17 3.71 3.30 3.32 Water content (%) 136.77 135.40 134.69 133.87
Table B1.53: Liquid limit data for soil 5 (7.1% oil content).
Liquid limit = 135%
Figure B1.27: Liquid limit of soil 5 (7.1% oil content).
Test number 1 2 Mass of wet soil (g) 8.98 12.72 Mass of dry soil (g) 7.25 10.27 Water loss (g) 1.73 2.45 Water content (%) 23.86 23.86 Plastic limit (average) 23.86 Plastic limit 24
Table B1.54: Plastic limit data for soil 5 (7.1% oil content).
181
B2 Oil loss test
Oil mixed into 250g of soil, some amount of the contaminated soil was put into a container and oven dried at 105 degree celsius for 24 hours
Oil loss test Oil content (%) 1.8% 3.5% 5.3% 7.1%
Mass of wet soil (g) 12.67 16.35 22.60 19.07 Mass of oil (g) 0.23 0.57 1.20 1.35 Mass of dry soil (g)
12.66 16.34 22.58 19.05
Oil loss (g) 0.01 0.01 0.02 0.02 Oil loss (%) of soil 0.08 0.06 0.09 0.10
Table B2.1: Oil loss test for soil 1
Oil loss test Oil content (%) 1.8% 3.5% 5.3% 7.1%
Mass of wet soil (g) 20.85 18.42 20.04 24.69 Mass of oil (g) 0.38 0.64 1.06 1.75 Mass of dry soil (g) 20.83 18.40 20.01 24.66
Oil loss (g) 0.02 0.02 0.03 0.03 Oil loss (%) of soil 0.10 0.11 0.15 0.12
Table B2.2: Oil loss test for soil 2
Oil loss test Oil content (%) 1.8% 3.5% 5.3% 7.1%
Mass of wet soil (g) 27.38 25.86 21.70 26.16 Mass of oil (g) 0.49 0.91 1.15 1.86 Mass of dry soil (g) 27.35 25.83 21.67 26.12
Oil loss (g) 0.03 0.03 0.03 0.04 Oil loss (%) of soil 0.11 0.12 0.14 0.15
Table B2.3: Oil loss test for soil 3
182
Oil loss test Oil content (%) 1.8% 3.5% 5.3% 7.1%
Mass of wet soil (g) 23.59 25.17 25.03 21.94
Mass of oil (g) 0.43 0.88 1.33 1.56 Mass of dry soil (g) 23.55 25.13 24.99 21.90
Oil loss (g) 0.04 0.04 0.04 0.04 Oil loss (%) of soil 0.17 0.16 0.16 0.23
Table B2.4: Oil loss test for soil 4
Oil loss test Oil content (%) 1.8% 3.5% 5.3% 7.1%
Mass of wet soil (g) 23.26 23.56 23.25 20.38 Mass of oil (g) 0.42 0.83 1.25 1.45 Mass of dry soil (g) 23.21 23.51 23.19 20.32
Oil loss (g) 0.05 0.05 0.06 0.06 Oil loss (%) of soil 0.22 0.21 0.26 0.30
Table B2.5: Oil loss test for soil 5
Soil Oil content (%) 1.8% 3.5% 5.3% 7.1%
Soil 1 4.3 1.8 1.7 1.5 Soil 2 5.3 3.1 2.8 1.7 Soil 3 6.1 3.3 2.6 2.2
Soil 4 9.3 4.5 3.0 2.6 Soil 5 11.9 6.0 4.8 4.1
Table B2.6: Oil loss (g) per mass of oil (g) in soil, in percentage
183
Soil Oil content
(%) Liquid
Limit (%) Plastic
Limit (%) Plasticity Index
(%)
Soil 1
0.0 48 13 35 1.8 50 15 35 3.5 52 15 37 5.3 54 16 38 7.1 58 16 42
Soil 2
0.0 73 17 56 1.8 74 17 57 3.5 76 18 58 5.3 77 18 59 7.1 78 18 60
Soil 3
0.0 85 18 67 1.8 87 19 68 3.5 90 21 69 5.3 92 22 70 7.1 94 23 71
Soil 4
0.0 98 20 78 1.8 98 20 78 3.5 100 22 78 5.3 110 22 88 7.1 125 23 102
Soil 5
0.0 123 22 101 1.8 128 23 105 3.5 130 24 106 5.3 135 24 111 7.1 135 24 111
Table B3: Atterberg limits and plasticity index of soils
184
Table B4: Total fluid content at Atterberg limits and plasticity index of soils
Soil Oil content(%)
Total fluid content at
Liquid Limit (%)
Total fluid content at
Plastic Limit (%)
Plasticity Index
(%)
Soil 1
0.0 48 13 35 1.8 52 17 37 3.5 56 19 41 5.3 59 21 43 7.1 65 23 49
Soil 2
0.0 73 17 56 1.8 76 19 59 3.5 80 22 62 5.3 82 23 64 7.1 85 25 67
Soil 3
0.0 85 18 67 1.8 89 21 70 3.5 94 25 73 5.3 97 27 75 7.1 101 30 78
Soil 4
0.0 98 20 78 1.8 100 22 80 3.5 104 26 82 5.3 115 27 93 7.1 132 30 109
Soil 5
0.0 123 22 101 1.8 130 25 107 3.5 134 28 110 5.3 140 29 116 7.1 142 31 118
185
APPENDIX C
COMPACTION TEST RESULTS
Data 1 2 3 4 5 Soil + mould + base plate (g) 6345 6397 6472 6489 6460
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1955 2007 2082 2099 2070 Bulk density (g/cm3) 1.955 2.007 2.082 2.099 2.070 Water content (%) 9 10 11 12 13 Total fluid content (%) 9 10 11 12 13
Table C1.1: Compaction data for soil 1 (0.0% oil content).
Data 1 2 3 4 5
Soil + mould + base plate (g) 6231 6298 6443 6459 6441 Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1841 1908 2053 2069 2051 Bulk density (g/cm3) 1.841 1.908 2.053 2.069 2.051 Water content (%) 5 7 10 11 12 Total fluid content (%) 6.8 8.8 11.8 12.8 13.8
Table C1.2: Compaction data for soil 1 (1.8% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6283 6329 6427 6462 6434 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1894 1939 2037 2072 2044 Bulk density (g/cm3) 1.894 1.939 2.037 2.072 2.044 Water content (%) 5 7 8 10 11 Total fluid content (%) 8.5 10.5 11.5 13.5 14.5
Table C1.3: Compaction data for soil 1 (3.5% oil content).
186
Data 1 2 3 4 5 Soil + mould + base plate (g) 6344 6419 6442 6452 6419 Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1954 2029 2052 2062 2029 Bulk density (g/cm3) 1.954 2.029 2.052 2.062 2.029 Water content (%) 6 8 9 10 11 Total fluid content (%) 11.3 13.3 14.3 15.3 16.3
Table C1.4: Compaction data for soil 1 (5.3% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6299 6321 6360 6388 6391
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1909 1931 1970 1998 2001 Bulk density (g/cm3) 1.909 1.931 1.970 1.998 2.001 Water content (%) 2 3 4 6 7 Total fluid content (%) 9.1 10.1 11.1 13.1 14.1
Table C1.5: Compaction data for soil 1 (7.1% oil content).
187
Data 1 2 3 4 5 Soil + mould + base plate (g) 6255 6374 6491 6508 6420
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1865 1984 2101 2118 2030
Bulk density (g/cm3) 1.865 1.984 2.101 2.118 2.03 Water content (%) 7 8 11 12 13 Total fluid content (%) 7 8 11 12 13
Table C1.6: Compaction data for soil 2 (0.0% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6374 6409 6464 6455 6450 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1984 2019 2074 2065 2060 Bulk density (g/cm3) 1.984 2.019 2.074 2.065 2.060 Water content (%) 9 10 11 12 13 Total fluid content (%) 10.8 11.8 12.8 13.8 14.8
Table C1.7: Compaction data for soil 2 (1.8% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6291 6377 6415 6464 6434
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1901 1987 2025 2074 2044 Bulk density (g/cm3) 1.901 1.987 2.025 2.074 2.044 Water content (%) 6 7 8 10 11 Total fluid content (%) 9.5 10.5 11.5 13.5 14.5
Table C1.8: Compaction data for soil 2 (3.5% oil content).
188
Data 1 2 3 4 5
Soil + mould + base plate (g) 6366 6387 6436 6438 6392 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1976 1997 2046 2048 2002 Bulk density (g/cm3) 1.976 1.997 2.046 2.048 2.002 Water content (%) 7 8 10 11 12 Total fluid content (%) 12.3 13.3 15.3 16.3 17.3
Table C1.9: Compaction data for soil 2 (5.3% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6285 6343 6385 6400 6417 Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1895 1953 1995 2010 2027 Bulk density (g/cm3) 1.895 1.953 1.995 2.01 2.027 Water content (%) 4 5 7 8 10 Total fluid content (%) 11.1 12.1 14.1 15.1 17.1
Table C1.10: Compaction data for soil 2 (7.1% oil content).
189
Data 1 2 3 4 5 Soil + mould + base plate (g) 6262 6315 6385 6417 6395 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1872 1925 1995 2027 2005
Bulk density (g/cm3) 1.872 1.925 1.995 2.027 2.005 Water content (%) 8 9 10 11 12 Total fluid content (%) 8 9 10 11 12
Table C1.11: Compaction data for soil 3 (0.0% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6306 6369 6406 6404 6401
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1916 1979 2016 2014 2011
Bulk density (g/cm3) 1.916 1.979 2.016 2.014 2.011 Water content (%) 8 9 10 11 12
Total fluid content (%) 9.8 10.8 11.8 12.8 13.8
Table C1.12: Compaction data for soil 3 (1.8% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6238 6283 6395 6414 6400 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1848 1893 2005 2024 2010
Bulk density (g/cm3) 1.848 1.893 2.005 2.024 2.010 Water content (%) 6 7 9 10 12 Total fluid content (%) 9.5 10.5 12.5 13.5 15.5
Table C1.13: Compaction data for soil 3 (3.5% oil content).
190
Data 1 2 3 4 5 Soil + mould + base plate (g) 6241 6319 6368 6411 6375 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1851 1929 1978 2021 1985 Bulk density (g/cm3) 1.851 1.929 1.978 2.021 1.985 Water content (%) 5 7 8 10 12 Total fluid content (%) 10.3 12.3 13.3 15.3 17.3
Table C1.14: Compaction data for soil 3 (5.3% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6297 6352 6375 6386 6373 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1907 1962 1985 1996 1983 Bulk density (g/cm3) 1.907 1.962 1.985 1.996 1.983 Water content (%) 4 6 7 8 9 Total fluid content (%) 11.1 13.1 14.1 15.1 16.1
Table C1.15: Compaction data for soil 3 (7.1% oil content).
191
Data 1 2 3 4 5 Soil + mould + base plate (g) 6197 6245 6358 6320 6300
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1807 1855 1968 1930 1910
Bulk density (g/cm3) 1.807 1.855 1.968 1.930 1.910 Water content (%) 6 8 12 13 14 Total fluid content (%) 6 8 12 13 14
Table C1.16: Compaction data for soil 4 (0.0% oil content).
Data 1 2 3 4 5
Soil + mould + base plate (g) 6236 628 6340 6334 6308
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1846 1897 1950 1944 1918
Bulk density (g/cm3) 1.846 1.897 1.950 1.944 1.918 Water content (%) 8 9 11 12 13 Total fluid content (%) 9.8 10.8 12.8 13.8 14.8
Table C1.17: Compaction data for soil 4 (1.8% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6237 6271 6298 6360 6325
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1847 1881 1908 1970 1935 Bulk density (g/cm3) 1.847 1.881 1.908 1.970 1.935 Water content (%) 7 8 9 11 12 Total fluid content (%) 10.5 11.5 12.5 14.5 15.5
Table C1.18: Compaction data for soil 4 (3.5% oil content).
192
Data 1 2 3 4 5
Soil + mould + base plate (g) 6205 6270 6329 6364 6366
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1815 1880 1939 1974 1976 Bulk density (g/cm3) 1.815 1.880 1.939 1.974 1.976 Water content (%) 4 6 8 10 12 Total fluid content (%) 9.3 11.3 13.3 15.3 17.3
Table C1.19: Compaction data for soil 4 (5.3% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6255 6282 6306 6339 6369
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil ( g ) 1815 1880 1939 1974 1976
Bulk density (g/cm3) 1.865 1.892 1.916 1.949 1.979 Water content (%) 3 4 5 7 9 Total fluid content (%) 10.1 11.1 12.1 14.1 16.1
Table C1.20: Compaction data for soil 4 (7.1% oil content).
193
Data 1 2 3 4 5
Soil + mould + base plate (g) 6204 6282 6349 6372 6361
Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1814 1892 1959 1982 1971
Bulk density (g/cm3) 1.814 1.892 1.959 1.982 1.971 Water content (%) 9 10 13 15 16 Total fluid content (%) 9 10 13 15 16
Table C1.21: Compaction data for soil 5 (0.0% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6260 6294 6321 6327 6340 Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1870 1904 1931 1937 1950 Bulk density (g/cm3) 1.870 1.904 1.931 1.937 1.95 Water content (%) 9 10 11 12 13 Total fluid content (%) 10.8 11.8 12.8 13.8 14.8
Table C1.22: Compaction data for soil 5 (1.8% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6253 6281 6337 6318 6300
Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1863 1891 1947 1928 1910 Bulk density (g/cm3) 1.863 1.891 1.947 1.928 1.910 Water content (%) 9 10 12 13 14 Total fluid content (%) 12.5 13.5 15.5 16.5 17.5
Table C1.23: Compaction data for soil 5 (3.5% oil content).
194
Data 1 2 3 4 5
Soil + mould + base plate (g) 6290 6317 6345 6339 6322 Mould + base plate (g) 4390 4390 4390 4390 4390
Mass of soil (g) 1990 1927 1955 1949 1932
Bulk density (g/cm3) 1.900 1.927 1.955 1.949 1.932 Water content (%) 9 10 11 13 14 Total fluid content (%) 14.3 15.3 16.3 18.3 19.3
Table C1.24: Compaction data for soil 5 (5.3% oil content).
Data 1 2 3 4 5 Soil + mould + base plate (g) 6290 6314 6334 6345 6352 Mould + base plate (g) 4390 4390 4390 4390 4390 Mass of soil (g) 1900 1924 1944 1955 1962
Bulk density (g/cm3) 1.900 1.924 1.944 1.955 1.962 Water content (%) 8 9 10 11 12 Total fluid content (%) 15.1 16.1 17.1 18.1 19.1
Table C1.25: Compaction data for soil 5 (7.1% oil content).
195
Oil
cont
ent (
%)
Soil 1 Soil 2 Soil 3 Soil 4 Soil 5
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
wat
er
cont
ent (
%)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
wat
er
cont
ent (
%)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
wat
er
cont
ent (
%)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
wat
er
cont
ent (
%)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
wat
er
cont
ent (
%)
0.0 1.880 11.4 1.896 11.7 1.828 11.0 1.757 12.0 1.734 13.0
1.8 1.840 10.1 1.839 11.0 1.804 10.4 1.729 11.0 1.712 11.4
3.5 1.838 9.1 1.830 9.8 1.786 9.6 1.722 10.9 1.688 11.8
5.3 1.798 8.9 1.775 10.0 1.756 9.0 1.714 9.2 1.680 11.4
7.1 1.774 4.4 1.748 7.0 1.740 7.0 1.712 6.4 1.660 10.0
Table C2: Variation of maximum dry density with optimum water content of soils.
Oil
cont
ent (
%)
Soil 1 Soil 2 Soil 3 Soil 4 Soil 5
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
tota
l flu
id c
onte
nt (%
)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
tota
l flu
id c
onte
nt (%
)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
tot
al
fluid
con
tent
(%)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
tota
l flu
id c
onte
nt (%
)
Max
imum
dry
de
nsity
(g/c
m3 )
Opt
imum
tota
l flu
id c
onte
nt (%
)
0.0 1.880 11.4 1.896 11.7 1.828 11.0 1.757 12.0 1.734 13.0
1.8 1.840 11.9 1.839 12.8 1.804 12.2 1.729 12.8 1.712 13.2
3.5 1.838 12.6 1.830 13.3 1.786 13.1 1.722 14.4 1.688 15.3
5.3 1.798 14.2 1.775 15.3 1.756 14.3 1.714 14.5 1.680 16.7
7.1 1.774 11.5 1.748 14.1 1.740 14.1 1.712 13.5 1.660 17.1
Table C3: Variation of maximum dry density with optimum total fluid content of soils.
196
Table C4: Variation of maximum dry density with optimum water content of soils used
by some previous researchers.
Reference Soils Oil
content (%)
Maximum dry density
(g/cm3)
Optimum water content
(%)
Rahman et al (2011) Metasedimentary
0 1.56 22.0 4 1.70 22.0 8 1.68 21.0 12 1.90 16.0 16 1.78 8.0
Al-Sanad et al (1995) Poorly graded sand
0 1.89 13.0 2 1.95 8.0 4 1.93 7.0 6 1.83 2.0
Khamehchiyan et al (2007)
Poorly graded sand
0 1.83 14.0 4 1.83 11.0 8 1.82 8.0 12 1.82 5.0 16 1.81 3.0
Sand with 5 to 15% silt
0 1.91 13.0 4 1.87 9.0 8 1.84 9.0 12 1.85 4.5 16 1.82 2.0
Low plasticity clay
0 1.86 16.0 4 1.84 14.0 8 1.83 9.0 12 1.80 7.0 16 1.81 3.0
Rahman et al (2010)
Grade V (basaltic)
0 1.67 24.0 4 1.57 22.0 8 1.55 20.0 12 1.53 18.0 16 1.50 18.0
Grade VI (basaltic)
0 1.60 23.0 4 1.57 23.0 8 1.56 22.0 12 1.55 20.0 16 1.55 17.0
Rahman et al (2011) Granitic Sandy loam
0 1.50 18.0 4 1.46 19.0 8 1.50 23.0 12 1.37 17.0 16 1.40 18.0
197
Table C5: Variation of maximum dry density with optimum total fluid content of soils
used by some previous researchers.
Reference Soils Oil
content (%)
Maximum dry density
(g/cm3)
Optimum total fluid content
(%)
Rahman et al (2011) Metasedimentary
0 1.56 22.0 4 1.70 26.0 8 1.68 29.0
12 1.90 28.0 16 1.78 24.0
Al-Sanad et al (1995) Poorly graded sand
0 1.89 13.0 2 1.95 10.0 4 1.93 11.0 6 1.83 8.0
Khamehchiyan et al (2007)
Poorly graded sand
0 1.83 14.0 4 1.83 15.0 8 1.82 16.0
12 1.82 17.0 16 1.81 19.0
Sand with 5 to 15% silt
0 1.91 13.0 4 1.87 13.0 8 1.84 17.0
12 1.85 16.5 16 1.82 18.0
Low plasticity clay
0 1.86 16.0 4 1.84 18.0 8 1.83 17.0
12 1.80 19.0 16 1.81 19.0
Rahman et al (2010)
Grade V (basaltic)
0 1.67 24.0 4 1.57 26.0 8 1.55 28.0
12 1.53 30.0 16 1.50 34.0
Grade VI (basaltic)
0 1.60 23.0 4 1.57 27.0 8 1.56 30.0
12 1.55 32.0 16 1.55 33.0
Rahman et al (2011) Granitic sandy loam
0 1.50 18.0 4 1.46 23.0 8 1.50 31.0
12 1.37 29.0 16 1.40 34.0
198
APPENDIX D
PLASTICITY CHARACTERISTICS AND COMPACTION OF CONTAMINATED SOIL
Oil content
(%)
Maximum dry density
(%)
Optimum water
content (%)
Optimum fluid
Content (%)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 1.880 11.4 11.4 48 13 35
1.8 1.840 10.1 11.9 50 15 35
3.5 1.838 9.1 12.6 52 15 37 5.3 1.798 8.9 14.2 54 16 38 7.1 1.774 4.4 11.5 58 16 42
Table D1.1: Plasticity and compaction characteristics of soil 1.
Oil content
(%)
Maximum dry density
(g/cm3)
Optimum water
content (%)
Optimum fluid
content (%)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 1.896 11.7 11.7 73 17 56 1.8 1.839 11.0 12.8 74 17 57 3.5 1.830 9.8 13.3 76 18 58
5.3 1.775 10.0 15.3 77 18 59 7.1 1.748 7.0 14.1 78 18 60
Table D1.2: Plasticity and compaction characteristics of soil 2.
Oil content
(%)
Maximum dry
density (g/cm3)
Optimum water
content (%)
Optimum fluid
content (%)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 1.828 11.0 11.0 85 18 67 1.8 1.804 10.4 12.2 87 19 68 3.5 1.786 9.6 13.1 90 21 69 5.3 1.756 9.0 14.3 92 22 70 7.1 1.740 7.0 14.1 94 23 71
Table D1.3: Plasticity and compaction characteristics of soil 3.
199
Oil content
(%)
Maximum dry
density (g/cm3)
Optimum water
content (%)
Optimum fluid
content (%)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 1.757 12.0 12.0 98 20 78 1.8 1.729 11.0 12.8 98 20 78 3.5 1.722 10.9 14.4 100 22 78 5.3 1.714 9.2 14.5 110 22 88 7.1 1.712 6.4 13.5 125 23 102
Table D1.4: Plasticity and compaction characteristics of soil 4.
Oil content
(%)
Maximum dry
density (g/cm3)
Optimum water
content (%)
Optimum fluid
content (%)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 1.734 13.0 13.0 123 22 101 1.8 1.712 11.4 13.2 128 23 105 3.5 1.688 11.8 15.3 130 24 106 5.3 1.680 11.4 16.7 135 24 111 7.1 1.660 10.0 17.1 135 24 111
Table D1.5: Plasticity and compaction characteristics of soil 5.
200
APPENDIX E
HYDRAULIC CONDUCTIVITY
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 0 45154 310 0.31 5 45464 10 45774 15 46084 20 46394 25 46704 30 47014 35 47324 40 47634 45 47944
Table E1.1: Quantity of flow, Q (ml) in 5 mins for soil 1 (0.0% oil content).
* Q interval (mm3) was divided by 1000 to obtain Q interval (ml).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 0 44375 230 0.23 5 44605 10 44835 15 45065 20 45295 25 45525 30 45755 35 45985 40 46215 45 46445 50 46675
Table E1.2: Quantity of flow, Q (ml) in 5 mins for soil 1 (1.8% oil content).
201
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 43565 116 0.116 10 43681 15 43797 20 43913 25 44029 30 44145 35 44261 40 44377 45 44493 50 44609
Table E1.3: Quantity of flow, Q (ml) in 5 mins for soil 1 (3.5% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 42777 14 0.014 10 42791 15 42805 20 42819 25 42833 30 42847 35 42861 40 42875 45 42889 50 42903
Table E1.4: Quantity of flow, Q (ml) in 5 mins for soil 1 (5.3% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 41334 3 0.003 20 41337 30 41340 40 41343 50 41346 60 41349 70 41352 80 41355 90 41358 100 41361
Table E1.5: Quantity of flow, Q (ml) in 10 mins for soil 1 (7.1% oil content).
202
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 40333 207 0.207 10 40540 15 40747 20 40954 25 41161 30 41368 35 41575 40 41782 45 41989 50 42196
Table E1.6: Quantity of flow, Q (ml) in 5 mins for soil 2 (0.0% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 39519 152 0.152 10 39671 15 39823 20 39975 25 40127 30 40279 35 40431 40 40583 45 40735 50 40887
Table E1.7: Quantity of flow, Q (ml) in 5 mins for soil 2 (1.8% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 30042 76 0.076 10 30118 15 30194 20 30270 25 30346 30 30422 35 30498 40 30574 45 30726 50 30802
Table E1.8: Quantity of flow, Q (ml) in 5 mins for soil 2 (3.5% oil content).
203
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 274805 8 0.008 10 274813 15 274821 20 274829 25 274837 30 274845 35 274853 40 274861 45 274877 50 274885
Table E1.9: Quantity of flow, Q (ml) in 5 mins for soil 2 (5.3% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 26111 2 0.002 20 26113 30 26115 40 26117 50 26119 60 26121 70 26123 80 26125 90 26127 100 26129
Table E1.10: Quantity of flow, Q (ml) in 10 mins for soil 2 (7.1% oil content).
204
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 25333 100 0.1 10 25433 15 25533 20 25633 25 25733 30 25833 35 25933 40 26033 45 26133 50 26233
Table E1.11: Quantity of flow, Q (ml) in 5 mins for soil 3 (0.0% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 23100 76 0.076 10 23176 15 23252 20 23328 25 23404 30 23480 35 23556 40 23632 45 23708 50 23784
Table E1.12: Quantity of flow, Q (ml) in 5 mins for soil 3 (1.8% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 22050 32 0.032 10 22082 15 22114 20 22146 25 22178 30 22210 35 22242 40 22274 45 22306 50 22338
Table E1.13: Quantity of flow, Q (ml) in 5 mins for soil 3 (3.5% oil content).
205
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 20902 4 0.004 10 20906 15 20910 20 20914 25 20918 30 20922 35 20926 40 20930 45 20934 50 20938
Table E1.14: Quantity of flow, Q (ml) in 5 mins for soil 3 (5.3% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 19000 1 0.001 20 19001 30 19002 40 19003 50 19004 60 19005 70 19006 80 19007 90 19008 100 19009
Table E1.15: Quantity of flow, Q (ml) in 10 mins for soil 3 (7.1% oil content).
206
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 29354 65 0.065 10 29419 15 29484 20 29549 25 29614 30 29679 35 29744 40 29809 45 29874 50 29939
Table E1.16: Quantity of flow, Q (ml) in 5 mins for soil 4 (0.0% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 28111 55 0.055 10 28166 15 28221 20 28276 25 28331 30 28386 35 28441 40 28496 45 28551 50 28606
Table E1.17: Quantity of flow, Q (ml) in 5 mins for soil 4 (1.8% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 28600 20 0.02 10 28620 15 28640 20 28660 25 28680 30 28700 35 28720 40 28740 45 28760 50 28780
Table E1.18: Quantity of flow, Q (ml) in 5 mins for soil 4 (3.5% oil content).
207
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 26401 3 0.003 20 26404 30 26407 40 26410 50 26413 60 26416 70 26419 80 26422 90 26425 100 26428
Table E1.19: Quantity of flow, Q (ml) in 10 mins for soil 4 (5.3% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 25055 1 0.001 20 25056 30 25057 40 25058 50 25059 60 25060 70 25061 80 25062 90 25063 100 25064
Table E1.20: Quantity of flow, Q (ml) in 10 mins for soil 4 (7.1% oil content).
208
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 23555 40 0.04 10 23595 15 23635 20 23675 25 23715 30 23755 35 23795 40 23835 45 23875 50 23915
Table E1.21: Quantity of flow, Q (ml) in 5 mins for soil 5 (0.0% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 5 22001 35 0.035 10 22036 15 22071 20 22106 25 22141 30 22176 35 22211 40 22246 45 22281 50 22316
Table E1.22: Quantity of flow, Q (ml) in 5 mins for soil 5 (1.8% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 19900 23 0.023 20 19923 30 19946 40 19969 50 19992 60 20015 70 20038 80 20061 90 20084 100 20107
Table E1.23: Quantity of flow, Q (ml) in 5 mins for soil 5 (3.5% oil content).
209
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 10 16667 2 0.002 20 16669 30 16671 40 16673 50 16675 60 16677 70 16679 80 16681 90 16683 100 16685
Table E1.24: Quantity of flow, Q (ml) in 10 mins for soil 5 (5.3% oil content).
Time (mins) Q (mm3) Q interval (mm3) Q interval (ml ) 20 15203 1 0.001 40 15204 60 15205 80 15206 100 15207 120 15208 140 15209 160 15210 180 15211 200 15212
Table E1.25: Quantity of flow, Q (ml) in 20 mins for soil 5 (7.1% oil content).
Oil content
(%)
Hydraulic conductivity (m/s)
Soil 1 Soil 2 Soil 3 Soil 4 Soil 5
0.0 3.35 x 10-9 2.24 x 10-9 1.08 x 10-9 7.02 x 10-10 4.32 x 10-10
1.8 2.49 x 10-9 1.64 x 10-9 8.21 x 10-10 5.94 x 10-10 3.78 x 10-10
3.5 1.25 x 10-9 8.21 x 10-10 3.46 x 10-10 2.16 x 10-10 1.24 x 10-10
5.3 1.51 x 10-10 8.64 x 10-11 4.32 x 10-11 1.62 x 10-11 1.08 x 10-11
7.1 1.62 x 10-11 1.08 x 10-11 5.40 x 10-12 3.60 x 10-12 2.70 x 10-12
Table E2: Hydraulic conductivity of soils.
210
APPENDIX F
PLASTICITY CHARACTERISTICS AND HYDRAULIC CONDUCTIVITY OF CONTAMINATED SOIL.
Oil content (%)
Hydraulic conductivity
(m/s)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%)
0.0 3.35 x 10-9 48 13 35 1.8 2.49 x 10-9 50 15 35 3.5 1.25 x 10-9 52 15 37 5.3 1.51 x 10-10 54 16 38 7.1 1.62 x 10-11 58 16 42
Table F1.1: Plasticity characteristics and hydraulic conductivity of soil 1.
Hydraulic
conductivity (m/s)
Liquid limit (%)
Plastic Limit (%)
Plasticity index (%) Oil content
(%) 0.0 2.24 x 10-9 73 17 56 1.8 1.64 x 10-9 74 17 57 3.5 8.21 x 10-10 76 18 58 5.3 8.64 x 10-11 77 18 59 7.1 1.08 x 10-11 78 18 60
Table F1.2: Plasticity characteristics and hydraulic conductivity of soil 2.
Hydraulic conductivity
(m/s) Liquid limit
(%)
Plastic Limit (%)
Plasticity index (%)
Oil content (%)
0.0 1.08 x 10-9 85 18 67 1.8 8.21 x 10-10 87 19 68 3.5 3.46 x 10-10 90 21 69 5.3 4.32 x 10-11 92 22 70 7.1 5.40 x 10-12 94 23 71
Table F1.3: Plasticity characteristics and hydraulic conductivity of soil 3.
211
Oil content Hydraulic conductivity Liquid limit Plastic Limit
(%)
Plasticity index (%)
(m/s) ( % )
( % ) 0.0 7.02 x 10-10 98 20 78
1.8 5.94 x 10-10 98 20 78 3.5 2.16 x 10-10 100 22 78
5.3 1.62 x 10-11 110 22 88 7.1 3.60 x 10-12 125 23 102
Table F1.4: Plasticity characteristics and hydraulic conductivity of soil 4.
Oil content (%)
Hydraulic conductivity
(m/s) Liquid limit
(%) Plastic Limit
(%) Plasticity index
(%) 0.0 4.32 x 10-10 123 22 101
1.8 3.78 x 10-10 128 23 105
3.5 1.24 x 10-10 130 24 106 5.3 1.08 x 10-11 135 24 111
7.1 2.70 x 10-12 135 24 111
Table F1.5: Plasticity characteristics and hydraulic conductivity of soil 5.
212
APPENDIX G
COMPACTION CHARACTERISTICS AND HYDRAULIC CONDUCTIVITY OF CONTAMINATED SOIL
Oil content Hydraulic
conductivity (m/s)
Maximum dry density (g/cm3)
Optimum water content
(%)
Optimum total fluid content
(%) 0.0 3.35 x 10-9 1.880 11.4 11.4 1.8 2.49 x 10-9 1.840 10.1 11.9 3.5 1.25 x 10-9 1.838 9.1 12.6 5.3 1.51 x 10-10 1.798 8.9 14.2 7.1 1.62 x 10-11 1.774 4.4 11.5
Table G1.1: Compaction characteristics and hydraulic conductivity of soil 1.
Oil content (%)
Hydraulic conductivity
(m/s)
Maximum dry density (g/cm3)
Optimum water content
(%)
Optimum total fluid content
(%) 0.0 2.24 x 10-9 1.896 11.7 11.7 1.8 1.64 x 10-9 1.839 11.0 12.8 3.5 8.21 x 10-10 1.830 9.8 13.3 5.3 8.64 x 10-11 1.775 10.0 15.3 7.1 1.08 x 10-11 1.748 7.0 14.1
Table G1.2: Compaction characteristics and hydraulic conductivity of soil 2
Oil content (%)
Hydraulic conductivity
(m/s) Maximum dry density (g/cm3)
Optimum water content
(%)
Optimum total fluid content
(%) 0.0 1.08 x 10-9 1.828 11.0 11.0 1.8 8.21 x 10-10 1.804 10.4 12.2 3.5 3.46 x 10-10 1.786 9.6 13.1 5.3 4.32 x 10-11 1.756 9.0 14.3 7.1 5.40 x 10-12 1.740 7.0 14.1
Table G1.3: Compaction characteristics and hydraulic conductivity of soil 3.
213
Oil content (%)
Hydraulic conductivity
(m/s)
Maximum dry density (g/cm3)
Optimum water content
(%)
Optimum total fluid content
(%) 0.0 7.02 x 10-10 1.757 12.0 12.0 1.8 5.94 x 10-10 1.729 11.0 12.8 3.5 2.16 x 10-10 1.722 10.9 14.4 5.3 1.62 x 10-11 1.714 9.2 14.5 7.1 3.60 x 10-12 1.712 6.4 13.5
Table G1.4: Compaction characteristics and hydraulic conductivity of soil 4.
Oil content (%)
Hydraulic conductivity
(%)
Maximum dry density (g/cm3)
Optimum water content
(%)
Optimum total fluid content
(%) 0.0 4.32 x 10-10 1.734 13.0 13.0 1.8 3.78 x 10-10 1.712 11.4 13.2 3.5 1.24 x 10-10 1.688 11.8 15.3 5.3 1.08 x 10-11 1.680 11.4 16.7 7.1 2.70 x 10-12 1.660 10.0 17.1
Table G1.5: Compaction characteristics and hydraulic conductivity of soil 5.
top related