monitoring of tabarak-abad embankment dam...
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MONITORING OF TABARAK-ABAD EMBANKMENT DAM DURING
CONSTRUCTION A. Farivar, University of Tehran, Tehran, Iran A. A. Mirghasemi, Associate Professor, University of Tehran, Tehran, Iran R. Mahin Roosta, University of Zanjan, Zanjan, Iran
ABSTRACT Tabarak-Abad dam is a clay core, earth-rock fill dam with the height of 74 m above its rocky foundation. The dam with the crest length of 193.5 m is located on the Tabarak-Abad River at north east of IRAN. Construction of the dam began on January 2003 and completed on October 2004. The dam is extensively instrumented to provide data required for monitoring. The paper will describe the instrumentation system installed in the dam body to assess the water pressure, earth pressure and deformation. With the help of information provided by different kind of instruments, the behavior of the embankment is investigated during its construction. RÉSUMÉ Le barrage de Tabarak-Abad est un noyau d'argile, barrage de suffisance de terre-roche avec la taille de 74 m au-dessus de sa base rocheuse. Le barrage avec la longueur de crête de 193.5 m est situé sur le fleuve de Tabarak-Abad au nord-est de l'IRAN. La construction du barrage a commencé en janvier 2003 et a accompli en octobre 2004. Le barrage est intensivement équipé pour fournir eus besoin pour la surveillance. L'article décrira le système d'instrumentation installé dans le corps de barrage pour évaluer la pression de l'eau, la pression de la terre et la déformation. Avec l'aide de l'information fournie par le genre différent d'instruments, le comportement du remblai est étudié pendant sa construction.
1. INTRODUCTION Tabarak-Abad dam is located at north east of IRAN on the Tabarak-Abad River, near the Ghoochan city. Length and width of the crest of dam is 193.5m and 10m, respectively (Mahab Ghods Consulting Eng. 1992). It is an earth-rock fill dam with a central clay core. The outer slopes of the dam are made of 1V:1.8H and 1V:1.65H upstream and downstream shells, respectively. The core is made of exceptionally fine clay and its slopes are 1V:0.25H in both sides. The shells of the dam are made of rock fill material. The filters act to protect the core from erosion to drain seepage water and to make a transition between the core and the shell. Volume of essential materials in different parts of the dam body is as follow: rock fill shell = 0.672e6
m3, core = 0.151e6 m3, filters = 0.06e6 m3 and transition = 0.072e6 m3 (Mahab Ghods Consulting Eng. 1993). The capacity of the reservoir at normal and maximum water level is 47.1 and 60 million cubic meters, respectively. The type of spillway is free spillway with fan shaped transition. Majority of the foundation is shale stone and the others are limestone. Six layers of shotcrete with 0.3 meters thickness along the dam length are placed between the clay core and foundation. The function of these layers is to exclude any erosion of fines from the core into the voids and joints of the foundation. Figure 1 shows the Tabarak-Abad dam at the end of construction. Also Figure 2 presents the typical cross section of the dam.
Figure1. Tabarak-Abad dam – End of construction
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1.65
3.09m
1494.55.00m 1
Lime Stone
Grouting Curtain
1.8Backfill1
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1
C.L
1
0.250.25
10.00m
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Shale Stone Lime Stone
Backfill1.651
1
Figure2. Typical cross section of Tabarak-Abad dam
P.C.9.7
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Earth Preasure Cell Cluster
Inclinometer Device
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Electrical Piezometer
Stand Pipe Piezometer
LEGEND :
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As Built Instruments Location of Section 9
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Figure3. Arrangement of instruments at section 9-9
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2. INSTRUMENTATION The safety and performance of embankment dams must be controlled during the construction, first impounding and long-term operation. In the words of ICOLD (1989b): ‘It is generally accepted that safety does not depend only on proper design and construction, but also on monitoring actual behavior during the first few years of operation and over the service life of the structure’. For this purpose the dam is equipped with measuring devices and controlling instruments for identification of displacements, pore water pressure and stresses. Instrumentation system of the Tabarak-Abad dam consists of: - 120 total pressure cells (PC) for monitoring of the total earth pressures in the dam body, - 44 vibrating wire as the electrical piezometers (EP) for monitoring of the pore water pressures in the dam body, - 21 stand pipe piezometers (SP) for manual monitoring of the pore water pressures in the dam foundation and body (often as the double check devices), - 9 inclinometers (I) for monitoring of the lateral displacements in horizontal directions and measuring the vertical displacement of the dam body at different levels, - 2 sets of extensometers for measuring the core deformation in longitudinal axis, - 7 observation wells (A.O.W), - 3 accelerographs. All of the instruments are installed in three cross sections with names of 6-6, 9-9 and 12-12. Section 9-9 is the central and largest of them, therefore; it is selected for detail investigation as presented in this paper. In this cross section there are 8 PC, 16 EP, 7 SP and 3 inclinometers installed. The locations of inclinometers are one is in the middle of core on the dam axis, another in upstream shell near the filter and the last one in downstream shell, under the berm location. This arrangement is illustrated in Figure 3. 3. MONITORING All of available data from mentioned instruments during dam construction is collected for monitoring behavior of the dam. This period of construction time is about 600 days and is less than primary anticipated time, 730 days. Available data are based on 3 sets of information, one is created pore water pressure in core material during construction, the other is deformation of dam body and the last is the total earth pressure. All of these items are studied separately. 3.1 Pore water pressure When additional earth fill is placed on the impervious zone of an embankment, at the lower part, an increase in pore pressure is resulted. Pore pressure development is controlled by the rate of embankment construction and the conditions influencing the water pressure dissipation. Measuring the induced construction pore pressure is extremely important since the data can be used to assess
the slope stability analysis during and at the end of construction. In this section the variation of pore water pressure in central core during construction is presented. Available data from electrical vibrating wire piezometers (EP) is illustrated in Figures 4 & 5. These figures show alteration of embankment level and pore water pressure (in terms of water level) against dam construction time at the lowest level (1448.3 m.a.s.l.) of clay core in section 9-9. Figure 4 includes the data for upstream piezometers and Figure 5 contains the information obtained from the piezometers installed at downstream side of the dam core axis. They show that pore water pressure in all EPs increases as long as embankment level increases. The increment of pore water pressure increasing in the central zone of the core is quite large and considerable comparing with those of installed at two sides of the clay core.
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100 200 300 400 500 600 700
Day from Base Date
LE
VE
L(m
)
EP 9-1
EP 9-2
EP 9-3
EP 9-4
Soil
Elevation
Figure 4. Alterations of embankment level and pore water pressure at EPs installed in level 1448.3 and upstream side of the core axis during the construction.
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100 200 300 400 500 600 700
Day from Base Date
LE
VE
L(m
)
EP 9-5
EP 9-6
EP 9-7
EP 9-8
Soil
Elevation
Figure 5. Alterations of embankment level and pore water pressure at EPs installed in level 1448.3 and downstream side of the core axis during the construction.
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For the instruments installed close to downstream and upstream filter, the seepage path is shorter and allows faster dissipation of pore pressure and causes less construction pore pressure. Decreasing pore water pressure at last stages of the dam construction is because of the arching phenomenon. It means that after embankment level of about 1510 m.a.s.l., no more total earth pressure is induced at the lower level of the core. As a result the development of excess pore pressure in the clay core was stopped. Instead, the previously induced excess pore pressure started to be dissipated. Figure 6 shows the induced pore water pressure at different locations of the dam core at its mid level (1473.8 m.a.s.l.) versus the construction time. The same trend can be observed here. Initiation of pore water pressure disapation after a certain level of embankment (caused by total earth pressure arching) and reduction of pore pressure by increasing the distance from the core axis.
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Day from Base Date
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VE
L(m
)
Soil
Elevation
EP 9-9
EP 9-10
EP 9-11
EP 9-12
Figure 6. Alterations of embankment level and pore water pressure (as water level) at EP installed in level 1473.8 during the construction period. Figure 7 shows the distribution of pore water pressure along the dam core (section 9-9) at its lower (1448.3) and mid (1473.8) levels at different stages of construction, in another way. Again it shows the more the distance from the core axis, the less the build up of pore water pressure. It can be seen that for both levels the maximum pore water pressure is created when the embankment is reached up to the level of 1513 meter above sea level (m.a.s.l.). This is consistent with the arching effect observed from Figures 5 & 6. The maximum induced pore water pressure is about 580 kpa in EP 9-4 which is installed at the level of 1448.3 meter in the central zone of the core. The maximum pore water pressure coefficient (Ru)max is an important factor to evaluate the pore water pressure in clay core. It is defined as follow:
max
maxu
u )(R
=
vσ
[1]
Embankment
Level
0
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600
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re
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su
re (
kp
a)
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0
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1
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2
Figure 7. Variation of measured pore water pressure at cross section 9-9 at levels 1448.3 and 1473.8 during the construction period. where u is excess pore water pressure (KN/m3) and σv is vertical total pressure (KN/m3). In this equation σv can be determined using two different methods. If σv=gh then (Ru)max is defined as ‘calculated pore water pressure coefficient’ and if σv is measured by earth pressure cells directly then (Ru)max is ‘measured pore water pressure coefficient’. In last definition arching effect is considered in σv, therefore calculated pore water pressure coefficient is less than measured one; because arching phenomenon causes reduction of measured σv with regard to calculated one. Figure 8 shows alterations of both calculated and measured maximum pore water pressure coefficient during the construction period. As can be seen, the average pore pressure coefficient at the end of construction is less than 0.5 which indicates the total stress is at least two times of water pressure in clay core. Therefore the possibility of hydraulic fracturing of clay core at first impounding is minimized.
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u)m
ax
Ru Measured Ru Calculated
Figure 8. Alterations of maximum pore water pressure coefficient during the construction period.
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The calculated and measured pore pressure coefficient at the end of construction for Karkheh dam was found to be 0.42 and 0.7 (Niroomand.2000), respectively. These values for another Iranian embankment dam, Maroon, was reported to be 0.4 and 0.8 (Mahab Ghodss Consulting Eng.2003). 3.2 Settlement Vertical movements occur as a result of consolidation of the foundations and embankment or changes in material specifications when they are subjected to saturation. Such settlement can result in cracking and slope instability. Thus it is very important to monitor all kind of movements for an embankment during its construction, impounding and operation. The settlement behavior of Tabarak-Abad dam during construction is shown in Figure 9. In this figure, variation of settlement at the location of inclinometers installed in the section 9-9 at the end of construction is plotted. It can be seen that maximum settlement which is equal to 136cm is measured at the clay core. This maximum settlement is occurred approximately at the middle height of the dam. Upstream and downstream shells have lower settlement than core, as the core material is more compressible. Also measured settlement in upstream shell is greater than downstream. Because its position is closer to the core and height of embankment is greater. As can be seen the quantity of settlement in the upstream shell is very similar to that of clay core and is greater than down stream shell. The difference in height of the dam at the locations of downstream and upstream inclinometers and also the variation of material properties may describe the differences between measured settlement of upstream and downstream shells.
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Ele
va
tio
n (
m)
Measured at Upstream Measured at Downstream Measured at the core
1521.5
Figure 9. Profile of settlement in direction of inclinometers in section 9-9 at the end of dam construction.
3.3 Total earth pressure The total earth pressures are measured in five directions by means of cluster load cells (PC). Their installed directions are horizontal, vertical with left bank to right bank direction, vertical with upstream to downstream direction, 45 degrees sloped to upstream and 45 degrees sloped to downstream. Variations of vertical total earth pressure measured by PCs in the core at cross section 9-9 at different embankment level are shown in Figure 10. Maximum total pressure of core is 1100 kpa that measured by PC 9-5 when the embankment level is 1521 at the end of construction. It can be seen that increment of total pressure at embankment level 1521 is very less than level 1512.5. It is because of arching happening at the final stage of embankment that causes no more pressure acting on the lower level of embankment. This phenomenon was shown in the previous figures as well.
Embankment
Leve
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rtic
al
Pre
ss
ure
(K
Pa
)1482
1493
1505
1512.5
1521
Up Stream Down Stream
PC 9-1
PC 9-2 EP 9-3
PC 9-4
PC 9-5
PC 9-6
Figure 10. Variation of vertical total earth pressure measured by PC in the core at cross section 9-9 at different embankment levels.
All of the PCs are installed in the cluster cells in five directions and measure the total soil pressure perpendicular to its direction. Among the all PCs installed at level 1448.3 of section 9-9, PC 9-3 and 9-4 are in the central zone of the core. Figures 11 and 12 show the alterations of measured total pressure at cluster PC 9-3 and 9-4, respectively. Both figures show the total pressures at five directions perpendicular to installed cell direction. As can be seen, horizontal cells that show vertical pressures have the greater pressure than the other directions. Those pressure cells which have vertical directions and show horizontal pressures, approximately measure the same quantity of pressures. The two pressure cells that have 45 degrees orientation to upstream and downstream, show similar behavior. The reason is the dam symmetric geometry which led to the symmetric total earth pressure distribution at the end of construction.
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PC 9-3
0
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16
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Day from base Date
To
tal
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ess (
kg
/cm
2)
PC 9-3-1(Vertical
with Left Bank
to Right Bank
Direction)
PC 9-3-2(45
Degrees Sloped
to Upstream)
PC 9-3-3
(Horizontal)
PC 9-3-4(45
Degrees Sloped
to Downstream)
PC 9-3-5(Vertical
with Upstream
to Downstream
Direction)
Embankment
Figure 11. Measured total earth pressure at cluster PC 9-3 during the construction time.
PC 9-4
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8
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tal
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s (
kg
/cm
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PC 9-4-1(Vertical
with Left Bank to
Right Bank
Direction)
PC 9-4-2(45
Degrees Sloped
to Upstream)
PC 9-4-3
(Horizontal)
PC 9-4-4(45
Degrees Sloped
to Downstream)
PC 9-4-5(Vertical
with Upstream to
Downstream
Direction)
Embankment
Figure 12. Measured total earth pressure at cluster PC 9-4 during the construction time.
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2
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6
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Day from base Date
To
tal
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ss
(kg
/cm
2)
PC 9-1-3
PC 9-2-3
PC 9-3-3
PC 9-4-3
PC 9-5-3
PC 9-6-3
Embankment
Figure 13. Vertical total earth pressure in level 1448.3 versus construction time.
Figure 13 shows the alterations of measured vertical total pressure at horizontal PC installed in level 1448.3 along with the embankment surcharge (calculated based on embankment height and its specific gravity). As it can be seen in this figure PC 9-6-3 has measured lower quantity of earth pressure comparing to the PC 9-1-3. Because of the dam geometry, this is not reasonable and may be occurred as a result of improper functioning of the instruments.
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0.1
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0.9
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-25 -20 -15 -10 -5 0 5 10 15 20 25
Distance from Dam Axis (m)
Arch
ing
Co
effic
ien
tUp Stream Down Stream
Figure 14. Variations of arching coefficient in the core at cross section 9-9 at the end of construction period. Arching phenomenon in the clay core is evaluated by arching coefficient (AC). It is defined as follow:
h. AC vγ
σ= [2]
where σv is the measured earth pressure by PCs. The less AC, the more arching effect. Ultimately, Figure 14 shows the variations of arching coefficient in the core at cross section 9-9 at the end of construction period. As can be seen the average AC is about 0.75 at the middle zone of the clay core. This quantity in the other embankment dams in IRAN such as Karkheh and Maroon embankment dams are about 0.46 (Niroomand.2000) and 0.4 (Mahab Ghods Consulting Eng.2003), respectively. So arching effect in Tabarak-Abad dam is less than these two embankment dams. In fact arching phenomenon is not critical in this project.
4. CONCLUSION
This paper describes the instrumentation installed in the Tabarak-Abad embankment dam and monitors the data obtained from the measurements. The result of this study indicates the appropriate function of instrumentation system. It seems that overall the instruments work well, except EP 9-8 and PC 9-6. They are located at the similar zone near the downstream filter. This might be because of the improper installation of the instruments or may be due to the occurrence of local arching.
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Most figures show that the total earth pressure distribution in the clay core is influenced by the arching phenomenon. This appears from the fact that builds up of earth pressure at the lowest level of the core ends at a certain embankment height when the construction is still under progress. Also the excess pore water pressure starts to dissipate before the completion of the embankment. In other words, since the total stress is measured to be constant at a certain construction stage, no more construction pore pressure is developed and the consolidation process causes the reduction of pore water pressure. References
CIGB-ICOLD, 1989, Dam Monitoring General Consideration, BULLETIN 60.
Mahab Ghods Consulting Eng, 1992, The report of design body of Tabarak-Abad Embankment Dam, Technical report, Tehran-Iran.
Mahab Ghods Consulting Eng, 1993, The report of materials construction of Tabarak-Abad Embankment Dam, Technical report, Tehran-Iran.
Mahab Ghods Consulting Eng, 2003, Evaluation of Stability Condition of Maroon Dam, Technical report, Tehran-Iran.
Niroomand, H, 2000, The evaluation of Karkheh behavior during construction according to instrumentation records, MSc. thesis submitted in the Faculty of Engineering, University of Tehran.
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Pages892-996.pdfPaper 95.pdf1. INTRODUCTION4. CONCLUSIONSREFERENCES
Paper 502.pdfPOLYETHYLENE GEOMEMBRANES SURFACE TEXTURESHEAR-STRENGTH PROPERTIESDefinitionsDesigning with shear strength properties - OverviewSpecification of interface shear strength properties
EXPERIMENTAL PROGRAMGeomembrane – geotextile interfacesGeomembrane –soils interfacesGeomembrane – sand interfaceGeomembrane – clay interface
DISCUSSIONFactors influencing the shear resistancePeak versus residual shear strength
CONCLUSIONSRECOMMENDATIONSREFERENCES
Paper 288.pdf5. REFERENCES
Paper 536.pdfINTRODUCTIONMETHODOLOGYRESULTS AND DISCUSSIONPreliminary filtration tests
5. ACKNOWLEDGEMENTS
Paper 347.pdfINTRODUCTIONMETHODOLOGYMSW Characterization for Elastic Properties and ProportionsFinite Element “Unit Cell”Stochastic Modelling using the Monte Carlo MethodInterpretation of Results
RESULTS AND DISCUSSIONCONCLUSIONS
Paper 452.pdfINTRODUCTIONREMEDIAL ACTION PLANPrevious Use of PermanganatePermanganate Injection ConfigurationPermanganate Demand
OPERATIONAL RESULTSOperational Results - 2004Operations ModificationsOperational Results – 2005
CONCLUSIONSACKNOWLEDGEMENTS
Paper 399.pdfINTRODUCTIONVIBRATION IMPACT ASSESSMENT CRITERIAFIELD MEASUREMENTSSite ConditionsMeasuring Equipment/ProceduresPre-Construction MeasurementsConstruction Measurements
DISCUSSIONACKNOWLEDGEMENTS
Paper 292.pdfINTRODUCTIONTHEORETICAL BACKGROUNDDIELECTRIC BASED PROBESMATERIALS USED AND TESTING METHODSTEST RESULTSCalibration for CS616 probesCalibration for ML2x and SM200 probesComparison between measured and predicted water contentSoil density effectTemperature effectElectrical conductivity
FIELD APPLICATIONSCONCLUSIONSACKNOWLEDGEMENTS
Paper 296.pdfABSTRACTINTRODUCTIONMETHODOLGYBONE CREEK SITERegional GeologySurficial Geology and TerrainGroundwater Conditions
CENTENNIAL SITERegional GeologySurficial Geology and TerrainGroundwater Conditions
FOUNDATION CONDITIONSCONCLUSIONSACKNOWLEDGEMENTS
Paper 245.pdfINTRODUCTIONSURFICIAL GEOLOGYClearwater Formation (Clay Shale)McMurray Formation (Oil Sand)
TEST FILLIntroductionConfigurationInstrumentationConstruction and Monitoring Program
FOUNDATION PERFORMANCESlope inclinometersPiezometersSurveyPerformance Summary
ACKNOWLEDGEMENTSREFERENCES
Paper 320.pdfINTRODUCTIONSITE DESCRIPTIONSite Location and HistoryNew Silo Layout and Loading ConditionsSoil Conditions
SETTLEMENT OF EXISTING STRUCTURESSurvey DataEvaluation of Settlement Data
SETTLEMENT ANALYSIS METHODOLOGY FOR PROPOSED NEW CEMENT AND FLY ASH SILOSSettlements due to Elastic CompressionSettlements due to Primary ConsolidationSecondary Consolidation Settlement
ANALYSIS RESULTS FOR PROPOSED CEMENT AND FLY ASH SILOSCONSTRUCTIONCONCLUSION
Paper 395.pdfINTRODUCTIONBEARING CAPACITY EQUATIONS FOR CRAWLER CRANESBasic DimensionsSimplificationsProposed Bearing Capacity Equations
CASE STUDYSubsoil ConditionsCrane and Mats LayoutField ObservationCrane Track Pressure DeterminationComputer ModellingBearing Capacity Calculation
CONCLUSIONACKNOWLEDGEMENTS
Pages997-1111.pdfPaper 463.pdfPaper 463.pdfINTRODUCTIONHistory of Development and Natural Hazard ImpactsSite Conditions Prior to 1987
EVOLUTION OF AVALANCHE /DEBRIS FLOW EVENTSIncrease In Events That Impacted the RailwayAvalanche and Debris Flow Path in 1984 Prior to Defence WorksFlow Path Modification Prior to 1984 Due to Frozen Cap Wasting
AVALANCHE HAZARD CHARACTERIZATIONObserved Avalanches and Impact on the RailwayThe Design Avalanche
DEBRIS FLOW HAZARD CHARACTERIZATIONDesign Flow EventsDesign Debris Flow
AVALANCHE AND DEBRIS FLOW DEFENCE WORKSDesign RequirementsSelected Design of ChannelConstruction
PERFORMANCE OF THE DEFENCE WORKSINFLUENCE OF CLIMATE CHANGECONCLUSIONSACKNOWLEDGEMENTS
Paper 256.pdfINTRODUCTIONSLOPE STABILTY MANAGEMENT MODELSLOPE STABIILITY ANALYSESTopography and surface geometryStratigraphy or layers of different materialsEngineering properties of materials for each layerHydraulic conditions in the layers (porewater pressure)Sensitivity Analysis
INSTRUMENTATIONRISK MANAGEMENT SYSTEMFUTURE PLANNINGSUMMARY
Paper 552.pdfINTRODUCTIONDESCRIPTION OF DECANT SYSTEMINFLOW EVENTMECHANISM FOR INFLOWNATURAL PLUGGING OF CRACKSWATER QUALITY MONITORINGDECISIONSCONCLUSION
Paper 376.pdfINTRODUCTIONTHERMAL PROPERTIESThermal ConductivityHeat Capacity
AIR BUFFEREMBANKMENTEffect of Air PermeabilityEffect of Thermal ConductivityEffect of Air Boundary Conditions
CONCLUSIONSACKNOWLEDGEMENTS
Paper 383.pdfINTRODUCTIONTEST METHOD AND MATERIALSALINITY REDISTRIBUTIONSTRENGTH AND SALINITY DISTRIBUTIONCONCLUSIONACKOWLEDGEMENTS
Paper 546.pdfINTRODUCTIONObjectives
ARD GENERATION AND MITIGATIONARD GenerationCommon ARD mitigation measures
CASE STUDIESCharacteristics of Polymers and Polyethylene (PE) and Polypropylene (PP) GeosyntheticsCharacteristics Geosynthetic Clay Liners (GCLs)Case Studies of Field Installations of Geosynthetics to Mitigate ARDLLDPE Capping of ARD waste rockHDPE Cover System over TailingsUse of PE in Heap LeachingGCL Cover on Apache TailingsGCL Cover on Zortman Landusky Suprise Pit (Olsta and Friedman 2002)
Case Studies regarding the Performance Evaluation of Geosynthetics to Mitigate ARDEffects of synthetic ARD on Polymer Properties (Gulec et al. 2004, 2005)Performance of a Soil Cover Systems containing GCLs in a temperate climate (Melchoir 2002)Performance of a soil cover systems containing a GCL in a humid climate (Renken 2006)GCL desiccation below a geomembrane (Southen 2005)Metal Migration in GCLs (Lange et al. 2004)
DISCUSSIONSUMMARY
Paper 197.pdfINTRODUCTIONMATERIALS TESTEDLARGE SCALE DRYING TESTSTest SetupResultsGold TailingsSilicate Tailings
SMALL SCALE DRYING TESTSTest SetupTest ResultsGold TailingsSilicate 1Silicate 2
SHRINKAGE TESTINGTest ProceduresResults
INTERPRETATION OF RESULTSCONCLUSIONS
Pages1112-1220.pdfPaper 534.pdfINTRODUCTIONSITE LOCATIONSTESTS AND MEASUREMENTSRESULTS AND DISCUSSIONCONCLUDING REMARKS
Paper 539.pdfINTRODUCTIONDESCRIPTION OF THE SAMPLERDESCRIPTION OF THE FLUMEFlow characteristics in the flumeDescription of the sample holderDescription of sampling sitesSediment deposit samples were collected at two locations in Hamilton Harbour (Figure 6).Testing of sediment cores in the flumeThe sediment cores were tested in the flume for erosional stability and erodibility. To begin the test, a sediment core samplFigure 8. Concentration of eroded sediment as a function of time for different shear stress steps- core from Site 1.Figure 9 Concentration of eroded sediment as a function of time for different shear stress steps-core from Site 2.
RESULTS AND DISCUSSIONCritical shear stress and average erosion ratesThe data shown in Figures 8 and 9 are useful for determining the critical shear stress for erosion of the top layer of the sed(1)Dry density profiles and depths of erosionTo examine the variability in the density profiles of the sediment deposits, density measurements were made for the two cores Figure 11. Dry density profiles for the two sediment deposit samples.The density in the top 5 mm of the deposit was not measured because of the limitation of the instrument and hence it has to beTable 1: Summary of computed results for Site 1Shear stressDura-tionAmo-untDen-sityDepthCum0.21302.210.390.00020.00020.275010.40.400.00080.00100.33506.620.410.00050.00150.395010.40.420.00090.00240.46706.200.430.00050.0029Table 2: Summary of computed results for Site 2Shear stress(Pa)Dura-tion(min)Amo-unt(gm)Den-sity(g/cc)Depth(mm)Cum(mm)0.21303.900.390.00030.00030.27503.000.400.00020.00050.33500.470.400.00000.00050.39508.000.400.00070.00120.46801190.430.00970.0109From these two tables we can see that the computed depth of erosion values are only a fraction of a millimetre and are signifi
SUMMARY AND CONCLUSIONSA new sampling device to collect undisturbed sediment cores in a water body was deployed in Hamilton Harbour, Ontario, Canada.
ACKNOWLEDGEMENTS
Paper 537.pdfINTRODUCTIONWATERSHED INTEGRATED APPROACHRESULTSDISCUSSION AND CONCLUSIONSACKNOWLEDGEMENTS
Paper 559.pdfINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONSAdsorption CharacteristicsAdsorption Capacity for Zn in ARDAdsorption and Desorption Kinetics
pH Stability of CliniptilolitePerformance of Clinoptilolite in Cyclic Desorption/ Adsorption with EDTA and NaClMorphology Study of Clinoptilolite before and after Cyclic Adsorption/DesorptionExploration of a Slurry Bubble Column for Heavy Metal Capture and RegenerationAdsorption TestsDesorption Tests
CONCLUSIONS AND RECOMMENDATIONSACKNOWLEDGEMENTS
Paper 172.pdfINTRODUCTIONLANDFILL CAPS AND CLOSURESDESIGN IN LANDFILL CAPSThe bentonite ComponentThe geotextile componentsThe geosynthetic Clay liner
HYDRAULIC PROPERTIESGas Permeability
SHEAR STRENGTHLONGTERMSUMMARYREFERENCES
Paper 268.pdfINTRODUCTIONINFILTRATION SPECIMENSMIP AND SEM SPECIMEN PREPARATIONSEM AND MIP RESULTSSEM ResultsMIP Results
DISCUSSION AND INTERPRETATIONChange in Pore Size DistributionEvidence for Decreasing Conductivity
CONCLUSIONSACKNOWLEDGEMENTSREFERENCES
Paper 284.pdfINTRODUCTIONINTERNAL INSTABILTY ASSESSMENT METHODS2.1LUBOCHKOV (1965)2.2KEZDI (1969), LOWE (1975) & SHERARD (1979)2.3DE MELLO METHOD (1975)2.4KENNY & LAU (1985, 1986)BURENKOVA (1993)COMPARISON OF THE DIFFERENT METHODSINTERNAL INSTABILTY ANALYSIS OF SOME ALLUVIAL SEDIMENTSSUMMARY AND CONCLUSIONREFRENCES
Paper 379.pdfINTRODUCTIONPROJECT OVERVIEWSITE SELECTION AND APPROVALSRegulatory Approvals
FIELD PROJECT DESIGN CONSIDERATIONS AND CONSTRUCTION DETAILSFUTURE WORK AND OPERATIONAL DETAILSLiner Sampling
SUMMARY AND CONCLUSIONSACKNOWLEDGEMENTSREFERENCES
Paper 526.pdfINTRODUCTIONStatement of the Issue at-handCase History Involving a Preliminary Cover Design
NUMERICAL MODEL FOR PRELIMINARY COVER DESIGNModel DescriptionModeling SoftwareModel Inputs
CLIMATIC INPUTS FOR THE NUMERICAL MODELSPrecipitationEvaporation
MATERIAL PROPERTIES FOR THE NUMERICAL MODELSSoil Properties
RESULTS OF THE NUMERICAL MODEL SIMULATIONSIMPORTANCE OF THE RELATIONSHIP BETWEEN ALL UNSATURATED SOIL PROPERTY FUNCTIONSCHALLENGES OF THE PRELIMINARY MODELING EXERCISEDISCUSSION OF THE RESULTS OF THE NUMERICAL MODELING EXERCISECONCLUSIONS OF THE STUDY
Paper 371.pdfINTRODUCTIONCOMPARISON OF THE TWO METHODSThe Method of KezdiThe Method of Kenney and LauSynthesis of the Methods
APPLICATION OF THE METHODSGap-graded SoilsWidely-graded Soils
DISCUSSIONCONCLUSIONS
Paper 209.pdfINTRODUCTIONOVERVIEWThe multilaminate conceptSampling planesSoil anisotropyBonding and destructuration affect
MULTILAMINATE CONSITUTIVE MODELElastic behaviourSampling planesMicrostructure tensorYield surface and potential functionHardening rule
IMPLEMENTATION INTO PLAXISCODE CALIBRATIONSpatial integration frameworkEffect of model parameters
CONCLUSIONACKNOWLEDGEMENTS
Pages1221-1344.pdfPaper 189.pdfINTRODUCTIONMETHODOLOGYRESULTS AND DISCUSSIONCONCLUSIONACKNOWLEDGEMENTSREFERENCES
Paper 204.pdf1. INTRODUCTION2. INHERENT ANISOTROPY4.1.Post liquefaction �(� and �(� Relationships4.2. Comparison of Post�liquefaction Correlations4.3.Pre liquefaction �(� and �(� Relationships5.1. J-Pit5.2. Sullivan Mines
Paper 352.pdfINTRODUCTIONDETAILS OF THE CASE STUDYFINITE ELEMENT BACK ANALYSISAssumptionsSimulation of Construction StagesDetails of the Back Analyses
RESULTSAnalysis CAL-DAnalysis CAL-SAnalysis SIM-OAnalysis SIM-MAnalysis SIM-NTAnalysis SIM-C
PARAMETRIC STUDYEffect of Change in Soil StiffnessEffect of change in stiffness of retaining wall
CONCLUSIONSACKNOWLEDGEMENTSREFERENCES
Paper 409.pdfINTRODUCTIONNUMERICAL SIMULATIONUSED PROGRAMDEFINITION OF SHEAR BAND STRUCTUREINTERPRETATION OF CHARTS
EXPERIMENT DETAILSRESULTS AND DISCUSSIONSAMPLE GRADINGAVERAGE GRAIN DIAMETERPARTICLE ECCENTRICITYPOROSITYLOADING RATECONFINING PRESSURE
ConclusionReferences
Paper 490.pdf2.1Model Box CulvertCentrifuge Test Procedure3.CENTRIFUGE TEST RESULTS4.DISCUSSIONCONCLUSIONS
Paper 565.pdf7.CONCLUSIONS8.ACKNOWLEDGEMENTS
Paper 500.pdf1 INTRODUCTION
Paper 362.pdfINTRODUCTIONMETHODOLOGYRESULTSAquifer sensitivityAquifer vulnerability
CONCLUSIONS
Paper 331.pdfINTRODUCTIONWELL VULNERABILITYVULNERABILITY MAPS FOR MULTIPLE WELLSVULNERABILITY MAPS FOR THE MANNHEIM WELL FIELDCONCLUSIONSACKNOWLEDGEMENTS
Paper 135.pdfINTRODUCTIONOKANAGAN VALLEYAQUIFER VULNERABILITYDRASTICDRASTIC CharacteristicsDepth to WaterNet RechargeAquifer MediaSoil MediaTopographyImpact of Vadose ZoneHydraulic ConductivityDRASTIC Vulnerability Rating
Discussion and Ongoing WorkValidation of Vulnerability MapsAlternate Vulnerability Models - AVI
APPLICATION OF VULNERABILITY MAPS IN A SUSTAINABLE COMMUNITY DESIGN PROCESSThe Smart Growth on the Ground ProcessLand Use Allocation Model (LUAM)
ACKNOWLEDGEMENTSREFERENCES
Paper 342.pdfINTRODUCTIONBACKGROUNDGeographic setting
Figure 1. Geographic setting of the Toluca Basin with respect to the State of Mexico and the Republic of Mexico.ClimatePrecipitationTemperatureEvapotranspirationInfiltration
GeologyPopulation density
HYDROGEOLOGY AND GROUNDWATER EXPLOITATIONRegional flowGroundwater extractionWater balance in the Toluca ValleyRegional depletion of groundwater levels and reversal of vertical hydraulic gradients
LAND SUBSIDENCEBackground of subsidence in the Toluca ValleyTheoryOngoing work
CONCLUSIONSACKNOWLEDGEMENTSReferences