soil characterization and evaluation w mexico14 moh's hardness scale 40-15 amount of soil used...

AFWL-TR-83-97 AW-R

I~~4.I83-97

00 SOIL CHARACTERIZATION AND EVALUATION110AT W IESANDS MSIERANGE, NE MEXICO

Edward L. MillerRobert J. Maika

October 1983

Final Report

Approved for public release; distribution unlimited.

DTICNOV 1 8 1983

VE E TC1. VAIR FORCE WEAPONS LABORATORY

% -: Air Force Systems CommmandLAA Kirtland Air Force Base, NM 87117

83ii18 065%

AFWL-TR-83-97

This final report was prepared by the Air Force Weapons Laboratory, KirtlandAir Force Base, New Mexico, under Job Order 672A0850. Major Robert J. Majka(NTED) was the Laboratory Project Officer-in-Charge.

When Government drawings, specifications, or other data are used for anypurpose other than in connection with a definitely Government-related procure-ment, the United States Government incurs no responsibility or any obligationwhatsoever. The fact that the Government may have formulated or in any waysupplied the said drawings, specifications, or other data, is not to be regardedby implication, or otherwise in any manner construed, as licensing the holder,or any other person or corporation; or as conveying any rights or permission tomanufacture, use, or sell any patented invention that may in any way be relatedthereto.

This report has been authored by employees of the United States Government.Accordingly, the United States Government retains a nonexclusive, royalty-freelicense to publish or reproduce the material contained herein, or allow othersto do so, for the United States Government purposes.

This report has been reviewed by the Public Affairs Office and is releasableto the National Technical Information Services (NTIS). At NTIS, it will beavailable to the general public, including foreign nations.

If your address has changed, if you wish to be removed from our mailinglist, or if your organization no longer employs the addressee, please notifyAFWL/NTED, Kirtland AFB, NM 87117 to help us maintain a current mailing list.

This technical report has been reviewed and is approved for publication.

RO2" TMajor, USAFProject Officer

FOR THE COMMANDER

TILLMAN D. MCCARSON N W.Lt Colonel, USAF C lonel, USAFChief, Technology Branch ief, Civil Engineering Research Div

.4

DO NOT RETURN COPIES OF THIS REPORT UNLESS CONTRACTUAL OBLIGATIONS OR NOTICEON A SPECIFIC DOCUMENT REQUIRES THAT IT BE RETURNED.

.4

,

44

UNCLASSIFIEDSECURI7Y '.ASSIFICATICN O T-IS PAGE 'When Daree Frered)

REPORT DOCUO PREAD INSTRCT:L..N Z.REPORT DOCUMENTATION PAGE I BEFORE CO.PLET!NC, FOR'.M

1. REPORT NUMBER iz. Goff &CjESSION NO.i

A=.IP"ENT'S -ATA .; *, iB; R

A\P4L -TR -33-9 _______________

4. TITLE eand Subtitle) 5. TYPE OF REPORT & PERIO: 3VEREO

SOIL CHARACTERIZATION AND EVALUATION AT Final ReportWHITE SANDS MISSILE RANGE, NEW MEXICO

S. PERFORMING 01G. REPOPT NUMBER

7. AUTmOR(s) S. CONTRACT OR SRANT NUM9EPs /

Edward L. MillerRobert J. Majka

. PERFORMiNG O.GANIZATION NAVE ANO A0ORESS 10. POG=AtA ELEUEN. nROjET. -25K

AREA & *ORK L.',4iT %.MBEgS

Air Force Weapons Laboratory (NTED)Kirtland Air Force-Base, NM 87117 64312F/672A0850

I1. CONTROLLING OFFICE NAME AND ADORESS 12. REPORT OATE

Air Force Weapons Laboratory (NTED) October 198313. -AUMBER OF DAGESKirtland Air Force Base, NM 87117 204, .'.204

'4. MONITORING AEN;.Y NAME & ,OOpESSrif filterent from Controllina Offce) 1S. SECURITY CLASS. f'ol rhi rrport)

Unclassified158. OECLASSIF ICATION DOWNGRADING

SCHEDULE

"6. OISTRiBUTION STATEMENT (of this Peport)

Approved for public release; distribution unlimited.

17. DISTRIBUTION STATEMENT (of the abstract enered in Block 20, if different from Report)

18. SUPPLEMENTARY NOTES

This report was submitted to the College of Engineering, University ofNew Mexico to fulfill degree requirements.

19. KEY WORDS (Continue on reverse side if necessary and identify by block number)

Soil Characterization Grain Size Distribution Seismic Velocity-. White Sands Missile Range Mill Race Soil Stress

Soil Chemistry Misty Castle Series Atomic Absorbance TestTriaxial Compression Test Pre-DIRECT COURSEUnconfined Compression DIRECT COURSE

20. ABSTRACT (Continue on reverse side if necessary and identify by block number)

' complete site characterization of the subsoil conditions down to 10 meters (32feet) was conducted at White Sands Missile Range, New Mexico. This includedtesting 54 borehole samples and 6 trench bulk samples for grain-size distributionAtterberg Limits, natural and hygroscopic moisture contents, and specificgravities. Trench bulk samples were also tested for Standard Proctor maximum drydensities and optimum water contents, unconfined compressive strengths, and tri-axially-confined compressive strengths. Additional tests were performed in the

(Over)DID r 0RM 1473 EDITION OF I NOV 65 IS OBSOLETE

SCT UNCLASSIFIED". SECURITY CLASSIFICA•'ION OF THiS PAGE t "sn Data Entered)

. - * - .-%- % , . . , , 7 , . . , . . . . . .

UNCLASSIFIEDSECURITY CLASSIFICATION OF THIS PAGE(1,he Doe Entered)

20. ABSTRACT (Continued).

-,.field to include downhole nuclear density gauge measurements, standard penetra-tion tests, and seismic refraction surveys. Atomic Absorbance tests and X-raydiffraction tests were conducted in the laboratory to determine concentrationsand nature of calcium and magnesium in the soil. Correlations between strengthvalues and cementation of soil particles was established as well as correlationsbetween strength properties and seismic refraction measurements.,

UNCLASSIFIEDSM.; MTY CL ASSIFICATO#. Or A.G";~r *r Dot Em~e,

...

ACKNOWLEDGEMENTS

This project was directly supported by the Air Force Weapons Laboratory(AFWL) personnel and funds. The authors wish to express their appreciation tothe AFWL staff, particularly Mr Eric Rinehart and secretaries Lori, Eva,Eleanor, and Lynn; to Mr Dave Bedsun (CERF) who provided equipment and tech-nical expertise in all field tests performed; to Professor John B. Carney, Jr.for his supervision and assistance in the completion of this project; and tothe wives, Kathy and OK Sun, who endured the late nights of study and separa-tions during site visits to White Sands Missile Range.

Laboratory research was conducted in the soils and sanitation laboratoriesat the University of New Mexico. Professor Bruce Thompson and Ron Methanyprovided valuable assistance in the field of soil chemistry and X-ray diffrac-tion tests.

In addition, the authors wish to thank MSgt John E. Miller (ret) for hisoutstanding technical assistance in the soils laboratory and support in the

field of chemistry.

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TABLE OF CONTENTS

Section Page

I INTRODUCTION 1

II FACT-FINDING SURVEY 2

1. Library Search 22. Site Survey 2

III PRELIMINARY SUBSOIL EXPLORATION 4

1. Borehole Samples 42. Standard Penetration Test 43. Downhole Nuclear Density Gauge 44. Testing Procedures 5

A. Sample Preparation 5B. Grain-Size Distribution 5C. Specific Gravity 6D. Consistency Limits 6E. Soil Classification 7

IV DETAILED SUBSOIL EXPLORATION 8

1. Trench Bulk Samples 8

A. Field Sampling 8B. Testing Procedures 8

2. Seismic Survey 83. Standard Proctor Test 8

4. Unconfined Compression Test 95. Triaxial Compression Test 9

V TESTING RESULTS 11

VI DISCUSSION OF RESULTS 34

VII CONCLUSIONS 36

VIII EFFECTS OF CALICHE ON STATIC STRENGTH PROPERTIES 37

IX SUBSURFACE SEISMIC INVESTIGATIONS 59

Appendix A: Grain-Size Distribution Curves 140

Appendix B: Unconfined Compression Tests on Soil 165Samples Air-Dried From Various InitialWater Contents

.. . .°. . . .- ... -. . . .. . .-. -. .. . . ... ... ..- . . . - .-.. - ~ . • . . . . - .-

(Table of Contents Continued)

Appendix C: Unconfined Compression Tests on Soil 170Samples at Various Water Contents

Appendix D: Triaxial Compression Tests on Air- 175Dried Soil Samples

Appendix E: Triaxial Compression Tests on Soil 182Samples at Various Water Contents

Appendix F: Site Plan, White Sands Missile Range 195Survey Area

REFERENCES 197

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41"

I - . -.I. . . . . . . .

LIST OF FIGURES

Figure Page

I Photograph - Soil Particles; T-1 (4-5 feet). 50

2 Photograph - Soil Particles; T-1 (8.5-9.5 feet). 51

3 Photograph - Soil Particles; T-1 (12-13 feet). 52


5 Photograph - Soil Particles; T-2 (8.5-9.5 feet). 54


7 Determining Depths ha, hb, and hp. 62

8 Seismic - Time Versus Distance. 63

9 Seismic - V2 Plot. 64

10 Seismic Calculations. 65

11 Irregular Underlying Surfaces. 67

2"..

. . . . .. *

TABLES

Table Page

1 Field Identification of Soil 12

2 Standard Penetration Test Correlations 16

3 In-Situ Densities 18

4 Grain-Size Distribution 20

5 Particle Size Percentages 26

6 Soil Samples Identification Data 27

7 Soil Classification 29

8 Compaction Data 30

9 Unconfined Compression Data 31

10 Triaxial Compression Data 32

11 Calcrete Formation 38

12 Seismic Velocities of Subsurface Calcrete 39

13 Interpretation of Penetration Resistance 40

14 Moh's Hardness Scale 40

- 15 Amount of Soil Used in Samples 42

16 Atomic Absorbance Results-Standards 46

17 Atomic Absorbance Results-Samples 47

* 18 Concentrations in Samples 48

19 Actual Concentrations - Soil 49

20 Seismic Velocities of Various Types of Caliche 60

. 21 Typical Seismic Velocities for Soils and Rock 60

22 Seismic Results - Velocities 66

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SECTION I

INTRODUCTION

The United States Air Force, and on a local level the Air Force WeaponsLaboratory (AFWL) at Kirtland AFB, have on-going programs for research andtesting of various weapons effects. Specifically, AFVL is interested in the

response of strategic structures, in and around various soils, to airblast andground shock loadings.

The material characteristics needed for effective design and evaluation ofweapon systems and effects in this context are: material index properties;grain-size distribution; specific weight; poisson's ratio; deformation versusstrength properties; compressibilities; and failure envelopes. Additionally,the dynamic characteristics of soil as a function of impulse loads would bebeneficial in correlating the effects of initial shock loadings.

The purpose of this study is to investigate and evaluate the subsoil con-ditions in and around the Mill Race site located at White Sands Missile Range(WSMR), New Mexico. The intent is to characterize the subsoil to a depth of 10meters (approximately 33 feet) within an area of 2.59 kilometers square (1square mile) with Mill Race site at the center. Due to time, equipment, andcost considerations, it was impractical to investigate all parameters required,within the confines of this project. As a result, an effort was made to provideas many of the parameters as feasible, which includes material index properties,grain-size distribution, specific gravities, densities, and deformation versusstrength properties.

Due to the scope, this project was undertaken by two Air Force graduatestudents. To provide separate areas of research, each student worked on anadditional investigative area. These topics are covered under separate sectionswithin this report. They include subsurface seismic investigations and theeffects of caliche on static strength parameters.

d.

w1

SECTION II

FACT-FINDING SURVEY

1. LIBRARY SEARCH

Prior to visiting the WSMR site, technical reports, geologic index maps,topographic maps, and physiographic publications were reviewed. This litera-ture provided information which assisted in selection of the actual site.Topography and geology of the region indicated the portion of the range underconsideration to be primarily alluvial plains and playas. Possible igneous ormetamorphic rock outcrops could be present due to early volcanic activity inthe surrounding mountain region. Due to past wet periods followed by the pre-sent semi-arid climatic conditions, much of the area was formed by discreperiods of deposition. As a result, the subsoil tends to be a layered s; -'

of alluvial and other sedimentary deposits. Average particle sizes to b,expected are generally silt-size to sand, since the larger sizes were delsited closer to the alluvial fans and mountain areas. Actual thicknessef -

alluvial layers could vary from several meters to hundreds of meters,depending on their nature of deposition. High winds are prevalent in th.and also affect the layer thicknesses and composition. The leaching of a.cementation by calcium carbonate is also prevalent in this area. Actualcementation can vary from individually coated particles to thick sheets ofcaliche. The natural water table is located 60-90 meters (200-300 feet) belowground.

Topography of the area is indicated as relatively flat. Due to the pre-

sence of old playas and erosion channels, elevations tend to vary over smallareas. Swales are common and may reach depths of 3-8 meters (9-24 feet). Thearea is extremely dry with some periods of sudden storms. Vegetation issparse and mostly cactus and yucca trees. The actual Mill Race site is leveland has been brought back to grade (after the initial MILL RACE test) by theaddition of backfill and ejecta (material thrown from the crater after blast).

With this knowledge of local site conditions, and several reports on iso-lated seismic/borehole investigations, a preliminary decision was made to usethe Mill Race site as the center of the area to be characterized. Thismatched plans for future projects as well as the key concern of having relati-vely level terrain in test regions.

2. SITE SURVEY

Several visits were made to the site prior to performing any field testingor sampling. The initial visit included a walk-through of the entire areaunder consideration. Possible areas of conflict were identified, such as deepswales and existing structures, which could interfere with testing operations.Based on existing road patterns and general topography, the actual area of2.59 kilometers square was adjusted to lie with its western edge along Route13 (primary compacted dirt road). This placed GZ-3 (MILL RACE site) near thecenter, slightly southeast.

The next series of visits were used to survey the area and locateintended boreholes. A geodetic survey marker (Defense Mapping Agency SurveyBrass Plate/Douquette RN 1/DNA 10/1978), located on Douquette Mound, and magne-tic North were used to initially set in an iron pipe (IP-l) which formed thenorthwestern corner of the site. Three additional iron pipes (IP-2, IP-3, andIP-4) were located from Douquette Mound and IP-l, along the eastern edge of

2

Route 13 in a straight line (1800 backsights). Based on Douquette Mound anA the

4 iron pipes, boreholes were located. Each borehole was located using triangu-lation with the set markers as well as with each other. Temporary stakes werethen set. Initial selection of borehole locations was predicated on an even

distribution over the entire site; however, cost limitations reduced the actualnumber of boreholes to five. Selection of locations therefore became critical.The site was divided into four quadrants. One borehole was approximately cen-tered in each quadrant, with the fifth hole located between the two westernquadrants. This configuration provided the maximum area exposure. Minoradjustments in locations were made based on previous soil investigations withinthe site. This spacing was also intended to provide information on locatingtrenches and seismic runs during the final exploration phase. A site plandepicting all locations is provided in Appendix F.

,o3

SECTION III

PRELIMINARY SUBSOIL EXPLORATION

1. BOREHOLE SAMPLES

Civil Engineering Research Facility (CERF) personnel and equipment assistedin the borehole sampling. A truck-mounted auger (Central Mine Equipment-ModelNo. 75) was used to drill the boreholes. A split-spoon sampler (Dimensions:Overall Length 2'8"; Inside Diameter 1-3/8"; Outside Diameter 2"; Area Ratio -

111.6%) was used to take the samples every .6-.8 meter (2-2.5 feet) down to adepth of 4.9 meters (16 feet), then every 1.5 meters (5 feet) down to a finaldepth of approximately 10 meters (32 feet). As samples were retrieved, theywere identified and placed in plastic bags. A balance and measuring tins werenot available at the site, and the downhole water content measuring device(Downhole Density Gauge Probe-Model No. 1351) was not operating. The plasticbags were used in an attempt to preserve natural water content until a labora-tory determination could be made. Field identification of samples is recordedin Section V, Table 1.

2. STANDARD PENETRATION TEST

During the sampling within boreholes, the Standard Penetration Test wasaccomplished and at each depth a sample was taken. A standard 63.5 kilogram(140 pounds) weight was dropped at a height of 76 centimeters (30 inches) toprovide an energy of 480 Joules (N-M) per blow. The weight was used to drivethe sampler to the top of each depth in consideration, then the number ofblows was recorded to drive the sampler the next 30.5 centimeters (12 inches).Two marks were made on the support rods each time to assist in determining therequired penetration. The borehole was cleaned by raising the auger andspinning the soil off. The auger was then reinserted and the sampler wasinserted in the hollow stem of the auger.

Table 2, Section V lists relative densities of the in-situ material inrelation to number of blows. Relative density is determined by the ratio of(maximum void ratio less natural void ratio) over (maximum void ratio lessminimum void ratio). Terzaghi and Peck provided a stmple correlation of rela-tive densities versus number of blows, based on numerous tests on sands.These correlations were used in developing Table 2. Additionally, the numberof blows was related to approximate values for the angle of internal friction"*", taken from a chart developed by Terzaghi and Peck. It is noted that therelationships developed by Terzaghi and Peck applied to sands. The soil atWSMR is primarily sand with varying amounts of gravel and fines. Varyingdegrees of cementation are also present, which will tend to increase thenumber of blows.

3. DOWNHOLE NUCLEAR DENSITY GAUGE

Personnel were checked out on the downhole nuclear density gauge (Model504/Serial No. 50/Standard Serial No. 107) by WSMR Radioactive Safety members.A hole approximately 10.2 centimeters (4 inches) was drilled vertically intothe ground near each borehole. A section of 6.4 cm (2.5 inches) diameterplastic pipe was then inserted into each hole to a depth of 6.7 meters (22feet). Sand was then poured around the pipe to hold the pipe in the centerof the hole. Also, the sand provided a standard medium for the nuclear par-ticles to travel through between the pipe and the soil to be measured.

4

* -. . .

S:[ -. -4 - - - - .

r. Six Standard counts (readings) for the equipment were taken. The nuclear

density gauge was then placed over the mouth of a pipe section and its probe

lowered slowly down the hole. Two counts 'readings) were taken approximately

every .61 meter (2.0 feet) until the probe could no longer be lowered (due to

crimping of plastic pipe). This procedure was repeated for each pipe section.

The following method was then used to estimate in-situ densities for the

soil. The average of the two readings at each depth was divided by the averageof the six standard counts. The result was a count ratio number. A standard

chart, provided with the equipment, was then used to relate the count rationumber to in-situ density. Results of this test are given in Section V,

Table 3.

4. TESTING PROCEDURES

A. SAMPLE PREPARATION

Fifty-four samples taken from the five borings (depths down to 9.8

meters) were analyzed. Due to the nature of this material, small amounts wereavailable for analysis at each depth; approximately 300-800 grams.

A small portion of each sample was used to obtain hygroscopic moisture

and approximate values of natural moisture content (some loss of water in bag).See Table 6, Section V. Each sample was then airdried for 24 hours and ground

by mortar and rubber pestal to separate individual particles. The samples werethen passed through a Number 10 sieve (2.0 mm). The amount retained on theNumber 10 sieve was used for a coarse-sieve analysis. The amount passing theNumber 10 sieve was divided for additional tests. Eighty grams was used for thehydrometer and fine sieve analysis. Thirty grams was used for the specificgravity test. The remainder of the minus Number 10 sieve material was used for

consistency limits (Atterberg Limits) tests.

The 80 gram sample was mixed with five grams of sodium-metahexaphosphateand approximately 300 ml of distilled water and let set for 24 hours. The

sodium-metahexaphosphate acted as a dispersing agent to further separate Indi-vidual fine particles.

B. GRAIN-SIZE DISTRIBUTION

The coarse sieve, hydrometer test, and fine sieve analysis were per-formed using standard techniques. The only problem encountered was floccula-tion during hydrometer analysis of certain samples. This could be a result ofnon-dispersion or lack of specific particle sizes. Grain-size distribution datawas obtained for each sample and is summarized in Table 4, Section V. Represent-

ative grain-size distribution curves were also prepared, to show the range of

size distributions over various depths within each borehole. These are found in

Appendix A. Table 5, Section V depicts the amounts of gravel, sand, silt, andclay-size particles over different depth ranges within each borehole.

5

C. SPECIFIC GRAVITY

The Standard test was performed on the oven-dried material less thanNumber 10 sieve-size (2.0 mm), for each sample. The specific gravity of solidswas determined by the following equation:

(Weight Dry Soil) X Gw

Gs -

(Weight Dry Soil)+(Weight Pycnometer+Water)-(Weight Pycnometer+Soil+water)

In this equation Gs is the specific gravity of solids (equal to unit weight ofsolids over unit weight of water) and Gw is the specific gravity of water.Results of this test are found in Table 6, Section V.

D. CONSISTENCY LIMITS

The minus Number 40 sieve-size (.42 mm) material was used for the con-sistency, or Atterberg Limits, tests. The technique developed by Casagrande wasused for the Liquid Limit Test, employing a standard brass cup mounted on a firmbase plate.

Water was added to each sample until a clay-like texture was achieved.A portion of the sample was then placed into the bottom of the cup, using a spat-ula, and levelled to a height of approximately 8 mm. A groove was cut into thesample with the following approximate dimensions: 11 m at top of groove and 2mm at bottom. The cup was then raised and dropped on the base plate, using acrank-handle, at a height of 1 cm. The number of blows were counted to justclose the bottom of the groove about 1.3 cm (.5 inch). Five trials were run atincreasing water contents. The number of blows versus water content was plottedand the "best-fit" straight line drawn through the points. The Liquid Limit(WL) was that water content corresponding to 25 blows on the straight line. Forthose soils with a very small amount of material available, only one WL test wasrun. The WL for the soil was then estimated using the following equation:

WL - W(N) .121

25

where N is the number of blows and W is the water content for the sample.

Three balls of soil were set aside after the initial wetting. Theseballs were then used to perform the Plastic Limit Test. Each ball was workedbetween the fingers, then rolled on a ground glass plate to form a thread. Thewater content was taken for each thread when it just crumbled at .32 cm (1/8inch). The Plastic Limit (Wp) was taken as the averzoe of the three watercontents.

The plastic range, or Plasticity Index, of each sample was found bysubtracting the Plastic Limit from the Liquid Limit. A tabulation of the con-sistency limits is found in Table 6, Section V.

6

E. SOIL CLASSIFICATION

The soil at each depth (each borehole) was classified in accordance withthe Unified Soil Classification System. This method is used by the military andappears to be the most widely accepted procedure. It takes into account grain-size distribution, uniformity and curvature coefficients, and consistencylimits. Results are found in Section V, Table 7.

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SECTION IV

DETAILED SUBSOIL EXPLORATION

1. TRENCH BULK SAMPLES

A. FIELD SAMPLING

Based on the type of soil found in each borehole, location of the bore-hole, and general terrain, trenches were located to provide bulk samples mostrepresentative of all soil types in the area. Again, due to cost limitations,only tw trenches could be excavated. This made selection of their locationsextremely critical. Final locations were selected to provide one area of rela-tively fine sandy silt with known caliche layers, and a second area of coarsergravelly sand with little cementation.

Douquette Mound, the iron pipes, and temporary boreholes were used inconjunction with triangulation to locate trenches 1 and 2. Trench i is locatedin the north central region of the area, between borings 2 and 3. Trench 2 islocated in the south central region (slightly west), between borings 1 and 5.See Appendix F.

A backhoe was used to excavate both trenches. Excavations were madedown to 1.2-1.5 meters (4-5 feet), 2.6-2.9 meters (8.5-9.5 feet), and 3.7-4.0meters (12-13 feet). Further depths were prohibited due to backhoe limitations.At each depth, bulk samples of approximately 91 kilograms (200 pounds) werehand-excavated and placed in containers. Small samples from each container weretaken for natural water content determinations. Trench I had a loose sandy siltdown to 1.2 meters (4 feet); then caliche down to 4.0 meters (13 feet). Below4.0 meters (13 feet), the caliche appeared to continue. Trench 2 had a loosesandy silt down to .6 meters (2 feet); then caliche down to 2.4 meters (8 feet);then lightly cemented gravelly sand (with rocks up to 10 cm (4 inches) diameterdown to 3.0 meters (10 feet); then loose, gravelly sand down to 4.0 meters (13feet). Below 4.0 meters (13 feet), the loose, gravelly sand appeared tocontinue.

B. TESTING PROCEDURES

Classification tests were accomplished on the six samples (2 trencheswith 3 depths each) in a procedure similar to Section 111-4. These testsincluded the coarse-sieve analysis, hydrometer and fine-sieve analysis, specificgravity test, consistency limits, natural moisture content, and hygroscopicmoisture content. Results can be found in Section V, Tables 4-7.

2. SEISMIC SURVEY

This subject is covered separately in Section IX, Subsurface Seismic

Investigations.

3. STANDARD PROCTOR TEST

The standard proctor test was performed on all trench samples to providedata on maximum dry density versus optimum moisture contents. Material passing

4 the Number 4 sieve (4.76 mm) was used. Equipment included a 10.2 cm (4 inch)

8o s,

- ""... . - _ . ,.." " ". . , " - _ -

mold with an inner volume of .0009 m3 (.033 feet 3) and a 2.5 kilogram (5.5pounds) hammer (weight). Each sample was compacted in 3 layers at 25 blows perlayer, with a 30.5 cm (12 inches) drop of the weight. Each sample was compactedat increasing water contents until the total weight dropped off. Values of drydensity versus water content were plotted and a smooth curve drawn through thepoints. The peak of the curve was taken as the maximum dry density and optimummoisture content. Results of these tests are found in Section V, Table 8.

4. UNCONFINED COMPRESSION TEST

Samples from each trench depth (except Trench 2, Depths 2.6-2.9 meters and3.7-4.0 meters) were compacted into cylinders 7.12 cm (2.802 inches) high andwith a 3.56 cm (1.402 inches) diameter. Soil from Trench 2, Depths 2.6-2.9meters and 3.7-4.0 meters could not be molded into cylinders due to the highsand content. The cylinders were compacted in 5 layers at 13 blows per layer.A .33 Kilogram (.72 pounds) hammer was used at a drop height of 38.1 cm (15 inches).

Cylinders were made at approximately 2 percent less than optimum moisturecontent, optimum moisture content, and optimum moisture content plus 2 percent.Additionally, a separate cylinder at each moisture content was prepared thenallowed to dry for 72 hours. The intent was to see how well these cylinders setup when allowed to dry from various moisture contents. Increases in peakfailure stress under these conditions are discussed in Section VIII, Effectsof Caliche on Static Strength Properties.

Each cylinder was tested on a standard compression machine (Wykeham FarranceEng. LTD, England, Capacity 10 Tons/WTE 42 Speed Gear Box) with zero confiningpressure. A vertical force was applied at a (gear speed) rate of .65 mm perminute until failure was indicated by a drop in axial force accompanied withhigh strain changes. Typical shear failures could be obtained in all cylin-ders except those which had been allowed to dry. These cylinders achievedmuch higher peak stresses at low strains, then tended to rupture violentlyonce peak stress was reached. Tabulated results of this test are found inSection V, Table 9.

5. TRIAXIAL COMPRESSION TEST

Samples from each trench were compacted in cylinders similar to those usedin the unconfined compression test. All samples (Unconfined and Triaxial) werecompacted at the same time to achieve similar water contents (Wopt - 2%; Wopt;Wopt + 2%), then sealed with aluminum foil and hot wax to preserve moistureuntil testing. These samples were then tested on the same Wykeham Farrance Eng.LTD compression equipment. A plastic cell containing water surrounded the soilsample during testing. Pressurizing the water (by expanding a rubber membranein an outer cell) created an all-around confining pressure on the sample. Threedifferent confining pressures were used (51.7 KN/m2 (7.5psi); 86.2 KN/m2

(12.5 psi); 120.7 KN/m2 (17.5psi)). A vertical force (in addition to the con-fining pressure) was then applied at a (gear speed) rate of .65 mm per minuteuntil failure occurred.

Additional samples from each trench were tested in triaxial compression,using air-dried soil. The method used to make cylinder samples was as follows:Attached rubber membrane to base plate (over porous stone) with 2 0-rings;assembled 3-piece metal collar around rubber membrane and stretched top of

9

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7.. ,' V

membrane over top of collar; added soil in 5 layers and rodded each layer 30times; leveled top of soil and added a top porous stone; added plastic headover porous stone; unfolded top of membrane over porous stone and plastic headand attached 2 O-rings (above collar); hooked up vacuum to base plate andclosed all valves; turned vacuum on for a few seconds at 34.5 KN/m2 (5psi)then closed valve on base plate before turning vacuum off; unhooked vacuumand removed collar; released the vacuum pressure inside the membrane, afterthe confining pressure had been applied. These samples were then tested by astep application of 3 different confining pressures. An all-around confiningpressure of 51.7 KN/m2 (7.5psi) was applied, then the vertical stress wasincreased until failure was imminent (small stress changes with large strainchanges). The compression machine was turned off and the confining pressureincreased to 86.2 KN/m2 (12.5psi). The compression machine was then turned onand the axial stress increased until failure was imminent, then the stress wasremoved. This was repeated one more time at a confining pressure of 120.7KN/m2 (17.5psi); however, the sample was allowed to fail for this final step.

Results of all triaxial tests are found in Table 10, Section V, and includethe peak deviator stress at failure versus percent strain, the failure modulus"Ef", and the initial tangent modulus "EIT".

%1

101

SECTION V

TESTING RESULTS

Results of each classification and strength test are presented in tabulated* ,form in this section. Any accompanying graphs can be found in separate

appendices.

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TABLE 1

FIELD IDENTIFICATION OF SOIL

Borehole Depth DescriptionMeters (Feet)

B-i .31-.61(1-2) Light brown; sandy silt; less than 1 percentgravel; crumbles easily in fingers.

.1-1.4(3.5-4.5) Light brown; silty sand with minor cementa-tion; 3-5 percent gravel; some difficulty inbreaking clumps with fingers.

1.8-2.1(6-7) Light brown; fine sand with some silt; lessthan 1 percent gravel but larger size (up to1 inch); crumbles easily in fingers.

2.6-2.9(8.5-9.5) Dark brown; gravelly sand with some fines;few large cobbles up to 3 inches; coursermaterial.

3.4-3.7(11-12) Brownish gray; sandy gravel with sizes up to

2 inches.

4.1-4.4(13.5-14.5) Similar to 3.4-3.7 meters depth.

4.9-5.2(16-17) Similar to 3.4-3.7 meters depth.


6.4-6.7(21-22) Dark brown; course sand with fines; clumpsI , are disc-shaped; heavy cementation; clumps

cannot be broken with fingers.

7.9-8.2(26-27) Dark brown; fine silty sand with some gravel;"." clumps are disc-shaped; moderate cementation;; clumps break in fingers with some difficulty.

____9.4-9.8(31-32) Similar to 7.9-8.2 meters depth.

B-2 .31-.61(1-2) Light tan to grayish brown; fine sandy silt.

1.1-1.4(3.5-4.5) Similar to .31-.61 meter depth.

1.8-2.1(6-7) Similar to .31-.61 meter depth but with light

cementation.

2.6-2.9(8.5-9.5) Slightly darker tan; sandy silt; clumps aredisc-shaped; clumps break easily in fingers.

3.4-3.7(11-12) Similar to 1.8-2.1 meters depth; some clumps

_ _,_ _ _which break easily in fingers.

12

TABLE 1 (continued)

Borehole Depth Description

Meters (Feet)

B-2 4.1-4.4(13.5-14.5) Similar to 3.4-3.7 meters depth but has(cont'd) disc-shaped clumps which break easily in

hand.

4.9-5.2(16-17) Light tan; sandy silt with some gravel; mod-erate cememtation; clumps break in fingerswith some difficulty.


7.6-7.9(25-26) Dark brown; fine silty sand; clumps breakeasily in fingers.

7.9-8.2(26-27) Dark brown with light tan mottled tone;fine sand with some gravel and silt; heavycementation; clumps are disc-shaped; clumpscannot be broken with fingers.


B-3 .31-.61(1-2) Light brown; sandy silt with less than 1P percent gravel.

1.1-1.4(3.5-4.5) Light .tan; fine silty sand with less than 1percent gravel; some pieces up to 2 inchessize.


2.6-2.9(8.5-9.5) Similar to 1.1-1.4 meters depth but withlight cementation.

3.4-3.7(11-12) Dark tan; silty sand; moderate cementation;clumps break in fingers with some diffi-culty.


4.6-4.9(15-16) Light brown; loose layer of silty sand.




7.9-8.2(26-27) Light brown; silty sand with some gravel;material courser and has some granitepieces; some gravel up to 2 inches size.

9.4-9.8(31-32) Similar to 7.9-8.2 meters depth but has

disc-shaped clumps which break in fingers_ _-_with some difficulty; moderate cementation.

TABLE 1 (continued)

Borehole Depth Description'_ _ Meters (Feet)

B-4 .31-.61(1-2) Light brown; sandy silt.

1.1-1.4(3.5-4.5) Reddish brown; silty sand with some gravel;light cementation; clumps are disc-shaped;clumps break easily in fingers.

1.8-2.1(6-7) Tan; course sand with some fines; 3-5 per-

-cent gravel; some cobbles up to 2 inches.

2.6-2.9(8.5-9.5) Similar to 1.8-2.1 meters depth butslightly higher gravel content.



4.9-5.2(16-17) Dark reddish brown; silty sand with somegravel; moderate cementation; clumps breakin fingers with some difficulty.

6.4-6.7(21-22) Light brown; silty sand with some gravel;moderate cementation; clumps are disc-shaped; clumps break in fingers with some

,_ _ _ difficulty.


9.4-9.8(31-32) Reddish brown to light tan mottled tone;

silty sand; heavy cementation; clumps aredisc-shaped; clumps cannot be broken infingers.

B-5 .31-.61(1-2) Light brown; sandy silt; less than I per-cent gravel.

1.1-1.4(3.5-4.5) Light tan to white; fine powder silt toclay size; light cementation.

1.8-2.1(6-7) Similar to .31-.61 meter depth but withlight cementation; clumps break easily infingers.

2.6-2.9(8.5-9.5) Light brown; slightly courser sand with siltand some gravel up to 2 inches size; moder-ate cementation; clumps break in fingerswith some difficulty.

r3.4-3.7(11-12) Similar to 2.6-2.9 meters depth.

J A " - .

TABLE 1 (continued)

Borehole Depth DescriptionMeters (Feet) ________________ ______

B-5 4.1-4.4(13.5-14.5) Similar to 1.1-1.4 meters depth but with(cont 'd) ___________ moderate cementation.



7.9-8.2(26-27) Reddish brown; silty sand with some gravelup to 3 inches size; heavy cementation;clumps are disc-shaped; clumps cannot be

__________________ broken with fingers.

________ 9.4-9.8(31-32) Similar to 2.6-2.9 meters depth.

TABLE 2

STANDARD PENETRATION TEST INTERPRETATIONS

B orehole Depth Blows/Foot Relative Condition Angle of InenalMeters (N) Density Friction *(Degree~

_____ (Feet) ______Dr (percent) _______ _________I

B-i .31-.61(1-2) 15 40-60 Med. Dense 31.51.1-1.4(3.5-4.5) 54 80-100 Very Dense 42.01.8-2.1(6-7) 25 40-60 Med. Dense 34.52.6-2.9(8.5-9.5) 31 60-80 Dense 36.33.4-3.7(11-12) 66 80-100 Very Dense 43.74.1-4.4(13.5-14.5) 46 60-80 Dense 40.44.9-5.2(16-17) 52 80-100 Very Dense 41.65.6-5.9(18.5-19.5) 29 40-60 lied. Dense 35.86.4-6.7(21-22) 53 80-100 Very Dense 41.87.9-8.2(26-27) 29 40-60 Med. Dense 35.8

____9.4-9.8(31-32) 48 60-80 Dense 40.9

B-2 .31-.61(1-2) 23 40-60 Med. Dense 33.91.1-1.4(3.5-4.5) 39 60-80 Dense 38.61.8-2.1(6-7) 47 60-80 Dense 40.6

*2.6-2.9(8.5-9.5) 33 60-80 Dense 36.63.4-3.7(11-12) 43 60-80 Dense 39.54.1-4.4(13.5-14.5) 87 80-100 Very Dense 44.04.9-5.2(16-17) 91 80-100 Very Dense 44.06.4-6.7(21-22) 51 8-100 Very Dense 41.27.9-8.2(26-27) 70 80-100 Very Dense 44.0

-'____ .4-9.8(31-32) 32 60-80 Dense 36.5

B3 .31-.61(1-2) 12 40-60 Med. Dense 30.51.1-1.4(3.5-4.5) 27 40-60 Med. Dense 35.21.8-2.1(6-7) 31 60-80 Dense 36.32.6-2.9(8.5-9.5) 63 80-100 Very Dense 43.13.4-3.7(11-12) 9i. 80-100 Very Dense 44.04.1-4.4(13.5-14.5) 76 80-100 Very Dense 44.04.9-5.2(16-17) 85 80-100 Very Dense 44.06.4-6.7(21-22) 45 60-80 Dense 40.17.9-8.2(26-27) 52 80-100 Very Dense 41.6

_____9.4-9.8(31-32) 53 80-100 Very Dense 41.8

B-4 .31-.61(1-2) 37 60-80 Dense 38.1

1.1-1.4(3.5-4.5) 44 60-80 Dense 39.91.8-2.1(6-7) 49 60-80 Dense 41.02.6-2.9(8.5-9.5) 24 40-60 Med. Dense 34.13.4-3.7(11-12) 28 40-60 Med. Dense 35.54.1-4.4(13.5-14.5) 34 60-80 Dense 36.84.9-5.2(16-17) 42 60-80 Dense 39.26.4-6.7(21-22) 42 60-80 Dense 39.27.9-8.2(26-27) 27 40-60 Med. Dense 35.21____9.4-9.8(31-32) 11il1 80-100 1Very Dense 144.0

16

TABLE 2 (continued)

Borehole Depth Blows/Feet Relative Condition Angle of InternalMeters (N) Density Friction(Feet) Dr (percent) ( ) Degrees

B-5 .31-.61(1-2) 18 40-60 Med. Dense 32.51.1-1.4(3.5-4.5) 49 60-80 Dense 41.01.8-2.1(6-7) 50 60-80 Dense 41.12.6-2.9(8.5-9.5) 81 80-100 Very Dense 44.03.4-3.7(11-12) 40 60-80 Dense 38.84.1-4.4(13.5-14.5) 74 80-100 Very Dense 44.04.9-5.2(16-17) 66 80-100 Very Dense 43.76.4-6.7(21-22) 35 60-80 Dense 37.27.9-8.2(26-27) 66 80-100 Very Dense 43.79.4-9.8(31-32) 48 60-80 Dense 40.9

I.7

.°°7

TABLE 3IN-SITU DENSITIES

Depth In-Situ Density

Borehole Meters (Feet) Kg/m 3 (pcf)

B-1 .31 (1.0) 1,617.9 (101.0).91 (3.0) 1,734.8 (108.3)

1.52 (5.0) 1,758.8 (109.8)2.13 (7.0) 1,798.9 (112.3)2.74 (9.0) 1,746.0 (109.0)3.35 (11.0) 1,830.q (114.3)

3.96 (13.0) 1,734.8 (108.3)4.57 (15.0) 1,802.1 (112.5)

B-2 .31 (1.0) 1,566.7 (97.8).91 (3.0) 1,689.9 (105.5)

1.52 (5.0) 1,665.9 (104.0)

2.13 (7.0) 1,638.7 (102.3)2.74 (9.0) 1,826.1 (114.0)3.35 (11.0) 1,689.9 (105.5)3.96 (13.0) 1,786.1 (111.5)4.27 (14.0) 1,814.9 (113.3)

B-3 .31 (1.0) 1,874.2 (117.0).91 (3.0) 1,617.9 (101.0)

1.52 (5.0) 1,726.8 (107.8)2.13 (7.0) 1,830.9 (14.3)2.74 (9.0) 1,738.0 (108.5)3.35 (11.0) 1,770.0 (110.5)

B-4 .31 (1.0) 1,638.7 (102.3).91 (3.0) 1,630.7 (101.8)

1.52 (5.0) 1,702.8 (106.3)2.13 (7.0) 1,722.0 (107.5)2.74 (9.0) 1,850.1 (115.5)3.35 (11.0) 1,806.9 (112.8)

3.96 (13.0) 1,887.0 (117.8)4.57 (15.0) 1,814.9 (113.3)

S 5.18 (17.0) 1,890.2 (118.0)

5.49 (18.0) 1,879.0 (117.3)

. ...

D.

TABLE 3 (continued)

B-5 .31 (1.0) 1,606.7 (100.3)

.91 (3.0) 1,590.6 (99.3)

1.52 (5.0) 1,670.7 (104.3)

2.13 (7.0) 1,734.8 (108.3)2.74 (9.0) 1,770.0 (110.5)3.35 (11.0) 1,673.9 (104.5)3.96 (13.0) 1,6Q4. 8 (105.8)4.57 (15.0) 1,654.7 (103.3)5.18 (17.0) 1,649.9 (103.0)

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33

SECTION VI

DISCUSSION OF RESULTS

Initial field investigation of soil, as depicted in Table 1, indicatedthat the entire area of White Sands Missile Range in this survey consists pri-marily of sandy soil with varying degrees of fines. This type soil is typicalin alluvial plains. Further laboratory testing and classification of the soilsamples agreed with these initial findings. Four specific categories of soilare evident throughout the area. These are clayey sand (SC), silty sand (SM),silty sand to clayey sand (SM-SC), and low plasticity clay (CL). UsingMILLRACE GZ-3 as the center of the area, the southern half appears to consistof a top layer of clayey sand ranging from 1-3 meters (3-10 feet) thick, withthe thicker layers lying west of GZ-3. The clayey sand is underlain by a layerof silty sand ranging from 1.5-4.6 meters (5-15 feet) thick. This isfollowed by a layer of clay 2.1-2.7 meters (7-9 feet) thick, underlain byclayey sand. The northern half of the site consists of similar layers;however, the clay layer appears to be closer to the surface. In the westernsection of the North half, clay is seen about 4.6 meters (15 feet) below theground surface. East of Douquette Mound clay is at the ground surface andreaches thicknesses of 7 meters (23 feet).

Particle size distribution varies over wide areas, as well as depths. Thefiner soils are located much deeper in the southern half of the site, whilethe northern half has the finer soil at relatively shallow depths. It is ofinterest to note that a comparison of Tables 5 and 7 shows a very small per-centage of clay-size particles in the borehole depths classified as CL. Thisphenomena can best be explained by the results of the hydrometer test. Theseparticular soils (CL) contained large amounts of cementing agents in eitherpowder or clump form which created a non-dispersion of particles during thehydrometer test. This was evidenced by visible flocculation within thesolutions. As a result, Table 5 clearly shows that these soils have thehighest content of silt-size particles. If dispersion had been effective, thesilt-size "clumps" would have separated, causing an increase in the clay-sizeparticles.

All of the soils investigated are well graded based on their coefficientof curvature and uniformity. Additionally, natural and hygroscopic moisturecontents tend to be very low and nearly equivalent. Liquid limits and plasti-city indexes are low, with a slightly higher plastic range in the clay areas.Specific gravities varied from 2.61 to 2.81. The higher specific gravitiesappeared to correlate with areas of obvious cementation, in most cases. Thisis expected since calcite has a specific gravity of about 2.72.

Standard penetration test results indicated the in-s , soil to be denseto very dense over the entire site, to the full 10 meter (32 feet) depth. Afew areas of medium density and pockets of loose gravelly sand were foundsporadically throughout the site. This tends to corroborate the existence ofcaliche in this area. N-values were very high for certain layers (greaterthan 50) and reached 90-111 in some cases. Caliche will be looked at furtherin Section VIII of this report. Specific in-situ densities taken with thedownhole nuclear density gauge ranged from 1567-1890 Kg/m3 (98-118 pcf), with

34

.9

the higher densities at lower depths as would be expected. Maximum dry den-sities, as determined from the Standard Proctor Test, ranged from 1658-2010Kg/m3 (104-125 pcf) at depths down to 4 meters (15 feet). The higher valueswere found in the soils containing larger amounts of clay-size particles orgravelly sand. Soils with higher amounts of silt-size particles to fine sandtended to have lower maximum dry densities.

Unconfined compression tests were run solely on soils with high silt and

clay-size percentages due to mold limitations, while triaxial tests includedsoils with higher gravel and coarse sand contents. Young's Modulus at failuretends to be higher at shallower depths and lower water contents (about 2-3%below optimum). Additionally, the modulus is higher in the soils with highpercentages of clay-size particles. Peak failure stresses for both confinedand unconfined conditions also follow this pattern, while strains tend toincrease with increasing water content (above optimum). The highest failurestresses were found in the soils containing larger amounts of fines. Forthese soils, peak failure stresses ranged from 400-700 KN/m2 (59-100 psi) if ahigh clay-size content was evident. If a high silt content was evident, peakfailure stresses ranged from 500-675 KN/m 2 (73-98 psi). Lower failure stressvalues were evidenced at higher water contents for both cases. See Tables 9and 10.

Two additional tests were accomplished. First, specimens were compactedat various water contents matching those used in the unconfined compression

test. These cylinders were then allowed to air dry for 72 hours at which timethey reached hygroscopic moisture contents. As time passed, they becamestronger as evidenced by feel and sight. The cylinders were then tested inunconfined compression. Failure stress increases, from this wetting/dryingcondition, ranged from 400-5300 percent. Peak failure stresses tended toincrease more with increasing initial water content, increasing depth, and ahigher silt fraction (vice clay).

The second additional test performed was triaxial compression on samplescompacted from air-dry soil. In this case, the water contents were alsohygroscopic, however particle cementation was not allowed. Peak failurestresses decreased significantly from values found in the other (wet sample)triaxial tests, and tended to be highest in the coarser soils (up to 485KN/m2 ).

35

ki!

-7

SECTION VII

CONCLUSIONS

The previous field and laboratory test results lead to the followingconclusions:

(1) The site at WSMR, characterized by this project, consists primarilyof sandy soil with traces of gravel throughout the region. Heavier gravelcontents are found in the southern region. The sand has varying degrees offines and has been deposited in alternating layers of SM, SM-SC, and SC, withsome thick layers of low plasticity clay.

(2) The in-situ soil is dense to very dense over most of this region andshows strong evidence of caliche.

(3) Peak failure stresses of soil samples tested for this site vary overa large range, up to 700 KN/m2 (7.2 tons per square foot) in a vet condition.The actual in-situ strength is most likely higher, since the natural moisturecontents tend to be near the hygroscopic moisture contents and the in-situdensities are high. The tests indicated that failure stresses increasedsignificantly for compacted samples which were first wet, then allowed to dry.Past geological conditions indicate that actual wetting/drying periods didoccur.

(4) The items evaluated in regard to analysis of weapon systems effectsIncluded material index properties, grain-size distribution, specificgravities, and deformation versus strength properties. Results are found inTables 1-10 and Appendices A-F. Additional information on caliche andseismic refraction is available in Sections VIII and IX.

(5) This report primarily evaluated static properties of the subsoil.Detailed testing of dynamic properties should also be conducted to providebetter correlations with the dynamic effects of weapon blasts. Some recom-mended test are seismic surveys which determine both shear and compressivewaves, the dynamic odometer which uses impulse loads, and the cylindrical in-situ test (Reference 1) which uses high explosive shock impulses in the field.

36

2 ..

SECTION VTII

EFFECTS OF CALICHE ON STATIC STRENGTH PROPERTIES

1. INTRODUCTION

Numerous tests and reports by the Air Force Weapons Laboratory, as well asthe Civil Engineering Research Facility, have indicated the presence ofcemented soils known as "caliche" within the boundaries of White Sands MissileRange (WSMR), New Mexico. Due to the nature of this range (test site), eachreport has attempted to characterize the type of cementation and its possibleeffects on soil properties. None of the reports located, however, indicatedany actual laboratory tests having been performed.

The purpose of this section of the project is to delineate the nature ofcaliche which may be expected in this region and to correlate this withvarious soil properties and strength parameters. Prior to discussing actualtests performed, a look at the current state-of-the-art is in order.

2. STATE-OF-THE-ART

Much research on caliche has been accomplished in South and SouthwesternAfrica by the National Institute for Road Research. This research has beendocumented in many articles through the years by F. Netterberg, who has gainedexpertise in this field. Many names are used to describe "cemented soil"throughout the world, to include: caliche, surface limestone, hardpan,kankar, jigilin, and duracrust. F. Netterberg uses the name "calcrete," whichwas coined by Lamplugh (1902) and originates from the two Latin words, "calx,"meaning lime, and "crescere," meaning grow (or lime grown together). Thisappears appropriate, since ca:crete is essentially created from lime substances(e.g., calcium) which grow within the soil itself by the formation of crystals.

The main chemical composition of calcrete is calcium and silicate withsmaller amounts of magnesim, alumina, and iron in the forms CaO, SiO 2 , MgO,A1203, and Fe202. Calcium is generally found as a carbonate (or calcite),CaC03, while magnesium is always present in the form of dolomite. These twocompounds are generally found to be the cementing agents in calcrete, withcalcium carbonate being the primary agent. Magnesium is found in much smalleramounts, primarily due to wetter initial periods, and tends to increase withdistance from the rock source. Calcium carbonate is generally present asfine-grained material adhering to detrital quartz grains and traversed bysilica and course calcite veins.

Calcrete is formed in stages, where hardness increases over each stage.Initially, carbonate is precipitated from soil or ground water acting over(or from) a calcium and magnesium-producing source (certain rocks releasethese chemicals upon weathering). Calcrete is, therefore, a pedogenic materialwhich is formed by near-surface cementation or replacement of a host soilduring the precipitation and evaporation process. The stages of formation arerepresented in Table 11.

37

?... . . . .... .

-w

Table 11

CALCRETE FORMATION

(Initial) Sand or Gravel with Silt or Clay (Initial) Heavy Clay-size

with carbonate-coated grains concentrations

(Stage 1) Calcified Sand or Gravel (Stage 1) Powder Calcrete

(Stage 2) Nodular Calcrete

(Stage 3) Honeycomb Calcrete

(Stage 4) Hardpan Calcrete

(Stage 5) Boulder Calcrete

Powder calcrete is a fine, loose, powder consisting of calcium carbonatewith few visible soil particles and little or no nodular development. It hasa large silt or clay-size faction in it. Calcified sand, or gravel, isgenerally loose material weakly cemented by calcium carbonate and has a highersand or gravel content. Nodular calcrete is discreet, usually intact, verysoft to very hard concentrations of carbonate-cemented soil, with the maximumdiameter of nodules less than 6.35 cm (2.5 inches). Honeycomb ralcrete iscontinuously honeycombed with voids up to 2.54 cm (1 inch) diameter filledwith basic soil. Hardpan calcrete is a firm to very hard sheetlike layerunderlain by looser material, where the layer is generally less than 45.7 cm

'? (18 inches) thick. The material underneath is not cemented, most likely dueto the hardpan layer becoming impermeable (stops further leaching) or adecrease in rainfall which would decrease the leaching depth. Hardpan can

',. occur as sheet, tufaceous (porous), shattered, bedded (layered), or conglom-eratic (cemented river gravels). Boulder calcrete is weathered hardpan

" (forms boulder-like pieces).

The formation of calcrete is relatively simple. Calcium carbonate isreleased fixm some source, such as river water, alluvial run-off, orweathering of underlying bedrock. The calcium carbonate, which is in solutionin water, is then leached down to lower layers of the subsoil due to increasedrainfall, increased permeability of top soil layers, or a decrease in tem-perature (causes decrease in evaporation). As the calcite settles out ofsolution, it adheres to and grows on surrounding soil particles. Evaporationof soil or ground water increases this growth process. Greater thicknesses ofcalcrete are found in semiarid regions where annual rainfall is less than 550mm (21.7 inches) and there is a fluctuating but steadily dropping water table.The distribution and thickness of calcrete are dependent on the five factorsresponsible for soil formation. These are climate, topography, parentmaterial, biological factors, and time. Geology is also important and is a

38

•. - . ~ - - ~ - - . - . . .- - - - . -- . o - . , o--- • ,-'*- --

subfactor of parent material. As previously stated, the primary climatic con-dition necessary is a mean annual rainfall less than 550 mm. If higher temper-atures prevail, then a higher amount of rainfall is required to form calcrete,up to 625 mm (24.6 inches). The depth of calcrete formation increases withincreased rainfall, due to increased leaching. Topographically, calcrete isnormally found in flatter regions or in depressions, where moisture canaccumulate, weather underlying soil, release calcium and magnesium, and evap-orate in-situ. This is particularly true in alluvial plains. Drainage bedscan also be excellent locations for calcrete, providing all other conditionsare met. As far as parent material is a concern, calcrete is most likely toform over calcareous rocks, such as limestone, dolomite, calcareous shales,mudstones, and basalt which release calcium and magnesium on weathering. Itmay also be found over granite or sandstone if drainage conditions arefavorable. For a given climate, calcrete formation is slower in a less per-meable soil. Essentially, biological factors concern vegetation. Calcretestend to be associated with the presence of bush and grass cover. Specifically,certain types of calciphilic plants are evident in calcrete areas. Some ofthese are gabbabos, saliebos, and vaalbos. Plants of the Acacia reficiensgenus (woody, leguminous plants of warm regions with pinnate leaves or leavesreduced to phyllodes-branches resemble foliage leaves and white or yellowflower clusters) can also be found in calcrete regions. Although not

-. calciphilous, acacia plants indicate the presence of shallow water which canindicate calcrete in a semiarid region. The last factor for calcrete for-mation is time. Time tends to increase the developmental stage and hardnessof calcrete formed.

Based on the factors which form calcrete, there are several ways availableto detect calcrete formations. Some of these are seismic surveys, aerial pho-tography analysis, infrared imagery, and-probing. Seismic analysis entailsthe measurement of seismic wave velocities in the subsoil and is covered indetail in Section IX of this report. Essentially, the various forms ofcalcrete have seismic velocities as listed in Table 12.

Table 12

SEISMIC VELOCITIES OF SUBSURFACE CALCRETE

VelocityType Cal crete m/sec (feet/sec)

Calcified Sand 450-1200 (1476-3937)

Powder Calcrete 400-1000 (1312-3280)

Nodular Calcrete 600-900 (1968-295?)

Honeycomb Calcrete 900-1200 (2952-3937)

Hardpan Calcrete 1200-4500 (3937-1A,763)

Boulder Calcrete Erratic

.9

'. .. ... . . .. . . .. . .

Items, such as topography, drainage, vegetation, parent material, andbasic geology, can be inferred from aerial photo interpretation and infraredimagery. Probing involves the hammering of a metal probe (2-inch diameterpipe with top 10 inches solid and bottom 12 inches hollow with rod or probe atbottom that is 3/3 inch in diameter and 84 inches long) into the ground untilrefusal or concerned depth is reached. Penetration resistance is taken as anindicator of the relative strength of the calcrete and is related to type ofcalcrete as seen in Table 13.

Table 13

INTERPRETATION OF PENETRATION RESISTANCE

PenetrationResistance Color of Soil Calcrete Type

Low White (sandy) Calcified SandLow to Fair White Powder CalcreteFair to High White or Pale Pink Tufaceous HardpanHigh White or Pale Pink Loose, Hard Nodular

Calcrete or StiffHardpan

Refusal White or Pale Pink Hard to Very HardBoulder Calcrete orSheet Hardpan

Other properties of calcrete include: crushing strength, plasticityindex, particle-size distribution and grading. Crushing strength tends toincrease with time and fineness of particles. In the field, strength is takenas a function of Mohs' Hardness Scale. Mohs' hardness values typically foundin calcrete are powder and calcified sand (0-1), nodular calcrete (1-5),honeycomb calcrete (2-5.5), hardpan (1.5-6), and boulder calcrete (3-5).Mohs' scale for hardness is relative as depicted in Table 14.

Table 14

MOHS' HARDNESS SCALE

Type Mineral Relative Hardness Value

Talc (Magnesium Silicate) 1Gypsum (Calcium Sulphate) 2Calcite (Calcium Carbonate) 3Fluorite (Calcium Fluoride) 4Apatite (Calcium Phosphate) 5Orthoclase (Potassic Feldspar) 6Quartz 8Fused Alumina 12Diamond 15

40

'V

Plasticity index may be a poor indicator of calcrete quality due to theunreliability of obtaining the index, and a high plasticity index may be foundwhile pure calcium carbonate is non-plastic (with high liquid limit about 30percent). Even so, the plasticity index is often used as an indicator whereit tends to be higher if the calcrete was formed in clays rather than sandsand generally increases with depth. The plasticity index tends to fall in thefollowing ranges: calcified sand (0-150), powder (3-15), nodular (0-20),honeycomb (0-20), hardpan (0-3), and boulder (0-3). Reddish to brownish colormay indicate a lower plasticity index in calcrete as well as a courser factionin particle-size. Grey to white colors would indicate the opposite. Ingeneral, calcretes tend to be poorly graded with a high silt or clay-sizefaction. Calcified sand and powder calcrete tend to have in-situ densitiesfrom a loose condition to medium dense. Nodular calcrete is loose, whilehoneycomb, hardpan, and boulder calcrete are dense to very dense.

Another observation about calcrete is that it tends to cement or"self-stabilize" when subjected to alternate wetting and drying periods.Additionally, flocculation is frequently encountered during hydrometeranalysis. Flocculation can be prevented by the addition of 20 ml of a 36gm/liter solution of tetra sodium pyrophosphate, as a dispersing agent.


A. LIBRARY SEARCH

This portion, entitled "Library Search," is included to explain whycaliche, or calcrete, was suspected in the 2.59 kilometers squared (1 squaremile) area of concern at WSMR. Section II.1 of this report stated that thearea was primarily an alluvial basin with possibilities of underlying igneous

. rock, such as granite or basalt. The region is also semiarid which has pastperiods of alternating wet/dry seasons and currently has a very low annualrainfall. The actual water table is very deep (about 60-90 meters belowground). Average particle sizes are silt-size to sand. Topography is rela-

tively flat with the existence of old lake playas and erosion channels.Vegetation is primarily bush and grass (cactus and yucca trees). Additionally,the field standard penetration test indicated very high N-values (Medium tovery dense), which was also indicated by the downhole nuclear density gaugeresults. Actual particle-size distribution found through laboratory testingshowed areas with high silt or clay-size content along with a high percentageof sand. Liquid limits and plasticity indexes ranged from 15-36 and 0-18.The color of samples taken from boreholes and trenches ranged from greyishwhite to reddish brown.

a.

All of the previous findings are indicators of the presence of caliche,as evidenced by current state-of-the-art research. Several reports by differentagencies have also indicated the presence of caliche in the form of calciumsulphates (gypsum) or calcium carbonates; however, detailed analysis was notperformed in the region of concern at WSMR. One report, "HAVE HOST Cylindrical

a.- In-Situ (CIST) Data Analysis and Material Model Report," specifically foundy. that caliche tended to form more in the regions of sands with fines than in

clean sands.

Based on this evidence and the fact that the two trenches representeda,.

a. 41

7,',

F.

three different soil types (High Clay-Fraction, High Silt-Fraction, RelativelyClean Gravelly Sand), it was decided to test for actual content of calcium andmagnesium, type of chemical formation (carbonate, sulphate, or silicate), andvarious strength properties.

B. PREPARATION OF SAMPLES

Literature on soil chemistry indicated numerous tests for carbonateconcentrations, most of which dealt with a very slow process of titration. Inlieu of this, it was decided to perform the much quicker Atomic Absorbance(AA) test. Preparation of samples was fairly standard in all the varioustests. First, about 9 kg (20 pounds) of soil from each trench depth (two

trenches at three depths each) was air-dried, then riffle-split three times toobtain approximately 1 kg (2.2 pounds) of sample. This material was ground ina morter and rubber pestal , then passed through a number 10 sieve (2.0 mm).The material passing the number 10 sieve was quartered four times to obtain arepresentative sample of about 200 grams. This material was then passedthrough a number 40 sieve (.42 mm).

The next step was to prepare a reagent which would release the Ca++and Mg++ elements from the soil samples. The best reagent appeared to bediluted hydrochloric acid. "A Textbook of Soil Chemical Analysis" recommendedusing a 4-molar hydrochloric acid (4M HCL) solution. The solution was,therefore, made by adding 140 ml of concentrated HCL to 260 ml of distilledwater to form 400 ml of solution. Four hundred milliliters were deemed ade-quate (vice 1 liter) for the number of samples to be tested (need about 30 mlof solution per sample). The amount of soil to be used in the test variesaccording to expected CaCO 3 concentration in the minus number 40 material.Table 15 shows the amounts to be used.

Table 15

AMOUNT OF SOIL USED IN SAMPLES

Amount of Soil Used (grams) Percent CACO3

20 0-510 5-105 10-202 20-501 50

Five grams of soil were used, since a concentration of 10-20 percentCaCO 3 was expected in most samples. Thirty milliliters of 4M HCL were placedin each of 24 plastic flasks. Five grams of soil from each depth were addedto a flask (four samples taken from each of six depths). The flasks wereagitated for approximately 15 minutes in a mechanical shaker. The solutionwas then filtered through coarse filter paper into test tubes. The result wasa clear, yellow liquid. This yielded soil concentrations of about 167 gm/liter.

During the actual AA test, this dilution ratio was found to be outside4.4

~42

p. .

the range of standards, therefore, each flask was further diluted. Anapproximation of the dilution factor was made by testing the standards first.The final dilution factors used were 1:400 (1 ml solution to 399 ml distilledwater) for the calcium readings and 1:10 for the magnesium readings. It wasnoted that the actual concentrations would then be determined by multiplyingthe dilution factor (400 or 10) times the concentration found in the AA test.

C. PREPARATION OF STANDARDS

The two references by Perkin-Elmer Corporation provided information onpreparation of standards. The standards are required in order to calibratethe AA equipment. Theoretically, atomic absorption operates in accordancewith Beer's Law where concentration is proportional to absorbance. Inreality, this relationship deviates (not linear) due to such causes as straylight present or non-homogeneous temperature and space in the absorbing cell.A plot is, therefore, made of known concentrations versus absorbance for thestandards. This plot is then used with the actual samples to correlateabsorbance versus concentration.

Selection of number and concentration of standards appear to becomplex and vary appreciably with expected concentraions in the soil samples.Personnel with experience in this field were consulted, and it was decided touse nine standards for Ca++ and six standards for Mg++. See Table 16. Themagnesium standards were prepared by first weighing out 3-4 grams of Mg++ rib-bon and placing this into a flask. Concentrated HCL was poured into the flaskto wash off the oxidation residue from the ribbon surfaces. This process wascomplete when the color turned from shiny metallic to a dull appearance.Distilled water was then added to stop the reaction. The liquid was thenpoured out and acetone used to dry the ribbon. The ribbon was then air-dried,and 1 gram was placed in a clean flask. Next, 40 ml of (1 + 1) HCL solution(1 volume HCL to 1 volume distilled water) was made. This solution was added5 ml at a time until all of the Mg++ ribbon (1 gram) was dissolved--calledSolution 1. A separate solution, called Solution 2, was then made of (1/100v/v) HCL solution, by adding 10 ml concentrated HCL to 1000 ml distilledwater. It is noted here that the acid should always be added to the water,

" not vice versa, in order to avoid a violent reaction. Solution 1 was thenpoured into a 1000 ml flask; Solution 2 was used to rinse the remainingSolution 1 into the flask, and then enough of Solution 2 was added to the 1000ml flask to make 1 liter. This final solution was called the Stock Solutionfor Mg++ and was at a concentration of 1 g (Mg++)/liter of solution (or 1 mgper ml).

The standards for Mg++ were then prepared by adding various amounts ofthe stock solution to different amounts of distilled water to obtain dilutedsolutions of different concentrations. For example, 2 ml of stock solutionwere pipetted into a flask containing 48 ml of distilled water. This created asolution of 2 mg (Mg++) per 50 ml solution, or a concentration of 40 mg (Mg++)per liter.

The calcium stock and standards were prepared in a similar manner;however, calcium was used in a powder form vice metal to avoid a violentreaction upon addition of the HCL.

43

.- .-. .- _ - ". .-. -. ,. . . -. . . . - . .. . - - - . . 2 . . . -. •

D. ATOMIC ABSORBANCE TEST

Atomic Absorbance (AA) tests are predicated on the basis that allelements have a specific number of electrons surrounding their nuclei. Theatoms tend to be in a ground or stable state normally. The addition of lightenergy to the atoms will create an excited or unstable state as the energy isabsorbed while outer electrons become unstable. The atom will immediately tryto return to its stable stable, whereby, light energy will be released. Asthe number of atoms in the light path increases, the amount of light (of spe-cific wavelength) absorbed also increases. By measuring the amount of lightabsorbed at a specific wavelength, the amount of analyte (element in vapor)can be determined. Results of the AA tests are found in Tables 16-17.

The five basic components of the AA machine are a light source, absorp-tion cell, manochromator, detector to measure light intensity and amplify thesignal, and a display to show the readings. The type of machine used for thisproject was a Perkin-Elmer 560 Atomic Absorbance Spectrophotometer. A speciallight source is used as well. This consists of a Hollow Cathode Lamp specificto a particular element (e.g., Ca++ and Mg++). Basically, the lamp emits aspectrum of light (of specific element origin) which passes through theabsorption cell (flame) containing the sample vapor and is focused through amanochromator for light dispersion. The dispersed, isolated specific wave-length for the element goes to the detector which produces an electric current.The current is then processed by instrument electronics and the amount oflight attenuation or element absorbance is displayed. The function of theflame is to convert the sample aerosol (created from sample solution) intoan atomic vapor which can absorb light from the primary source (cathode lamp).The flame source can be either an air-acetylene mixture or a nitrous oxide-acetylene mixture. Air-acetylene was used due to the highly volatile natureof nitrous oxide-acetylene mixtures. One possible source of error can comefrom the sample element not being totally absorbed by the flame. For instance,magnesium absorption is interferred by the presence of silicon or aluminum.This can be eliminated by using a nitrous oxide-acetylene flame or by adding.1-1.0 percent lanthanum to the solution.

E. CALCULATION OF CONCENTRATIONS

A standard computer proqram provided by another graduate student(Tucker Green) was used with the Apple Computer to plot the standards anddetermine the various sample element concentrations. The concentrations ofCa++ and Mg++ in each sample are then adjusted by the dilution factors (400for Ca++ and 10 for Mg++). See Table 18. The actual percentage of Ca++ orMg++ in the soil is then calculated by dividing the adjusted concentrations bythe original concentration of soil solution (167 g/liter), then multiplyingthis by the percent of minus number 40 material (.42 mm in the soil). SeeTable 19.

F. X-RAY DIFFRACTION

X-ray diffraction analysis was performed on the samples (by Ron Methany)from Trenches 1 and 2 in order to determine the nature of calcium and magnesiumpresent, as well as any obvious trace elements. This process uses the spec-trometric pe-4der technique, where x-ray diffraction traces are made on mounted

44

samples. Material passing the number 40 sieve (.42 mm) was used to correlatefindings with the Atomic Absorbance tests.

The results of the test indicated large amounts of calcium present inthe form of carbonate, as well as silicons. Minor trace elements of potassium,iron, alumina, and magnesium were also evident. For the most part, the magne-sium could not be detected, due to extremely low content.

Photographs of the samples under spectrometric analysis are found inSection VIII-4, Figures 1-6.

G. UNCONFINED/TRIAXIAL COMPRESSION TESTS

Detailed procedures on these tests are found in Section IV of thisreport. In addition to performing standard tests, samples were wet then driedin order to look at some of the cementation effects.

4. TESTING RESULTS

Results of the atomic absorbance and x-ray diffraction tests are given inthis section in Tables 16-19 and Figures 1-6. Results of the unconfined andtriaxial tests are found in Section V, Tables 9-10.

45

TABLE 16ATOMIC ABSORBANCE RESULTS -STANDARDS

Element Concentration 3 Readings 3 Standard Deviations________ (mg/liter) _____________ _____________

Ca+3 .015/.015/.016 .0004/.0005/.00065 .022/.021/.022 .0011/.0006/.00047 .032/.033/.033 .0010/.0007/.0005

10 .038/.039/.039 .0010/ .0009/ .000920 .063/.066/.067 .0011/.0021/.002730 .106/.102/.109 .0036/.0024/.000940 .141/.142/.142 .0025/.0018/.004950 .196/.195/.199 .0041/.0040/.003360 .236/.243/.238 .0026/.0025/.0087

10 .378/.372/.373 .0041/.0035/.0057*20 .618/..612/.605 .0041/.0047/.0051

30 .759/.763/.758 .0057/.0044/.005440 .846/.844/.844 .0094/.0035/.004950 .903/.900/.904 .0029/.0037/.0054

60 .952/.949/.956 .0062/.0031/.0054

46

TABLE 17ATOMIC ABSORBANCE RESULTS -SA.MPLES

Element Trench Depth 3 Readings 3 Standard Deviations______________ Meters_(Feet)

Ca ~ T- 1.2-.(45 .108/.107/.103 .0024/.0024/.00411.2-1.5 (4-5) .097/.091/.092 .0041/.0045/.00392.6-2.9 (8.5-9.5) .148/.145/.148 .0053/.0039/.00432.6-2.9 (8.5-9.5) .164/.161./163 .0024/.0049/.00513.7-4.0 (12.13) .251/.248/.249 .0085/.0113/.00913.7-4.0 (12-13) .255/.251/.257 .0043/.0073/.0088

Ca++ T-2 1.2-1.5 (4-5) .056/.050/.053 .0020/.0016/.00221.2-1.5 (4-5) .055/.055/.055 .0024/.0024/.00202.6-2.9 (8.5-9.5) .052/.055/.051 .0012/.0014/.00152.6-2.9 (8.5-9.5) .051/.046/.049 .0017/.0016/.00173.7-4.0 (12-13) .112/.112/.109 .0027/.0026/.00293.7-4.0 (12-13) .107/.104/.108 .0019/.0030/.0032

Mg + T-1 1.2-1.5 (4-5) .571/.573/.575 .0101/.0049/.00661.2-1.5 (4-5) .523/.539/.532 .0053/.0047/.00462.6-2.9 (8.5-9.5) .534/.530/.529 .0083/.0031/.00802.6-2.9 (8.5-9.5) .571/.574/.558 .0045/.0037/.00653.7-4.0 (12-13) .610/.608/.610 .0105/.0050/.00523.7-4.0 (12-13) .628/.631/.623 .0055/.0050/.0055

Mg++ T-2 1.2-1.5 (4-5) .611/.613/.611 .0033/.0034/.00461.2-1.5 (4-5) .599/.602/.605 .0072/.0041/.0069

*2.6-2.9 (8.5-9.5) .596/.595/.591 .0069/.0035/.00322.6-2.9 (8.5-9.5) .568/.564/.560 .0051/.0040/.00233.7-4.0 (12-13) .545/.535/.539 .0042/.0089/.00403.7-4.0 (12-13) .523/.525/.524 .0029/.0063/.0032

47

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TABLE 18CONCENTRATIONS IN SAMPLES

Element Trench Depth Concentration Dilution Adjusted Concen.

_"_ Meters (Feet) (mg/liter) Factor (mg/liter)

Ca+ + T-1 1.2-1.5 (4-5) 28.3 400 11,320

1.2-1.5 (4-5) 24.8 400 9,9202.6-2.9 (8.5-9.5) 3q.5 400 15,8002.6-2.9 (8.5-9.5) 44.0 400 17,6003.7-4.0 (12-13) 67.9 400 27,1603.7-4.0 (12-13) 69.3 400 27,720

Ca++ T-2 1.2-1.5 (4-5) 13.9 400 5,5601.2-1.5 (4-5) 14.5 400 5,8002.6-2.9 (8.5-9.5) 13.4 400 5,360

2.6-2.9 (8.5-9.5) 12.9 400 5,1603.7-4.0 (12-13) 29.7 400 11,880

3.7-4.0 (12-13) 28.3 400 11,320

Mg+ + T-1 1.2-1.5 (4-5) 20.2 10 202

1.2-1.5 (4-5) 17.5 10 1752.6-2.9 (8.5-9.5) 17.5 10 1752.6-2.9 (8.5-9.5) 1c.9 10 1993.7-4.0 (12-13) 22.6 10 2263.7-4.0 (12-13) 23.9 10 239

Mg+ + T-2 1.2-1.5 (4-5) 22.8 10 2281.2-1.5 (4-5) 22.1 10 2212.6-2.9 (8.5-9.5) 21.6 10 2162.6-2.9 (8.5-9.5) 19.6 10 1963.7-4.0 (12-13) 18.1 10 1813.7-4.0 (12-13) 17.1 10 171

*1

TABLE 19ACTUAL CONCENTRATIONS - SOIL

Element Trench Depth Concentration -No. 40 Concen. in SoilMeters (Feet) (%) (%) (M)

Ca+ + T-1 1.2-1.5 (4-5) 6.0-6.8 83.9 5.0-5.72.6-2.9 (8.5-9.5) 9.5-10.6 85.1 8.1-9.03.7-4.0 (12-13) 16.3-16.6 89.7 14.6-14.9

Ca++ T-2 1.2-1.5 (4-5) 3.3-3.5 80.1 2.6-2.82.6-2.9 (8.5-9.5) 3.1-3.2 49.2 1.5-1.63.7-4.0 (12-13) 6.8-7.1 49.9 3.4-3.5

Mg++ T-1 1.2-1.5 (4-5) .11-.12 83.9 .09-.102.6-2.9 (8.5-9.5) .11-.12 85.1 .09-.103.7-4.0 (12-13) .14 89.7 .13

Hg+ T-2 1.2-1.5 (4-5) .13-.14 80.1 .10-.112.6-2.9 (8.5-9.5) .12-.13 49.2 .063.7-4.0 (12-13) .10-.11 49.9 .05

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5. DISCUSSION OF RESULTS

Climatic, geological, topographic, biological, and other physiographicconditions in the survey area were found to be ideal conditions for the for-mation of caliche. This included such conditions as acacia vegetation, flatland, runoff area (alluvial basin), semiarid region with past wet/dry seasons,falling water table, sandy soil with fines, evidence of past volcanic activity(igneous parent rock). This was further corroborated by extremely high N-values (up to 111 blows/foot) obtained in the Standard Penetration Test, aswell as physical conditions of the soil observed during laboratory and fieldtesting. This included grain-size distribution (sandy silt to sandy clayprimarily), color (white to reddish brown), nature of split-spoon samples(hard disc-shaped clumps), and consistency limits (low plasticity index witha liquid limit about that of portland cement-30 percent).

The atomic absorbance test results, Tables 16-19, show high concentrationsof calcium in Trench 1, which increases with depth (ranging from 5-15percent). Calcium is also present in Trench 2, but in lesser amounts (rangingfrom 1.5-3.5 percent). Magnesium is present in very small amounts, .09-.13percent in Trench 1 and .G5-.11 percent in Trench 2. The x-ray diffractiontest showed the calcium to be in carbonate form, as expected. Photographs ofthe samples, Figures 1-6, clearly show the calcium carbonate crystals clinging toquartz and other particles. The increasing content of calcium carbonate withdepth is also very apparent, as well as the higher content in Trench 1.

One of the primary tests performed to see the effects of cementation wasthe unconfined compression test. Cylinders were compacted at various watercontents and tested. Additional cylinders were compacted at similar watercontents, but allowed to dry for 72 hours. This time period was found to bethe optimum drying time to return the soil to its original hygroscopic moisturecontents, specific gravities, liquid limits, and plasticity indexes. Althoughthe top two sample layers are labeled SC and the bottom layer is labeled CL,both soils contain about the same amounts of sind and gravel with a slightincrease of the coarse sand in the top two layers and a slight increase ofclay-size particles in the bottom layer. These slight differences make ahairline distinction based on the Unified Soil Classification System. For allpractical purposes, the disturbed samples are considered identical. With thisin mind, the results of the tests can be compared.

The unconfined compression test results indicated that failure stressesincreased significantly during the cementation process. Although these stressincreases are to be expected for nearly any compacted soil as it dries, theincreases obtained for these soils were abnormally high, 300-5300 percentincrease. The cylinders essentially set up similar to small concrete cylin-ders. Another observation, in reviewing Tables 9-10, is that for a given soil(Trench 1-Three Depths) the peak failure stress increase varied directly withthe amount of cementing agent and amount of initial water content in the soil.It is also noted that the peak failure stress increased more in soil comprisedprimarily of silty sand than it did in soil comprised primarily of clayey sand.The silty sand had higher water contents, but less cementing agent. This oFcourse brings out the possibility of particle size and water content beingequally, if not more, important than the actual amount of cementing agentpresent. Additional tests would have to be perFormed to corroborate thishypothesis.

56

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Strains at failure were reduced by 20-92 percent during the cementationprocess. Higher reductions in strain were associated with increasingcementing agent and water content. Although the silty sand samples had highreductions in strain, no exact correlations can be made based on particlesize, since similar or greater strain reductions were achieved in the clayeysand soils.

Comparing peak failure stresses for the wet samples alone in the unconfinedand triaxial compression tests, the results indicate that for a given soil(e.g., Trench 1-Three Depths) the failure stress tends to decrease withincreasing water content and cementing agent. This is an important concept incaliche in that it shows a very real problem with wetting effects on this typesoil. This problem is discussed in the conclusions of this section.

One final observation is that there was a greater presence of calcium car-

bonate in the sands which contained greater amounts of fines, especially sandswith a large amount of clay-size particles. This, of course, could be due todifferent degrees of carbonate source present in the specific areas, but theclose proximity of the trenches tends to negate this reasoning. It is morelikely that the higher concentrations of calcium carbonate are found in sandswith greater amounts of fines due to the nature of calcite formation.Essentially, the calcium carbonate in solution has to leach through the soillayers slow enough to be able to adhere to the particles during evaporation(drying). Coarser soils would tend to drain the water too rapidly. Anotherpossible explanation is the process of calcite growth. Crystallization of thecalcium carbonate will occur more rapidly if particles are more closely spacedso that voids can be filled and the crystals can build on each other.

6. CONCLUSIONS

Several conclusions are evident in this study of caliche at White SandsMissile Range.

(1) Climate, topography, parent material, biological factors, andtime directly influence the formation of caliche. Each of these factors mustbe favorable to provide a source of calcium carbonate, water, proper soilgradation for leaching and adhesion, and evaporation. White Sands Missile Rangemeets these requirements and has an abundance of caliche within its subsoil.

(2) Higher N-values for the Standard Penetration Test are obtained inlayers of caliche due to the cementation of particles and correspondingincrease in densities (filling of voids with crystals).

(3) Flocculation is common in caliche during the hydrometer analysis,due to the cementation of the silt and clay-size particles. This was evidentduring the numerous hydrometer tests conducted on the borehole and trenchsamples. Additional tests for the minus 200 sieve-size faction (.074 mm)should be conducted in the areas of heavy cementation of fine material.Flocculation possibly can be prevented during these tests by the addition of20 ml of a 36 gm/liter silution of tetrasodium pyrophosphate, as suggested byF. Netterberg.

(4) Magnesium content can be difficult to obtain by the AA method

57

L,

if silicon or aluminum is present in the sample. This is normally preventedby using a nitrous oxide-acetylene flame or adding .1-1.0% lanthanum to thesolution. Neither was done in the AA tests run for this project; however, thelow concentrations of Mg++ are deemed correct due to the low concentrations olsilicon and alumina in the samples. The X-ray diffraction tests corroboratedthe low concentration of magnesium.

(5) The amount of calcium carbonate increases with depth due toleaching and increases with the presence of fines in the sand. This is due toa lower permeability increasing the calcium carbonate content during evapora-tion and the rapid formation of crystals in the smaller voids. It is also dueto the increased surface area available for adhesion, with the fines fillingvoids.

(6) Time is an important Factor in the strength of caliche. Forlaboratory cylinders, 72 hours was found to be optimum in returning the soilat any initial moisture content to its hygroscopic moisture content.Hygroscopic moisture content was selected in order to correlate results withthe compacted air-dry samples. Additional tests should be conducted allowingthe cylinders to dry at various time intervals, then testing them in uncon-fined compression. This could be used to develop a chart relating strengthincrease to initial moisture content and drying time (or final moisturecontent). Correlations could then be made of anticipated field strengthsbased on known wetting/drying periods and amounts of calcium carbonate.

(7) Strength increases significantly during the cementation process.The magnitude of increases in strength varies directly with the amount ofcalcium carbonate and initial water content in the soil. Although increasesin peak failure stress were found to be greater in sands containing high siltfactions than in sands containing high clay factions, more tests must be con-ducted to validate this hypothesis.

(8) Strains at failure are reduced by 20-92 percent during the cemen-tation process. The two key factors affecting this reduction are increasingcalcium carbonate and initial water content, which increase the magnitude ofstrain reduction. Particle size does not appear to greatly affect thereduction, as compared to these two factors.

(9) An important phenomena occurs in caliche soils upon wetting. Thecementation tends to break down and the soil loses much of its shear strength.The strength decreases more rapidly with increasing calcium carbonate con-centration and water content. This effect is probably due to the calcium car-bonate crystals returning to solution with the addition of water. If the soilonce again is allowed to dry, the crystals will reform. There was some evi-dence that the soil tended to increase more in strength after successivewetting/drying periods. This should be researched through further testing tosee if there is an optimum number of successive wettings for strengthincrease. This information could also be used to correlate strength proper-ties with soils in the field based on past wetting/drying periods.

(10) The AA test is a relatively simple method of obtaining con-centrations of calcium or magnesium in the soil; however, it is limited. Thetest does not tell the nature of the compounds. The X-ray diffraction testshould be used in conjunction with the AA test in order to determine whetherthe compound is a carbonate, silicate, or sulphate. Additionally, X-raydiffraction can determine tract elements if these are of concern.

B5•

SECTION IX

SUBSURFACE SEISMIC INVESTIGATION

1. INTRODUCTION

During the summer of 1982 a total of twelve seismic refraction surveys were

conducted at the Mill Race test site, White Sands Missile Range, New Mexico.The purpose of these surveys was to establish the depths to various soillayers and to determine subsurface seismic velocities. The seismic surveysare part of a site characterization survey for the Air Force WeaponsLaboratory (AFWL), Kirtland AFB. The depth of investigation, established byAFWL, was approximately 10 meters (32 feet).

In the investigation area five boreholes were drilled and two trencheswere excavated. The trenches were used to obtain bulk samples of soil for

laboratory testing as described in Section III, paragraph 4, and Section IV.At each of these locations a seismic survey was conducted. Five additionalsurvey points were chosen. The location of these five points was based onpreliminary soil data obtained during the boring operation and trench excava-tion process. Appendix F shows the location and direction of each seismicline.

'4

Data from the borings indicated an irregular interface between underlyingsoil layers. Time versus distance plots based on data from the seismic surveysconfirmed this. The method chosen to determine the depth of interface and thesubsurface seismic velocities, is contained in a September 1975 Technical Noteby Hideo Masuda, "Practical Method of Seismic Refraction Analysis for EngineeringStudy." Excerpts from this study were made into class notes for CE 461, SoilEngineering for Highways and Airfields.

Results from the seismic surveys in conjunction with data from thelaboratory tests will be used in this report to iddntify the type of soil pre-sent and its strength parameters. AFWL weapons effects personnel will also usethis data to predict soil response during future tests.

2. STATE OF THE ART

Of major concern at the Mill Race test site was the location of calichelayers. Depending on its thickness, strength and density, caliche can adverselyaffect the anticipated results of weapons simulating tests. Energy waves gen-erated through the soil by the blast can be deflected in random directionsrather than in predicted directions. Waves can be suppressed or magnifieddepending on the properties of the caliche.

Shallow seismic refraction surveys have found increasing application inmaterials surveying and other work around the world. The shallow refractionmethod has been successfully applied to caliche identification in South WestAfrica. This method is best suited to determine rippability, consistency and,as used in this report, a supplement for drilling. Hard layers of caliche areusually underlined by a finer powder caliche. This material has a lower seismicvelocity and is not detected by the seismic refraction method. The surveys inAfrica produced varying results on seismic velocities in caliche. Table 20lists velocities for different types of caliche.

59

TABLE 20. SESIMIC VELOCITIES OF VARIOUS TYPES OF CALICHE

MATERIAL TYPE SEISMIC VELOCITY (m/s)

Hardpan Caliche 1200 - 4500

Honeycomb Caliche 900 - 1200Nodular Caliche 600 - 900Powder Caliche 400 - 1000Calcified Sand 450 - 1200

Caliche is also found by a study of its relation to topography. Hardpan

caliche often occurs on rises of cemented alluvial or pan terraces. Calichewith the lowest Plasticity Index will normally be found on rises or slopes. Thehardness of a caliche usually increases with the distance of the terrace fromthe feature. Gaps of non-calcified material may exist between terraces. Iareas where granite is present, such as in the north section of WSMR where MillRace is located, caliche is usually associated with basic igneous rock such as

dolerite or basalt or other lime-rich rocks.


A. Library Search

Prior to visiting the Mill Race site several technical reports per-taining to the site and to the south west part of the United States in generalwere reviewed. These reports contain data from seismic tests conducted at WSMRand at sites with similar soil deposits.

Reference 10, Geological Influences on Nuclear Weapons Effects inWestern Alluvial Valleys, pages 46 to 49 and 73 - 74, provides data and infor-mation for the southwest part of the United States in general. The followingtypical seismic velocities for soil and rock were provided in this report.

TABLE 21. TYPICAL SEISMIC VELOCITES FOR SOILS AND ROCK

MATERIAL SEISMIC VELOCITY (m/s)

Loose and dry soil 180 - 1000Coarse and compact soils 900 - 2600Cemented soils 900 - 4300Limestone 2100 - 6400Igneous Rock 3000 - 6700

Strength and inertial properties of the site material are the parametersthat establish the nature, intensity, and velocity of advance of the groundmotion generated by a nuclear event. Usually in soils and rocks the higher thedensity the higher the velocity because the denser material is more resistant todeformation. Boundaries (caliche layers) at which material properties changeabruptly can drastically alter the nature of the motion by creating new wavessuch as strong surface waves. Cementation can increase density by as much as 20

percent and can double seismic velocities. Caliche does have some good proper-ties for weapons testing. Caliche cemented alluvium produces a more competentmediumi for cratering which results in reduced ejecta. Howt."er, massive cemen-tation also influences the size of the ejecta particles. Louse, minimally

cemented alluvium will generate ejecta particles no larger than in-situ sizematerial. With caliche present the size of the ejecta particles increases dra-matically.

-'I - t. A-

Ground motion, one of the properties measured during the Mill Race event, is

strongly influenced by the properties of the material through which it propaga-tes. The reaction of the material governs both the magnitude of the motion at aparticular point and the attenuation of effects with depth and range. Dependingupon the soil present at a test site, ground disturbances may arrive at a pointof interest prior to the arrival of the airblast. These early disturbancesresult from air-induced energy propagating ahead of the airblast wave in thesurface layer or from energy which has been refracted into a soil layer that isfaster than the one you are testing. The location of dense fast layers of soil

or very loose layers are of special interest to weapons effects personnel as

they can alter anticipated experiment results.

A second report that was reviewed was reference 2, a summary of the Geologic

Characterization of the Mill Race Site, WSMR. This report was prepared by theNew Mexico Engineernig Research Institute as part of the site selection process

for Mill Race. Four potential ground zero sites were investigated. Fifteenseismic refraction lines were run during this investigation. Only one, line 13,was run at the site where the Mill Race event was conducted. Data from thisline showed a seismic velocity of 822 meters per second (2697 fps) for soil downto a depth of 60 meters (198 feet). The spacing of the geophones did not allowfor more precise measurements at shallower depths. Each line was approximately640 meters (2110 feet). One half of the line was made up of 12 geophones spaced15 meters (50 feet) apart. The other half had geophones spaced 34 meters (110feet) apart. The seismic velocities obtained during the site selection processagrees with the results obtained during our survey, which are presented inparagraph 4 of this section of the report.

A third report reviewed was reference 3, Soil Sampling and Downhole SeismicSurveys at the Pre-Direct Course and Direct Course Sites, WSMR. The DirectCourse Site is located in the north central section of our 2.59 kilometer squarearea. The Pre-Direct Course area is located between our bore holes one andfour. Seismic velocities for the first two meters of soil averaged 550 meter-per second and for the next seven meters they averaged from 780-1155 meters po.second. Borings in the area showed a silty sand down to one meter, caliche fromone to three meters, gravelly sand from three to five meters and alternatinglayers of similar material down to 18 meters.

B. Seismic Field Test

Twelve seismic refraction surveys were conducted at the Mill Race Site. Ateach location two 36 meter (120 foot) seismic lines were run. Therefore thetotal line length at each location was 72 meters (240 feet). Each line wasreversed (shots recorded on both ends). This is required by Hideo Masuda in hisTechnical Note mentioned in the introduction to this section. The geophonesused were Walker Hall-Sears type Z-3 with a natural frequency of 4.5 hertz. Thegeophones were recorded by an SIE RS-44, 24 channel seismic amplifier. Eachgeophone was placed five feet apart. Energy was supplied by striking an allumi-num plate on the ground with a 16 pound hammer

The seismic amplifier was located in a camper on the back of a pickup truck.

Two lines from this unit, each with 12 geophones, were run along the ground.The aluminum plate was placed five feet from the end of the line. Next to

the plate, another geophone was placed. This geophone sent a signal to therecorder that the plate had been struck. Two readings were taken at each end ofthe 36 metyer (120 foot) line. The north 36 meter side of the line was always

61

run first. After it was completed the geophone lines were moved to the south 36meter section and the same process was repeated.

Several problems were encountered with military aircraft practicing over the

site and with drilling operations at the Pre-Direct Course Site. The amplifier

and geophones are very sensitive to noise. Three sets of readings producedunreliable results. These were at locations B-1 south, B-3 south and B-5 south.Time versus distance plots for soil with irregular interfaces produce lines withvarying slopes. Plots for the three locations in question produced lines thatwere even more irregular. The data from these runs could not be used in this

survey.

C. Calculations

The following data sheet and graphs, Figures 8, 9 and 10 are representative

of the calculations for all twelve sites. The calculations for the remaining 11sites are contained in Appendix IX-A of this section. All calculations are as

shown in Hideo Masuda's Technical Note, referenced in the introduction to thissection and as taught in CE 461, Soil engineering for Highways and Airfields.They are the basic equations used to determine velocities and depths to inter-face for irregular surfaces.

The first step in determining velocity and depth is to plot time versus

distance (See Figure 8). These data are taken directly from the printedreadout of the seismic amplifier. The time that the energy source takes to gofrom the metal plate (point p) to each geophone (point A) is Tag or on the

reverse run Tb . The time the energy source takes to go from the plate to thelast geophone ftotal travel time) is Tab. This value is averaged if the time

varies between the first run and the reverse seismic run. Ta and Tbp are

then plotted versus time. A best fit line is drawn between tgese points. The

slope of these two lines is the seismic velocity of the second layer, V 2.V2 values are then averaged (See Figure 9). V1 values are determined by

taking the slope of the first sloping line ol Figure 8. These values are alsoaveraged. The ratio of VI to V2 is used to determine as shown in Figure

10. In Figure 10, ta and tbp are the times corresponding to the intercept ofthe two V2 lines in Figure 9 with the vertical axes. These two times are usedto calculate ha the depth to the underlying irregular surface under point A,hb the depth from point B to the irregular surface and hp the depth to the

irregular surface under the remaining geophones. The depths ha and hb and

hp are measured perpendicular to the irregular surface as shown in Figure 7.

A P B

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4. RESULTS

TABLE 22No SEISMIC RESULTS

Velocity (m/s)Location Layer I Layer 2

B-i (north) 381 709B-2 (north) 469 1086B-2 (south) 530 827B-3 (north) 415 882B-4 (north) 360 842B-4 (south) 397 937B-5 (north) 386 981T-1 (north) 411 942T-1 (south) 343 871Pt.-A (north) 463 Q76Pt.-A (north) 523 938Pt.-B (north) 394 837Pt.-B (south) 425 871Pt.-C (north) 381 892Pt.-C (south) 442 868Pt.-D (north) 404 1025Pt.-D (south) 391 1057Pt.-E (north) 457 793Pt.-E (south) 381 805Pt.-F (north) 383 881Pt.-F (south) 460 938

Figures 11A through F, show the underlying irregular sur-faces for each seismic location. In theory archs should bestruck off at each hA, hB and hp depth. A french curve wasused in these figures for aesthetic reasons only.

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5. DISCUSSION OF RESULTS

Seismic velocities for the first layer of soil varied from 343 meters per

second (1125 fps) to 530 meters per second (1740 fps) as shown in Table 22,with an average of 420 meters per second (1380 fps). This compares to 550meters per secord determined during the Pre-Direct Course Site survey.Surface soil a- each seismic site varied from a low density silty sandymaterial to a very loose silty sandy material. A significant amount of orga-nic material, from plants and animals, was also present in the first layer.During the seismic survey and seven days prior to it, no rainfall was recordedat the site. Table 21 provides typical seismic velocities for various typesof soil and rock. Layer 1 at the Mill Race Area is typical of the loose anddry soil in Table 21 with a velocity range of 180-1000 meters per second.

Seismic velocities for layer two varied from 709 meters per second (2330fps) to 1086 meters per second (3560 fps) as shown in Table 22, with anaverage of 905 meter per second (2970 fps). This compares to 780-1155 metersper second found during the Pre-Direct Course survey. According to Table 21for typical seismic velocities, layer two falls into one of two groups, coarseand compact soils with a velocity of 900-2600 meters per second or cementedsoils, 900-4300 meters per second. Table 20, that presents velocities forvarious types of caliche, has three categories that our soil could fit into:honeycomb caliche, 900-1200 meters per second; powder caliche, 400-1000 metersper second; and calcified sand, 450-1200 meters per second. All three typesof soil have been identified in the reports discussed in the library searchportion of this section, as being present in the Mill Race Test Area. Our ownsoil classification, Table 7, identifies most of the soil in the Mill RaceArea as silty sand or clayey sand. Blow counts from Table 2, averaged 20blows per foot for the first 1.4 meters (4.5 feet) and over 50 flows per footdown to 9.8 meters (32 feet). 20 blows per foot is indicative of medium densematerial and 50 blows per foot indicates very dense material.

"* During the trench excavation a white to very light pink layer of soil wasobserved to begin at a depth of 1 meter. Its texture, color, density (in thislayer the back hoe experienced difficulty in excavating the material) iden-tified this soil as caliche. Section VIII of this report identifies the che-mical composition of the soils that were tested. This section also confirmsthe presence of cabonates which is essential in the formation of caliche.

Eight miles to the east of the site are the Oscura Mountains. Largedrainage patterns can be observed starting at the base of the mountains andheading toward the Mill Race Site. The irregular surface pattern of thesecond soil layer identified was caused in part by runoff in the test area.Much of the surface soil is with some organic material. Over time it hasfilled in the low lying areas and left this irregular subsurface layer.Arroyos are also present in the area. The boring at location four shows asizeable amount of gravel. The seismic line for this location produced a con-cave surface for the second seismic layer. This same result can be seen inseveral plots of Figure 11A to F.

6. CONCLUSIONS

Previous seismic surveys conducted in the Mill Race Test Area producedvelocities up to 550 meters per second for the first layer of soil and from780 to 1155 meters per second for the second layer of soil, down to a depthof 15 meters.

73

(1) Typical velocities for the first soil layer compared to previous seismic

surveys. Velocities up to 530 meters per second were obtained during thissurvey.

(2) Typical velocities for the second soil layer also compared with pre-vious seismic surveys. Velocities between 709 and 1086 meters per second wereobtained.

-" (3) Equations for an irregular surface from CE 461, Soil Engineering forHighways and Air Fields based on a September 1975 Technical Note by Hideo

*- Masuda, are valid for reducing data obtained at the Mill Race test site.

(4) The seismic survey produced an accurate picture of the underlying irre-'ular surface.

(5) The seismic survey also confirmed the results of the laboratory tests,both chemical composition and standard classification tests.

(6) Velocities for the second layer are indicative of typical velocities

for caliche.

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APPENDIX B

UNCONFINED COMPRESSION TESTS ON SOIL

SAMPLES AIR-DRIED FROM VARIOUS INITIAL WATER CONTENTS

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167

a7-- - -

96-0

zw

,4

Cj

I-n

ale.

0 00

a a a 0P0 0 0 0

0o 00 00' ~~ZMIN~tSSTUJS VOIVIA~a-

168

-~ - -7

co W/NX~ n3US SOfVIA3G '

169

APPENDIX C

UNCONFINED COMPRESSION TESTS ON SOIL

SANPLES AT VARIOUS WATER CONTENTS

Q -.

ONN

____ ____ __ __0

zm/N- SSHHS IO.VIAN

171N

z

coc-

ZM/.)lSMI HOVIA

0172-

L0

z '

CD

173,

. .. -.

FT,z -

tall

- --

__._ 0.

..

•- 0

p"i-

-. '7 .,-:wr- s"i ioJvIo

,I- g / S ,, O,. IA O

? ,,174

APPENDIX D

TRIAXIAL COMPRESSIONJ TESTS ON AIR-DRIED SOIL SAMPLES

175

-I--.

550

_______________500

4.50

400

_____________________ _______ _______350

300120.66 finm

2

(17.5 psi

_______ _______ _______250

86.l19 kN mn2

(12.5 Ps

________ 00

150

_____________ ______ ______ ______ ______ 100

1.71 kN/12 TRIAXIAL COMPRESSION TEST7.5 psi) AIR DRIED SOIL

Ti (1.22-1.52mn)50

00 2 4 6 8 10 12 14 16 18

176

m 600

34.0 155o

________ 500

450

" q6120.66 kI /m2

(17.5 ps

350

________ 300

86.19 k-,/m2

(12.5 psi)

200

150

1____00

51.71 kN m2 TRIAXIAL COMPRESSION TEST

(7.5 psi AIR DRIED SOIL

Ti (2.59-2.90)

50

- - 00 2 4 6 8 10 12 14 16 18

E17

v.-: 177

m --- - 00

- -- -550

S32.4 0

500

______________450

-400

________350

300

250 E

- - 200

- _____ 100

51.71 N~m2 RIAXIAL COMPRESSION' TEST

(7.5 si,'IR DRIED SOIL1i (3.66-3.96m)

50

00 2 4 6 8 10 12 14 16 18

Q

178

- -- - - - - - 600

______________________550

_______ _______ -500

________________450

120.6 kN/m 2

(17. psi)

- -400

________350

_______ ______ _______300

86.19 k /r2

(12.5 p i)

220

________150

51.71 k~j2(7.5 psi)

_____________________100

TRIAXIAL COMiPRESSION TESTAIR DRIED SOILT2 (1.22-1.52mn)

______________50

- -- -

0 2 4 6 8 10 12 14 16 1s

179

_______ _______ _______ _______550

500

120.66 tN/rn2 450(17.5 p-i)

- - 350

86.19 kN l2(12.5 Ps

300

ool 34.4

51.71 kN/rn2

(7.5 psi)

_______150

100

TRIAXIAL COMPRESSION TESTAIR DRIED SOIL

_____T2 (2.59-2.90n)

50

- 00 2 4 6 8 10 12 14 16 18

180

-" . " - " ._" -." -i' .' - -°

. L..m-f l-

- -.- --' ." -. -" . -. ..- . ... -.-... .

600

550

- .500

4-50

-400120. 6 kN/m 2

(17.5 psi)

_ _1350

300

86.19 f/M2

(12.5 p i) -250

(P 34.8"

-.- 150

51.71 kN/m2

(7.5 si)

50TRIAXIAL COMPRESSION TESTAIR DRIED SOILT2 (3.66-3.96m)

C-o

* .--

. 0 4 6 8 10 12 14 16 18

.81

.'

5% 181

.

'.4q

APPEND IX E

- TRIAXIAL COMPRESSION TESTS ON SOIL

SAMPLES AT VARIOUS WATER CONTENTS

182.

1--

' ()

:)

w

(\J 8 ........

z .!<

:

90

0

80

0

70

0

60

0

~500

N

::r:

8 ({) tS4

00

8 <

H

>

ril

A 3

00

20

0

100 0

I I I 0

(

r 51.7

1 kN

/m2

86

.1

(7.5

p

si)

( 1

2.

W=

9.6%

W

=

2 4

6 0

2 ' '

kN/m

2 p

si)

9.

6%

i

4 EJ

6

d

j

6 0

I

-v

I'-

I

J I

120

66

kN/m

(1

7

5 p

si)

W

= 9.

6%

TR

IAX

IAL

C

OM

PRE

:iSIO

N

TE

ST

~OMP

ACTJ

<.:D

W

ET

r1(1

.22

-1.5

2 m

)

2 4

6

* . * . . .v

F0..

% 'A

0.0

co 04

184

L.J

04

- - ___________ co

)d -'

m co en

Z-/N-4 ~ ~ ~ SSISNdII

1085

,WI-

____ __ _ ____ ___ ___

C 0C_ _ _ _8 - c~C_ _

zm/N~ SSUI

186 u~

* N A

4-

--- -

z(N

(N

O~eJ________ .~ (I(-. U

* *001~-

______ - -7

- - __________ 0

(N

t

(NI ~-

-. ~4______ .~ ~.H

- - - - .7OU~-*0

* e.i -40 - N~ .-

- ___________ - - - ___________ 0

(NI

- .-

H_______ - .7

?-. U~ 0

-(N,J.~ .- ~

- - - 0

0 0 0 0 0 00 0 0 0 0

.7 4*~ (N -~U/N4 SS~IJ.S ~IOI.YIA3a

187

* -. . *- ~ -

I-T

0I0

It X4

ZMAM SM SHJ.I~

- - -188

.4 lIEU liii ~ --

I - -

I-.

I-

zCd,

N- - ____ - ____

= I

-~

* *0or-- -~N- fl

-

-- ____ ____ -- ____ 'C N

Z CN 'JJ'C

- *0* N -

- - ___ ___ 4-,

- -

*1~

* V - - - -

'I-.

N

a- -- _______ - _______ -N

C. ~C

- ___ - - ___ 4-,

- - - - - C

8 8 8 8 8 0 0 0N 40 Id, 4-4 N -

~m/~4 SS~~S ~OIvIA3a

189

-'I

~ - - - -

I-cia

I.-

ciaU,

'.4_____ _____ ~ ~

-. 4.) -b.- 001 -

.o.r~ -U.

oa~'.4- .-

~ 0-

'.1______ ______ U-. ______ ______ 0

- -. - #4zw.~ a.14~.ia .

~0- a~ - 3

_ -

U.,

a______ =

0.4~~'..Uc 4.4

- ~- H

si~4'-~ 3 U.,

- - - 00 e e o o

U., 0

~~/r4~ ssaH.ts ~o1viAaa

I190

-4

-- -. .......................- * -

~kn. .

101

----

f.4 r-

Zm/NMSMIS OVIA

191-

II-

14,

cl,~U %QC-

1922

---- - --

I-

z

U, -~.

~ N

_______ _______ _______ _______ N

N

NE

N.

.~ ~ N~- -~.

- N Ii~ -.

_______ _______ _______ N

m in C

o 0 0 0 0 0 0o o 0 0 0 0N -

193

N . - ~., xz.. z. ~.. x -

464

C-4 -

Ufn

a, LA

101

194

APPENDIX F

SITE PLAN, WHITE SANDS MISSILE

RANGE SURVEY AREA

"9 5

42.

.o

-. 3

*2

-105..

- ~ I.-.

IL I -

196

* " , . .- _ . . - - . .. -b T .--- -

REFERENCES

1. AMEND, ULLRICH and THOMAS, Have Host Cylindrical In-situ Test (CIST) DataAnalysis and Material Model Report, (AFWL) DE-TN-77-005, Kirtland AirForce Base, New Mexico, March 1977.

2. BEDSUN, DAVID A., A Summary of the Geologic Characterization of the MILLRACE Site, WSMR, Air force Weapons Laboratory, Kirtland Air Force Base,New Mexico, June 1981.

3. BEDSUN, DAVID A., Soil Sampling and Dovnhole Seismic Surveys at the Pre-Direct Course and Direct Course Sites, WSMR, Air Force Weapons Laboratory,Kirtland Air Force Base, New Mexico, May 1982.

4. CALHOUN, D.E. and TRIANDAFILIDIS, G.E., 7th Proceedings of theInternational Conference of soil Mechanics and Foundation Engineering,Dynamic Oedometer Study of Lateral Yield Effects, 1969.

5. EM 110-2-1906, Engineering and Design Laboratory Soils Testing, Head-

quarters, Department of the Army, Office of the Chief of Engineers,30 November 1970.

6. HESSE, P.R., A Textbook of Soil Chemical Analysis, Chemical PublishingCompany, Inc., New York, 1972.

7. LAMBE, T.W., Soil Testing for Engineers, Massachusetts Institute ofTechnology, John Wiley and Sons, Inc., New York, London, Sydney, 1967.

8. LAMBE, T.W. and WHITEMAN, R.V., Soil Mechanics, Massachusetts Institute ofTechnology, John Wiley and Sons, New York, London, Sydney, Toronto, 1969.

9. MECHTLY, E.A., The International System of Units, Physical Contants and'Conversion Factors, NASA SP-7012, National Aeronautics and Space Administr-ation, Washington D.C., 1973.

* 10. MELZER, SCHENKER, HULCER and RINEHART, Geological Influences on NuclearWeapon Effects in Western Alluvial Valleys, AFWL-TR-78-155, Kirtland AirForce Base, New Mexico, June 1979.

11. MIL-STD-619A, Unified Soil Classification System For Roads, Airfields,Embankments and Foundations, 20 March 1962.

12. PERKIN-ELMER CORP, Analytical Methods for Atomic AbsorbtionSpectrophotomethry, Norwalk, Connecticut, January 1982.

13. PERKIN-ELMER CORP, Instructions Model 560 Atomic AbsorbtionSpectrophotometer, Norwalk, Connecticut, April 1979.

14. POR 7072, MISTY CASTILE Series, MILL RACE EVENT, Test Execution Report,WSMR, Defense Nuclear Agency, Washington D.C., 18 December 1981.

1 97

(References Continued)

15. SANGLERAT, G., The Penetrometer and Soil Exploration, Interpretation ofpenetration diagrams-theory and practice, Elsevier Publishing Company,Amsterdam, London, New York, 1972.

16. TERZAGHI, K. and PECK, R.B., Soil Mechanics in Engineering Practice, JohnWiley and Sons, New York, Chichester, Brisbane, Toronto, 1967.

17. WELLS and SCHULTZ, Properties and Prediction of Caliche in Alluvial Basinsof the Southwestern United States, AFOSR-78-3572, Air Force Systems Command,USAF, Bolling Air Force Base, Washington D.C., July 1980.

198

soil characterization and evaluation w mexico14 moh's hardness scale 40-15 amount of soil used...

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