A1-2a RB Geotech Report.pdf

Submitted to:

Submitted by:

SITE EXPLORATION AND

GEOTECHNICAL ENGINEERING REPORT

PROPOSED TRACKER MOUNTED ARRAY

ROSEBUD IHS HOSPITAL

ROSEBUD, SOUTH DAKOTA

(Twin Rivers Testing #2014-154)

TWIN RIVERS TESTING & ENVIRONMENT AL, LLC

KenKaskie President

Geotechnical Engineer:

enior Geotechnical Engineer Mr. James A. Bertsch, P.E. NE E-6985 Certified Testing Services, Inc.

October 20, 2014

Twin Rivers Testing #2014-154

TABLE OF CONTENTS

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

EXECUTIVE SUMMARY ........................................................................................................... i

INTRODUCTION

PROJECT DESCRIPTION

FIELD INVESTIGATION

LABO RA TORY INVESTIGATION

SITE AND SUBSURFACE CONDITIONS

SUBSURFACE PROFILE

GROUNDWATER

GEOTECHNICAL EVALUATION

SITE PREPARATION

NON-STRUCTURAL FILL

EXCAVATIONS

UTILITY TRENCHING

SEISMIC DESIGN CONSIDERATIONS

DRAINAGE

CONSTRUCTION DETAILS

APPENDIX I-FIELD INVESTIGATION

Keys to Symbols Boring Location Diagram Boring Logs

APPENDIX II - DEFINITIONS

EXECUTIVE SUMMARY

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

An exploration and evaluation of the subsurface conditions has been completed for the proposed Tracker Mounted Array to be installed at the Indian Health Services (IHS) Hospital in Rosebud, South Dakota. Twin Rivers Testing understands that the project will consist of constructing twelve Tracker Mounted Array Solar units in an area 154 ft. by 219 ft. that is located northwest of the IHS Hospital. In general, the subsurface conditions identified by the borings included Sandy Lean Clay, Clayey Sand and Poorly Graded Sand with Clay.

Twin Rivers Testing understands that the proposed solar panels will to be supported by a helical pile foundation systems installed to a depth of ten feet below existing grade. The attached boring logs should be supplied to the helical pile contractor to determine the depth of the helical piles. The lateral bearing pressures in the following table may be used for the material at the site.

MATERIAL LATERAL BEARING PRESSURE (PSF)

Sandy Lean Clay* 180

Clayey Sand and Poorly Graded Sand 250 *Should be neglected due to frost action

THE EXECUTIVE SUMMARY HAS BEEN PREPARED TO PROVIDE A GENERAL

OVERVIEW AND SHOULD NOT BE RELIED UPON FOR ANY OTHER PURPOSE. ALL

INFORMATION ABOUT FINDINGS, RECOMMENDATIONS, AND OTHER CONCERNS CAN

ONLY BE FOUND IN THE FULL REPORT.

INTRODUCTION

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

Twin Rivers Testing & Environmental, LLC (Twin Rivers Testing) has completed the geotechnical engineering services for the proposed solar panel foundations to be constructed at the Rosebud IHS Hospital in Rosebud, South Dakota. Twin Rivers Testing's services were authorized by

The main purpose of this exploration was to explore the subsurface conditions at the site to provide information for the proposed helical pile foundation design.

PROJECT DESCRIPTION

Project information was provided by time of the soils exploration. Twin Rivers Testing understands that is constructing the Solar Tracker Mounted PV Array system at the Rosebud IHS Hospital. Twin Rivers Testing's report is based on the following conditions:

Structure

• Helical Anchor Installations

• Installation Depths of 10 ft.

Grading

• Approximately one foot of cut/fill required to bring site to grade

The geotechnical recommendations presented in this report are based on the available project information, structure location, and the subsurface materials encountered in the borings at the time of this exploration. If any of the noted information is incorrect, please inform Twin Rivers Testing so that we may amend the recommendations presented in this report if appropriate and if desired by the client.

Twin Rivers Testing will not be responsible for the implementation of its recommendations when it is not notified of changes in the project.

FIELD INVESTIGATION

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

The site subsurface conditions were explored with two soil test borings performed at the proposed site to depths of 15 feet below ground surface. The boring locations and depths were determined by Twin Rivers Testing. The borings were drilled using a truck-mounted drill rigusing41

/ 4 hollow stem augers. Soil samples were routinely obtained during the drilling process using standard penetration test samplers (ASTM D 1586).

Field logs were prepared for the borings. The logs contain visual classifications of the materials encountered during drilling as well as an interpolation of the subsurface conditions between samples. Final logs, included in Appendix I, represent Twin Rivers Testing's interpretation of the field logs and may include modifications based on laboratory observations and tests of the field samples. The final logs describe the materials encountered, their thickness, and the locations where samples were obtained. The boring was backfilled with auger cuttings prior to leaving the site.

The field investigation was undertaken to develop engineering information directed solely to

· meet the purposes as defined in the "Introduction." The intent of these services was not to uncover or identify any contaminated subsurface material that may contain hazardous or flammable substances. Identification of such substances requires specialized exploration techniques and analyses that were not employed in this exploration. Any statements in this report or on the boring logs regarding odors, colors, and unusual or suspicious items or conditions are strictly for informational purposes.

LABORATORY INVESTIGATION

Field samples obtained from the borings were returned to Twin Rivers Testing's laboratory where they were visually classified and logged. Selected soil samples were tested in the laboratory to obtain material properties for the preparation of this report. Laboratory testing was accomplished in general accordance with ASTM procedures. The following laboratory tests were performed on selected soil samples:

Natural water content (ASTM D 2216) (9) Unconfined Compression (ASTM D 2166) (1) No. 200 Sieve Wash (ASTM D 1140) (4) Atterberg Limits (ASTM D 4318) (1)

Test results were utilized in the development of geotechnical evaluations and recommendations.

Twin Rivers Testing #2014-154 Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

SITE AND SUBSURFACE CONDITIONS

The site is currently an undeveloped area located in the northwest side of the Hospital property. The site is an empty lot that was previously cleared of trees prior to our site visit. The site surface was firm and the drilling equipment did not experience difficulties in moving around the site.

SUBSURFACE PROFILE

Samples of the material encountered in the borings were classified as Sandy Lean Clay (CL), Clayey Sand (SC) and Poorly Graded Sand with Clay (SP-SC). These types of soils typically behave with a low swell potential. In general, the consistency of the Sandy Lean Clay was stiff, the density of the Clayey Sand was very loose to dense and the density of the Poorly Graded Sand with Clay was medium dense to dense.

The above subsurface description is of a generalized nature to highlight the major subsurface stratification features and material characteristics. The boring logs included in Appendix I should be reviewed for specific information at individual boring locations. These records include soil descriptions, stratifications, penetration resistances, locations of the samples, and laboratory test data.

The stratifications shown on the boring logs represent the conditions only at the actual boring locations.

Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be gradual.

GROUNDWATER

Groundwater was not encountered in the borings during drilling on August 27th , 2014. Twin

Rivers Testing expects that construction activities will be performed above the water level and groundwater will not be a factor during the construction activities. It should be understood that the level of the groundwater might fluctuate during construction or at other times of the year depending upon climatic and rainfall conditions. Additionally, discontinuous zones of perched water may exist prior to encountering the free groundwater within the overburden materials.

GEOTECHNICAL EVALUATION

The following geotechnical related evaluations have been developed on the basis of the subsurface conditions encountered and our understanding of the proposed construction. Should changes in the project criteria occur, a review must be made by Twin Rivers Testing to determine if modifications to our recommendations will be required. The boring logs depict subsurface conditions only at the specified locations on the site. The attached boring logs should be provided to the helical pier contractor for determining the depth of the helical piles.

MATERIAL

Sandy Lean Clay*

Clayey Sand and Poorly Graded Sand *Should be neglected due to frost action

SITE PREPARATION

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

LATERAL BEARING PRESSURE (PSF)

Twin Rivers Testing recommends that organic material, and unsuitable soils in the construction area be stripped from the site and either wasted or stockpiled for later use in landscaping, if site grading is performed. A representative of the geotechnical engineer should determine the depth of removal at the time of construction.

After sub grade preparation and observation have been completed, fill placement, if required, may begin. Fill materials should be a granular material or lean clay free of organic or other deleterious materials, have a maximum particle less than 3-inches, and have a liquid limit less than 45 and plasticity index less than 22. Fill materials should not contain frost and new fill should not be placed on frozen ground.

Structural fill should be placed in maximum loose lifts of 4 inches for hand compaction equipment and 8 inches for riding compaction equipment and compacted to at least 95 percent of the materials' standard Proctor maximum dry density. Backfill for foundation excavations should be compacted to a minimum of 95 percent. Lean Clay should be compacted to within minus 3 to plus 3 percent of the optimum moisture content in general accordance with ASTM D 698 procedures. For non-cohesive fill, compaction should be at a relative density between 70 and 100 percent as determined by ASTM D 4253 and D 4254 at over 95 percent saturation. The moisture content of the material should be maintained between the recommended moisture contents until concrete is placed on the material. Each lift of compacted-engineered fill should be tested by a representative of the geotechnical engineer prior to placement of subsequent lifts.

The on-site Sandy Lean Clay and Clayey Sand materials appear suitable for use as structural fill. However, all fill materials should be approved by the geotechnical engineer prior to use or importing to the site. The geotechnical engineer should be notified at least 72 hours before fill is imported to the site to sample and test the material. No imported material should be delivered to the site without proper sampling and testing.

Every other lift of compacted engineered fill should be tested by a representative of the geotechnical engineer prior to placement of subsequent lifts. Continuous observation by the geotechnical engineer of record or a designated representative should be maintained during site prepara tion and compaction of all fill material.

NON-STRUCTURAL FILL

Proposed Tracker Mounted Array Rosebud IHS Hospital

Rosebud, South Dakota

Non-structural fill above the footing elevation and outside structures should be free of organic or other deleterious material, and have a maximum particle size less than 3 inches in any direction. The on-site soils appear suitable for use as non-structural fill. However, all fill materials should be approved by the geotechnical engineer prior to use or importing to the site.

After construction has been completed, fill placement around the outside of the structures and footings should begin promptly. The fill shall be placed in layers and compacted by means of suitable equipment, or by tamping with mechanical tampers. The first layer of fill material should be placed in a relatively uniform horizontal lift. For cohesive fill, compaction should be to 90 percent of Standard Proctor as determined by ASTM D 698 at a moisture content between -3 and +3 percent of the optimum moisture. For non-cohesive fill, compaction should be at a relative density between 60 and 90 percent as determined by ASTM D 4253 and D 4254 at over 95 percent saturation. Every other lift of compacted engineered fill should be tested by a representative of the geotechnical engineer prior to placement of subsequent lifts. Continuous observation by the geotechnical engineer of record or a designated representative should be maintained during site preparation and compaction of all fill material.

EXCAVATIONS

Temporary slopes and excavations should conform to Occupational Safety and Health Administration (OSHA) Standards for the Construction Industry (Construction Standards for Excavations, 29 CFR Part 1026, Subpart P). This document was issued to better insure the safety of workmen entering trenches or excavations. It is mandated by this federal regulation that excavations for utility trenches, basement or footing excavations be constructed in accordance with the new OSHA guidelines.

The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations as required to maintain stability of both the excavation sides and bottom. The contractor's "responsible person", as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations.

UTILITY TRENCHING

Excavation for utility trenches shall be performed in accordance with OSHA regulations as stated in 29 CFR Part 1926. It should be noted that utility trench excavations have the potential to degrade the properties of the adjacent fill materials. Utility trench walls that are allowed to move laterally can lead to reduced bearing capacity and increased settlement of adjacent structural elements and overlying slabs.

Rosebud, South Dakota

Trenches should be excavated so that pipes and culverts can be laid straight at uniform grade between the terminal elevations. Trench width should provide adequate working space and sidewall clearances.

Backfill for utility trenches should be placed to meet the project specifications for the controlled fill of this project. Unless otherwise specified, the backfill for utility trenches may be backfilled with on-site soils. Bedding material should be graded to provide a continuous support beneath all points of the pipe and joints. The soils should be placed in 4 to 6 inch loose lifts and compacted to between 70 and 90 percent relative density as determined by ASTM D 4253 and ASTM D 4254 for non-cohesive soil, or to at least 95 percent of the maximum dry density achieved by the Standard Proctor test at a moisture content between -2 and + 3 percent of the optimum moisture for cohesive soil. Up to 4 inches of bedding material placed directly under the pipes or conduits placed in the utility trench can be compacted to the 90 percent compaction criteria with respect to the Standard Proctor. Compaction testing should be performed for every 200 cubic yards of backfill placed or each lift every 150 linear feet of trench, whichever is less. Backfill of utility trenches should not be performed with water standing in the trench.

SEISMIC DESIGN CONSIDERATIONS

The 2003 International Building Code requires a site class for the calculation of earthquake design forces. This class is a function of soil type (i.e., depth of soil and strata types) based on the anticipated bedrock depth and the estimated shear strength of the upper 100 feet of the soils underlying the site, Site Class "D" is recommended for this project.

DRAINAGE

Water should not be allowed to collect in the foundation excavation, on floor slab areas, or on prepared sub grades of the construction area either during or after construction. Undercut or excavated areas should be sloped toward one comer to facilitate removal of collected rainwater, groundwater, or surface runoff. Infiltration of water into excavations, ponding of water on finished subgrade, or softening or damaging of the bearing materials due to rain or water accumulation should be prevented. Berms or channels may be utilized in the site to prevent flooding of the site during construction. Positive site drainage should be provided to reduce infiltration of surface water around the perimeter of the foundations. The grades should be sloped away from the foundations and surface drainage should be collected and discharged such that water is not permitted to infiltrate the backfill areas.

Rosebud, South Dakota

CONSTRUCTION DETAILS

This report is presented in broad terms to provide data for the purpose of the helical pier contractor to design the helical pile foundation system for the Tracker Mounted PV Array Solar System. Any changes in the design or location of the proposed structures should be assumed to invalidate the conclusions and recommendations given in this report until Twin Rivers Testing has had the opportunity to review the changes and, if necessary, modify our conclusions and recommendations accordingly. It is recommended that the geotechnical engineer be afforded the opportunity of a general review of the final design plans and specifications prior to construction in order to determine if they are consistent with the conclusions and recommendations given in this report. Particular details of foundation design, construction specifications or quality control may develop, and we would be pleased to respond to the questions that you may have regarding these details.

APPENDIX

I

KEYS TO SYMBOLS

BORING LOGS

BORING LOCATION MAP

r7il

TWIN RIVERS TESTING AND

ENVIRONMENTAL, LLC.

N (SPT)

ss

LSS

SRS

LRS

SH

Sack (SK) or Bag

:s:LWL

Cave Depth

RQD

LOGS OF EXPLORATIONS

EXPLANATION OF ABBREVIATIONS AND DESCRIPTIVE TERMS

- Standard "N" penetration resistance test - results recorded as the number of blows of a 140-pound hammer falling 30 inches required to drive a 2-inch O.D. split sample spoon the second and third 6-inch increments of an 18-inch distance.

- Split sample spoon 2-inch O.D. for performing standard penetration resistance tests.

- Modified penetration test - results recorded as the number of blows of a 140-pound hammer falling 30 inches required to drive a 2.5-inch O.D. split spoon the second and third 6-inch increments ofan 18-inch distance.

- Split barrel ring sampler 2-inches I.D. for taking undisturbed samples.

- Split barrel ring sampler 2.5 inches I.D. for taking undisturbed samples.

- Shelby tube sampler for taking undisturbed samples (2" to 3-5/16" I.D.).

- Sample of disturbed soil placed in canvas sack or plastic bag.

- Groundwater level at time of drilling on the date shown on the logs.

- Depth material caves in hole after removal of drilling equipment.

- Rock quality designation (RQD) for the bedrock samples are determined for each core run by summing the length of all sound, hard pieces of core over four inches in length, and dividing this number by the total length of the core run. This value, along with the core recovery percentage, is recorded on the drill logs.

GRAIN SIZES

U.S. Standard Series Sieve Clear Square Sieve Openings

200 40 10 4 ¾" 3" 12"

Silts & Clays SAND GRAVEL Distinguished

Cobbles Boulders on Basis of Fine Medium Coarse Fine Coarse Plasticity

CONSISTENCY RELATIVE DENSITY

Clays & Silts

N (SPT*)

Sands & Gravels

N (SPT*)

Blows/foot Blows/foot

Very Soft 0-2 Very Loose 0-4

Soft 3-4 Firm 5-8

Loose 5-10 Medium Dense 11-30

Stiff 9 -15 Dense 31 -50

Very Stiff 15 -30 Very dense Over 50

Hard Over 30

*Standard Penetration Test; PL= Plastic Limit; LL= Liquid Limit

LOG OF BOREHOLE NO. BH1

Sheet 1 of 1 Project No. 2014--154

CLIENT ARCHITECT/ENGINEER

SITE PROJECT

Rosebud, SO Indian Health Services

REMARKS;

SAMPLES TESTS

a --- ii:' c C) J: w -:f!. !:: ,O! p () 0:: !L,. ~ t: II) [ 2 t.., Cl) DRILL METHOD: 0 w z z~ ::!: ca. C z ~ ...I w •W I- en ~ :J w~

..c:: 0 0 0::

(.) ~ Wo er: ffi z :::i z:r. CJ ~ ~ <D:::::, (J -f- (ll l: u5...J ~(.) w LL C!) ~ 0 u ::

DESCRIPTION OF STRATUM r w

~~o a:::w Wt- 0 0 j:::: Zz ·c <( w Q. li: a. 00:: 1-Z 5 Cl) Ow .,, 0. 0:: ~ >- ~8

>-u. 0 ~ Ua: 8 ei ::!:

w t- ...I •o i~ 0:: (.) Zt- 0 Surface Elev.: 96.8 Feet C) 0 rn z 0:: OQ. ::::i Q. ::,Cl) ~ 0 u

.!LS TOPSOIL ""'., ►' ~~-- .'I .

SANDY LEAN CLAY, DARK BROWN, 1 • ~ 5S

3-5 18/18 13 64 MOIST, STIFF (CL) - 4

2· N"'9 100%

3-

4.0 92.8 ~

,.... - - CLAYEY SAND, FINE GRAINED, LIGHT

4 ~

BROWN. DRY, STIFF (SC) sj St• ss 7--8 18/15 5 ~l 3 83%

~ N=11

8· ... 8'5 POORLY GRADED SAND with CLAY, FINE - - 88•3 ~✓-

-: :-.: ~ • 9 ~ ss 7-12 18/16 5 8 10.0 GRAINED, LIGHT BROWN, DRY, MEDIUM 86.8 ~-- ~ 10

12 89% - - 7 DENSE (§P-S(J _____________ .J - - -

N=24

CLAYEY SAND, FINE GRAINED, CALCIUM 11

STRINGERS, MOIST, MEDIUM DENSE (SC) 0 12 j

~ 13:i°_

~ 14:1 ~ ss 12-13 18/12 13 15.0 81 .8 ' 15

END OF BORING 15 N=29 67%

i-1 f--q l!)

w ...

w C> a_

S:

G

CJ

Ill w "' 0

IX

:}, WATER LEVEL OBSERVATIONS Twin Rinrs STARTED 8127/14 FINISHED 8/27/14

5l. Testing & Environmental 0 WL DRILL CO. Twin Rivers DRILL RIG Simco N 602 E Walker Rd - Cave - North Platte, NE 69 IO I DRILLER DD ASS'T DRILLER MN 8 Depth

0 Telephone: 308-534-5 13 I LOGGED BY MN APPROVED uJ Fax: 308-534-12:26 C) n.

Cl C w V>

:.,,P.~oj~ct ·No. :i

CLIENT

$!TE

Rosebud,SD

REM.ARKS:

DRILL METHOD:

DESCRIPTION OF STRATUM

ce Elev.: 90.6 Feet

Y LEAN CLAY, DA K BROWN, STIFF

(CL)

3.L ·---------------------- 87.1

CLAYEY SAND, FINE GRAINED, LIGHT

BROWN TO TAN. MOIST, CALCIUM

STRINGERS, LOOSE TO DENSE (SC)

8.L ·---------------------- 02.1 POORLY GRADED SAND with CLAY, FINE

10.0 GRAINED, LIGHT BROWN, VERY MOIST,

- 7 DENSE (§P-SG} _____________ .J

CLAYEY SAND, FINE GRAINED, LIGHT

BROWN TO TAN, MOIST, CALCIUM

STRINGERS, MEDIUM DENSE (SC)

15,0

END OF BORING

PROJECT

Indian Health Services

SAMPLES

3-4

N=9

2·2

N""4

7-14

N"44

10·8

N"Z1

18/18 100%

18/18 10 100%

18/18 14 100%

18/18 14 100%

6 !::

ti) ;; z ..J w Cl 0

5 >- u.. a::o a Clo.. :J

TESTS

I- iL:' ~ en ~ a0.

:J UJ~ .c z:r 0 -f- "' ... ~ ~ ~ . Zz en Ow 0 ~ Uo::: 0 Zf-a.. :>ti) ":I c ~ !!l

!!., en C z !.:'.

() Q a:: u ~ t:; u 2 <( w 0. tll ::I! 0:: e, 0 0 (..)

~:1------------i---------....i----....i-----.-....i------------------------ :i, WATER LEVEL OBSERVATIONS

D WL

N.l----+-----------1

- Cave g Depth _,;l-"-.;.:;.;..-+-----------1

Twin Rivers Testing & Environmental

602 E Walker Rd North Platte, NE 69101

Telephone: 308-534-5131

STARTED 8/27/14 FINISHED 8/27114

DRILL CO. Twin Rivers DRILL RIG Simco

DRILLER DD ASST DRILLER MN

~'-----------------------'"""""""----.............. ----.... -----...i..-------' Fax: 308-534-1226 LOGGED BY MN APPROVED

APPENDIX

II

DEFINITIONS

DEFINITIONS

AGGREGATE

AGGREGATE BASE COURSE

ALLOW ABLE BEARING PRESSURE

BACKFILL

BASE COURSE GRADE

BENCH

COMPACTION

CONCRETE SLAB-ON-GRADE

CONSOLIDATION

CONTROLLED FILL

CRUSHED AGGREGATE BASE

COURSE

DIFFERENTIAL SETTLEMENT

EXISTING FILL

EXISTING GRADE

FILL

FINE AGGREGATE BASE COURSE

FINISHED GRADE

LOESS

NATIVE SOIL

OUTCROP

OVERBURDEN

PERCHED GROUNDWATER

Mineral material such as sand, gravel or combinations thereof.

A layer of specified aggregate placed on a subgrade or subbase.

Aggregate is typically a specified open-graded gradation with small amount of rock fines.

The recommended maximum contact stress developed at the interface of the foundation element and the supporting material.

A specified material placed and compacted in a confined area.

Top of base course.

A horizontal surface in a sloped deposit.

Mechanical densification of soils causing the expulsion of air from the void spaces.

A concrete surface layer cast directly on a base, subbase or subgrade.

The reduction of the void ratio of a soil mass due to its own weight or superimposed loads. The time rate of consolidation is dependent on the permeability of the soil and the rate of loading.

Specified material placed and compacted to specified density and/or moisture conditions under observation of a representative or a soil engineer.

A layer of aggregate with crushed, interlocking rock fines or crusher run road base with rock fines.

Unequal settlement between or within foundation elements of a structure.

Materials deposited . through the action of man prior to exploration of the site.

The ground surface at the time of field exploration.

Materials deposited by the action of man.

A layer of specified aggregate placed over course aggregate base to reduce subbase friction.

The final grade created as a part of the project.

Geological deposit of relatively uniform, primarily silt material presumably transported by wind.

The naturally occurring soils on the site.

The exposure of bedrock at the surface of the ground.

Undifferentiated, unconsolidated material directly over a deposit of rock.

Water in a saturated zone underlain by an impervious stratum.

PERCHED GROUNDWATER

PERMEABILITY

PUMPING

ROCK

SCARIFY

SELECT FILL

SETTLEMENT

SLAB ON GRADE

SOIL

STRIP

SUBBASE

SUBBASE GRADE

SUBGRADE

VAPOR BARRIER

VOID RATIO

WEATHERING

deposit of rock.

Water in a saturated zone underlain by an impervious stratum.

The capacity of a material to transmit a fluid.

Phenomenon where the soil surface undulates under transient loads due to the applied stress being carried by the fluids in the voids in the soil mass. Severe cases result in rupture of the soil surface.

A natural agglomerate of mineral grains connected by strong and permanent cohesive forces. Usually requires drilling, wedging, blasting or other methods of extraordinary force for excavation.

To mechanically loosen soil or break down existing soil structure.

Controlled fill material that is classified as low-plasticity and has a liquid limit less than 45 and a plasticity index between 10 and 25.

Downward movement.

Plain, reinforced, or prestressed concrete that is continuously supported by ground and imparts less than 50 percent of the allowable bearing capacity.

Any unconsolidated material composed of discrete solid particles, derived from the physical and/or chemical disintegration of vegetable or mineral matter, which can be separated by gentle mechanical means such as agitation in water.

To remove from present location.

A layer of specified material placed to form a layer between the subgrade and base course.

Top of subbase.

Prepared soil surface.

Polyethylene sheeting (typical) placed as a layer below concrete slab on grade to prevent upward migration of moisture.

The ratio of the volume of voids to the volume of solid particles in a soil mass.

The physical and chemical disintegration and decomposition of rocks and minerals.