Geotechnical Report - EPWater

Geotechnical ReportProposed 1.25 MG Water TankWestway, El Paso County, Texas

Project # 1837192050

Prepared for:

Molzen Corbin6006 North Mesa, Suite 214, El Paso, Texas 79902 March 19, 2019

March 19, 2019

Proposed 1.25 MG Water Tank, Westway, Texas

TABLE OF CONTENTS

REPORT Page

Introduction ............................................................................................................................................................................................1

Proposed Construction.......................................................................................................................................................................1

Soil Study .................................................................................................................................................................................................1

Site Conditions and Geotechnical Profile....................................................................................................................................2

Discussion and Recommendations................................................................................................................................................3

APPENDIX ATest Drilling Equipment and Procedures................................................................................................................................A-1

Unified Soil Classification .............................................................................................................................................................A-2

Terminology Used to Describe the RelativeDensity, Consistency or Firmness of Soil ................................................................................................................................A-3

Soil Moisture Classification ..........................................................................................................................................................A-4

Site Plan ...............................................................................................................................................................................................A-5

Logs of Test Borings .......................................................................................................................................................................A-6

APPENDIX BClassification Test Data.................................................................................................................................................................. B-1

APPENDIX CSpecifications for Earthwork ........................................................................................................................................................ C-1

March 19, 2019


Wood Project No 1937192005 Page 1 of 7

1.0 INTRODUCTION

This report is submitted pursuant to a geotechnical engineering study made by this firm for the proposed groundstorage water tank east of Westway, Texas. The objective of this study was to evaluate the physical properties of thesoils underlying the site to provide recommendations for foundation design, slab support and related earthwork.

2.0 PROPOSED CONSTRUCTION

Details of the project were provided to Wood by Mr. Jerry Paz, P.E. with Molzen-Corbin, Inc.

It is our understanding that the project will consist of the construction of an approximately 1.25 million gallon (MG)ground storage water tank with a height of about 34-feet. The steel tank will be constructed east of the existing 0.3MG tank located on Westway Boulevard, east of Westway, El Paso County, Texas. The proposed tank will beconstructed on a concrete ring foundation. Foundation loading conditions are not known but are anticipated to bemoderate.

Although no grading plan was provided to Wood, it is anticipated that some cut will be required to achieve finalgrades.

Should final design details vary significantly from those outlined above, this firm should be notified for review andpossible modification of recommendations.

3.0 SOIL STUDY

3.1 SUBSURFACE EXPLORATION

Our field exploration program consisted of performing a total of three (3) auger borings with standard penetrationtesting (SPT). Three borings were drilled to depths ranging from 8 to 13 feet below existing grades. (Figure 1). Augerrefusal on dense and cemented soils prevented further advancement of the borings to their planned depth of 30feet.

The test borings were completed using a CME 75 truck-mounted drill rig equipped with 3¼ inch I.D. hollow stemaugers. The borings were conducted in accordance with methodology consistent with ASTM International StandardD1586, Standard Test Method for Penetration Test and Split-Barrel Sampling of Soils. Standard penetration testingwas completed at selected intervals in the borings. During the field study, the soils encountered were examined,visually classified and logged. The locations of the borings are graphically depicted on the Boring Location Plan asshown in Appendix A; they were located by measuring wheel from existing site features and should be consideredaccurate only to the extent implied by the limitation of the depiction. Results of the field study are presented inAppendix A, which includes a brief description of drilling and sampling equipment and procedures, boring locationplan and logs of the test borings

The boring logs and related information included in this report are indicators of subsurface conditions only at thespecific locations and times noted. subsurface conditions, including groundwater levels, at other locations on thesubject site may differ significantly from conditions, which exist at the sampling locations.

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Wood Project No: 1837192050 Page 2 of 5

3.2 LABORATORY ANALYSIS

To aid in soil classification and evaluate the engineering properties of the soil, selected soil samples were tested formoisture content, Atterberg limits and particle size distribution. Laboratory tests were performed in generalaccordance with test standards ASTM D2216, ASTM D4318 and ASTM D6913. The results of the moisture testing,Atterberg Limits and Material Finer than No. 200 (75-μm) Sieve are shown on the boring logs presented in AppendixA. Particle distribution test results are presented in Appendix B.

The soil encountered during the field study was classified in general accordance with the Unified Soil ClassificationSystem. The soil classification symbols appear on the boring logs and are briefly described in Appendix A.

4.0 SITE CONDITIONS & GEOTECHNICAL PROFILE

4.1 SITE CONDITIONS

The proposed tank location is located within an undeveloped tract of land east of an existing water storage tankand Westway, Texas. The topography of the site slopes to the west and south west following regional drainagepatterns. Vegetation on the site generally consists of a sparse to moderate growth of small brush, grass, weeds andother desert flora.

4.2 GEOTECHNICAL PROFILE

The general subsurface conditions encountered during the field exploration conducted February 21, 2019, are shownon the soil boring logs presented in Appendix A. The lines of stratification shown on the logs are based uponexamination of the recovered soil samples and interpretation of the field boring logs and represent the approximateboundaries between the soil types; the actual transitions may be gradual

As the exploratory borings indicate, the soils encountered at the project site generally consist of a dense to verydense and coarse gravelly silty sand with some cobbles that extend from the ground surface to the total depthsexplored (13 feet). In addition, a moderate to strong calcareous cementation is present within the soil profile.Although not observed, boulders may also be encountered during site excavations. It is important to note, standardpenetration test (SPT) sampling methods utilized in auger borings may not accurately depict the grain sizedistribution of coarse samples. SPT samples tend to display a greater percentage of finer material when samplingcoarse materials, such as gravels and cobbles.

The soil classification symbols shown above and elsewhere herein are derived from ASTM D2487, StandardClassification of Soils for Engineering Purposes (Unified Soil Classification System) and D2488, Standard Practice forDescription and Identification of Soils (Visual-Manual Procedure). The descriptions for relative density and firmnessare based on grain size and standard penetration tests as detailed in “Terminology Used to Describe the RelativeDensity, Consistency or Firmness of Soil” in Appendix A of this report.

4.3 SOIL MOISTURE AND GROUNDWATER CONDITION

At the time of our field study, groundwater was not encountered, or should it be expected to occur naturally at thislocale at an elevation that would impact the planned construction. Soil moisture contents were generally dry withvalues less than 1 percent.

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5.0 DISCUSSION & RECOMMENDATIONS

5.1 ANALYSIS OF RESULTS

Based on the results of our field and laboratory study, the soils underlying the project site will provide reliablesupport for the proposed tank following minor soil improvements. The tank proposed structure can be safelysupported on a conventional shallow foundation system bearing on improved native soils or structural fill, providedthe guidelines concerning site preparation and moisture protection presented in Section 5.3 are completed.

It should be noted that a degree of risk is involved with the use of shallow foundations. Should a broken water lineor other source of moisture occur, some movement of foundation and slab is possible.

5.2 GROUND STORAGE TANKS – SHALLOW RING WALL FOUNDATION

It is our understanding that some cut will be required to achieve final grades for the proposed tank. Following sitegrading activities, the recommended soil improvements consists of scarifying the native soils below all foundationelements to a depth of 8 inches. Any oversize materials greater than 3-inches should be removed and the scarifiedsoils should be brought to within plus or minus 2 percent of the optimum moisture content and compacted.Structural fill should then be placed, as required, in compacted lifts to final grade. Compaction of the native soilsand structural fill should be accomplished by mechanical means to obtain a density of not less than 95 percent ofmaximum dry density. Optimum moisture content and maximum dry density should be determined in accordancewith ASTM D 1557.

Below the tank base, it is recommended a minimum thickness of 6 inches of tank bedding be placed. The beddingmaterial should conform to API 650 requirements regarding corrosion protection. In addition, the material shouldbe relatively uniform in gradation, having a maximum particle size of 1 inch and no more than 5 percent by weightpassing the No. 200 sieve. In addition, the perimeter of the steel tank should be supported by continuous concretefooting having a minimum width of 18 inches. The ring wall foundations should enclose the granular material whichlies directly beneath the tank floor.

The perimeter of the steel tank should be supported by a continuous concrete footing having a minimum width of18 inches. The footing should support the steel sides and roof of the tank and the edges of the steel plate comprisingthe bottom of the tank. The ring wall foundation should enclose the granular material which lies directly beneaththe tank floor.

A net allowable soil bearing pressure of 3,500 pounds per square foot is recommended for the design of the ring-wall foundation bearing on improved native soils or structural fill. This bearing pressure applies to full dead plusrealistic live loads and can be safely increased by one-third for temporary loads including wind or seismic forces.The footing should be properly designed with circumferential reinforcement. It is recommended that the footing beembedded a minimum of 2 feet below the lowest adjacent finished grade.

It is estimated that vertical movements of the ring-wall foundation designed as recommended above will not exceed¾ of an inch for moisture contents of the native soils encountered during test drilling or compaction moisturecontents introduced during construction. Differential movements are expected to be less than 75 percent of thetotal movement. Significant moisture increases above these values could result in additional movements. As a result,

March 19, 2019



site drainage and moisture protection recommendations as outlined in Section 5.3 will be critical for the properperformance of the structure.

5.3 SITE DRAINAGE AND MOISTURE PROTECTION

Moisture increases in the soils supporting foundations and slabs would reduce their support value and increasemovements. Therefore, positive site drainage should be provided during construction and carefully maintained forthe life of the structure.

Where slabs or pavements do not immediately adjoin the tank structure, the ground surface should be sloped awayfrom the perimeter in a manner to allow flow along the drainage lines at a minimum grade of 5 percent to pointsat least 15 feet away. Positive drainage should be provided from these points to streets or natural water courses.Long-term ponding of water should never be allowed around the perimeter of the planned tank structure. It isrecommended that any ponding areas be located at least 20 feet from the structure.

5.4 LATERAL LOADS

The pressure exerted on retaining walls will depend on their degree of restraint. Rigid, absolutely restrained wallswith horizontal backfill meeting structural fill requirements as presented in Appendix C of the geotechnical report,should be designed using an "at rest" equivalent fluid pressure of 55 pounds per cubic foot (pcf). Walls allowed torotate around their bases at a distance of 0.001 times their height or more, at the top, should be designed using an"active" equivalent fluid pressure of 35 pcf. Passive pressures for properly compacted structural fill or native soilagainst footings and stem walls should be computed using an equivalent fluid pressure of 375 pcf. An allowablecoefficient of friction of 0.35 may be used in calculations for sliding purposes between the base of the footing andsoil.

The equivalent fluid pressures do not include any lateral component due to either hydrostatic or surcharge loads.The retaining walls at this site should be designed with a drainage system to prevent the build-up of hydrostaticforces behind the wall. If a drain system is not provided, then an additional 62.4 pcf must be added to the lateralforces acting on the wall. Special care should be taken not to over compact the backfill material to reduce thepotential for the build-up of residual compaction pressures against the retaining walls.

The equivalent fluid pressures provided above do not include a factor of safety, however, we recommend that aminimum factor of safety of 1.5 be used for the design of retaining walls against overturning and sliding. Surchargeloads, such as vehicular wheel loads, to the area adjacent to the retaining wall can add additional horizontalcomponents of lateral earth pressures to this wall. The magnitude of these components will depend on the loadsand locations of these loads relative to the retaining wall.

5.5 EXCAVATION CONDITIONS AND SLOPES

Based on the results of the field study, excavations at the project site are anticipated to be difficult due to the coarseand cemented nature of the soils. Past excavation efforts in the general area have been achieved with moderate toheavy earthwork equipment capable of performing some ripping. Earthwork equipment should therefore beadequately sized to excavate and break down the materials encountered on the site. It is the responsibility of thecontractor to verify whether his earthwork equipment is adequate to perform the excavation and grading at the site.

March 19, 2019



Based upon the results of our study, the soils encountered along the majority of the alignment classify as OSHAType C soils. Temporary excavations in Type C soils should be no steeper than 1.5 to 1 (horizontal to vertical) to adepth of 20 feet. Should the excavations remain open for periods longer than 72 hours, maximum slopes shouldnot exceed 2H:1V. Trench excavations greater than 20 feet in depth will require a special design or approval from aregistered engineer.

It is recommended that final slopes for the project, cut or fill, not exceed 3H:1V. Steeper slopes may be provided,but should include erosion control measures that may include rock or concrete rip rap or other approved methods.

The above recommendations for temporary excavation slopes are based on geotechnical considerations only. Theserecommendations do not consider requirements that might be imposed by OSHA, the State of Texas, or othergovernmental agencies. OSHA and other governing entities' regulations should be followed in the process ofplanning for all open excavations and trenches.

6.0 CONSTRUCTION OBSERVATION & TESTING

Recommendations presented in previous sections of this report are predicated on there being continuousobservation and testing by the geotechnical engineer during earthwork operations. Verification of recommendedexcavation, site grading, and required degree of compaction should be performed in accordance with "GuideSpecifications for Earthwork” in Appendix C.

The recommendations presented in this report are based upon a limited number of subsurface samples obtainedfrom three sampling locations at the site. The samples may not fully indicate the nature and extent of the variationsthat actually exist between sampling locations. For that reason, among others, we recommend that Wood beretained to observe earthwork construction. It should be noted if variations or other latent conditions becomeevident during earthwork construction, it will be necessary for us to review these conditions and modify itsrecommendations.

APPENDIX A

TEST DRILLING EQUIPMENT & PROCEDURES

SAMPLING PROCEDURES - Dynamically driven tube samples are usually obtained at selectedintervals in the borings by the ASTM D-1586 procedures. In most cases, 2" O.D.samplers are usedto obtain the standard penetration resistance. Undisturbed samples of firmer soil are often obtainedwith 3" O.D. samplers lined with 2.42" I.D. brass rings. The driving energy is generally recorded asthe number of blows of a 140 pound, 30-inch free fall drop hammer required to advance thesamplers in 6-inch increments. However, in stratified soil, driving resistance is sometimes recordedin 2 or 3-inch increments so that soil changes and the presence of scattered gravel or cementedlayers can be readily detected and the realistic penetration values obtained for consideration indesign. These values are expressed in blows per foot on the logs. Undisturbed sampling of softersoil is sometimes performed with thin walled Shelby tubes (ASTM D-1587). Where samples of rockare required, they are obtained in NX diamond core drilling (ASTM D-2113). Tube samples arelabeled and placed in watertight containers to maintain field moisture contents for testing. Whennecessary for testing, larger bulk samples are taken from auger cuttings.

CONTINUOUS PENETRATION TESTS - Continuous penetration tests are performed by driving a 2"O.D. blunt nosed penetrometer adjacent to or in the bottom of borings. The penetrometer isattached to 1-inch O.D. drill rods to provide clearance to minimize side friction so that penetrationvalues are recorded as the number of blows of a 140 pound, 30-inch free fall drop hammer requiredto advance the penetrometer in one foot increments or less.

BORING RECORDS - Drilling operations are directed by our field engineer or geologist whoexamines soil recovery and prepares boring logs. Soil is visually classified in accordance with theUnified Soil Classification System (ASTM D-2487), with appropriate group symbols being shown onthe logs.

TERMINOLOGY USED TO DESCRIBE THE RELATIVE DENSITYCONSISTENCY, OR FIRMNESS OF SOIL

The terminology used on the boring logs to describe the relative density, consistency or firmness ofsoil relative to the standard penetration resistance is presented below. The standard penetrationresistance (N) in blow per foot is obtained by ASTM D-1586 procedure using 2" O.D., 1-inch I.D.samplers.

RELATIVE DENSITY: Terms for description of relative density of cohesionless,uncemented sand and sand-gravel mixtures.

N

0-45-10

11-3031-5050+

RELATIVE DENSITY

Very LooseLoose

Medium DenseDense

Very Dense

RELATIVE CONSISTENCY: Terms for the description of clay which is saturated or nearsaturation.

N

0-2

2-4

4-8

8-15

15-30

>30

RELATIVE CONSISTENCY

Very Soft

Soft

Firm

Stiff

Very Stiff

Hard

REMARKS

Easily penetrated several inches with fist.

Easily penetrated several inches withthumb.

Can be penetrated several inches withthumb moderate effort.

Readily indented with thumb butpenetrated only with great effort.

Readily indented with thumbnail.

Indented only with difficulty by thumbnail.

RELATIVE FIRMNESS: Terms for the descriptions of partially saturated and/or cementedsoil which commonly occurs in the Southwest including clay, cemented granular materials,silt and silty and clayey granular soil:

N

0-45-8

9-1516-3031-5050+

RELATIVE DENSITY

Very SoftSoft

Moderately FirmFirm

Very FirmHard

SOIL MOISTURE CLASSIFICATION

MOISTURECONDITION

FIELDIDENTIFICATION

ESTIMATED RANGE OFMOISTURE

Group A(%)

Group B(%)

Dry Absence of moisture, dusty. Dry to the touch. 0-4 0-8

Damp Grains appear slightly darkened, but no visiblewater. Silt/clay may clump. Sand will not bulk.

Soils are below plastic limits.

4-8 8-16

Moist Grains appear darkened, but no visible water.Silt/clay will clump. Sand will bulk. Soils are

often at or near plastic limits.

8-16 16-30

Wet Visible water on larger grain surfaces. Sandand cohesionless silt exhibit dilatancy.

Cohesive silt/clay can be readily remolded.“Wet” indicates that the soil is much wetter than

the optimum moisture content and above theplastic limit (APL).

>16 >30

Water Bearing A water-producing formation. N/A N/A

Group A - Coarse Grained Soils, nonplastic to plasticity index <7.Includes: SM, SP-SM, SP, SW, GM, GP, and GW.

Group B - Fine Grained Soils to clayey sands & gravels with a plasticity index >7.Includes: GC, SC, ML, MH, CL, and CH.

FIGURE NO.1

CLIENT: Molzen-Corbin, Inc.1155 Commerce Drive, Suite FLas Cruces, NM 88011

LEGEND:

PROJECT NO.

1837192050

Boring Approximate Location

PROJECT:

Geotechnical StudyProposed 1.25 MG Water Tank

Westway BoulevardWestway, El Paso County, Texas

REV NO.0

DATE3/14/2019

E & I S, INC.125 MONTOYA ROADEL PASO, TX 39932

DRAWN BY:

MJBCHK’D BY:

DAV

SCALE:

AS SHOWN

PROJECTION:

BORING LOCATION PLAN

1

1

13.5

11.1

8-7-12

20-46-35

25-50(5")

21-32-50(2")

33-50(1")

S

S

S

S

S

SILTY SAND, some gravel and cobbles,nonplastic, brown to dark brown, dry.

Strong Calcareous Cementation at 2 feet.

GRAVELLY SILTY SAND, some cobbles,nonplastic, brown, dry.

Auger Refused at 10'Sampler Refused at 10.5833'

19

81

SM

GM

DATE

PROJECT

DATUM

See Site Plan

CME 75Hollow Stem Auger

Sam

ple

Type

Sam

ple

JOB NO. 1837192050

Westway, TexasProposed 1.25 MG Ground Storage Water Tank

RIG TYPEBORING TYPE

None

1

REMARKSGra

phic

alLo

gSURFACE ELEV. Existing

0

5

10

15

20

25

30DEPTH(ft)

A - Drill cuttingsS - 2" O.D. 1.375" I.D. Split-Barrel SamplerU - 3" O.D. 2.375" I.D. Split-Barrel SamplerSH - 3" O.D. Shelby Tube SampleTC - Texas Cone

HOUR DATE SAMPLE TYPE

1

VISUAL CLASSIFICATIONUni

fied

Soil

Clas

sific

atio

nor

Roc

k U

nit

Blow

s Pe

rSi

x In

ches

Dep

thin Fe

et

2/21/19LOCATION

Existing

B-1

Page of

LOG OF TEST BORING NO.GROUNDWATER

Plas

ticity

Inde

x

Plas

tic L

imit

Liqu

id L

imit

Perc

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ines

Moi

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eigh

t

SPT

N-V

alue

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netr

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sist

ance

Environment & Infrastructure Solutions, Inc.125 Montoya RoadEl Paso, TX 79932Telephone: 915-585-2472

1 19.9

5-17-23

25-50(4")

10-50(5")

50(1")

S

S

S

S

GRAVELLY SILTY SAND, some cobbles,nonplastic, brown, dry.

SILTY SAND, some gravel and cobbles,moderate to strong calcareouscementation, nonplastic, brown, dry.

GRAVELLY SILTY SAND, some cobbles,strong calcareous cementation,nonplastic, brown, dry.Auger terninated at 7'-6".Sampler Refused at 7'-7".

40 GM

SM

GM

DATE

PROJECT

DATUM

See Site Plan


Sam

ple

Type

Sam

ple

JOB NO. 1837192050


RIG TYPEBORING TYPE

None

1

REMARKSGra

phic

alLo


0

5

10

15

20

25

30DEPTH(ft)



1


fied

Soil

Clas

sific

atio

nor

Roc

k U

nit

Blow

s Pe

rSi

x In

ches

Dep

thin Fe

et

2/21/19LOCATION

Existing

B-2

Page of


Plas

ticity

Inde

x

Plas

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imit

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SPT

N-V

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ance


1 11.6

4-11-15

18-36-50

17-50(5")

50(5")

50(5")

S

S

S

S

S

GRAVELLY SILTY SAND, some cobbles,moderate to strong calcareouscementation, nonplastic, brown, dry.

Auger Refused at 13'Sampler Refused at 11'

26

86

GM

DATE

PROJECT

DATUM

See Site Plan


Sam

ple

Type

Sam

ple

JOB NO. 1837192050


RIG TYPEBORING TYPE

None

1

REMARKSGra

phic

alLo


0

5

10

15

20

25

30DEPTH(ft)



1


fied

Soil

Clas

sific

atio

nor

Roc

k U

nit

Blow

s Pe

rSi

x In

ches

Dep

thin Fe

et

2/21/19LOCATION

Existing

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Page of


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APPENDIX B

TABULATION OF TEST RESULTS

DATE: March 2019 Wood Project No.: 1837192050_PROJECT: 1.25 MG Water Tank

El Paso County, Texas

NV-No ValueNP-Nonplastic

BORINGNO.

DEPTHUNIFIEDCLASS.

LL PL PISIEVE ANALYSIS - ACCUM. % PASSING MOISTURE

%No.200 No.140 No.100 No.60 No.40 No.20 No.10 No.4 ⅜” ¾” 1” 1½” 2” 3”

B-1 2½’-4’ SM 13.5 15 18 21 24 30 40 55 68 83 89 100 0.8B-1 7½’-9’ GP-GM NV -- NP 11.1 12 14 16 18 22 29 44 63 79 83 100 0.9B-2 5’-6½’ SM NV -- NP 19.9 22 25 28 32 38 47 61 72 84 100 0.9B-3 2½’-4’ GP-GM NV -- NP 11.6 13 16 19 21 26 34 49 63 81 92 100 0.7

APPENDIX C

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Wood Project No. 1837192050 Page 1 of 3

GUIDE SPECIFICATIONS FOR EARTHWORK

1. SCOPE

Includes all clearing and grubbing, removal of obstructions, general excavating, filling and any related itemsnecessary to complete the grading for the entire project in accordance with these specifications.

2. SUBSURFACE SOIL DATA

Subsurface soil studies have been made and the results are available for examination by the contractor. Thecontractor is expected to examine the site and determine for himself the character of materials to beencountered.

No additional allowance will be made for rock removal, site clearing and grading, filling, compaction,disposal or removal of any unclassified materials.

3. CLEARING AND GRUBBING

A. General: Clearing and grubbing will be required for all areas shown on the plans to be excavated oron which fill is to be constructed.

B. Clearing: Clearing shall consist of removal and disposal of the existing vegetation located within theareas to be cleared.

C. Grubbing: Stumps, matted roots and roots larger than 2 inches in diameter shall be removed fromwithin 6 inches of the surface of areas on which fills are to be constructed except in roadways.Materials as described above within 18 inches of finished subgrade in either cut or fill sections shallbe removed. Areas disturbed by grubbing will be filled as specified hereinafter for STRUCTURAL FILL.

4. EARTH EXCAVATION

A. Earth excavation shall consist of the excavation and removal of suitable soil for use as embankmentas well as the satisfactory disposal of all vegetation, debris and deleterious materials encounteredwithin the area to be graded and/or in a borrow area.

B. Excavated areas shall be continuously maintained such that the surface shall be smooth and havesufficient slope to allow water to drain from the surface.

5. SELECT FILL

A. General: Select fill shall consist of a controlled fill constructed in areas indicated on the gradingplans.

B. Materials:

(1)Physical Characteristics: Structural fill material shall consist of soil that conforms to the followingphysical characteristics:

March 19, 2019



Sieve Size Percent Passing(Square Openings) by Weight

3 inch 1003/4 inch 70 - 100No. 4 40 - 100No. 200 5 - 30

The plasticity index of the material, as determined in accordance with ASTM D4318, shall not exceed12. The fill material shall be free from roots, grass, other vegetable matter, clay lumps, rocks largerthan 3 inches in any dimension, or other deleterious materials.

(2) Site Soil: Site soil from cuts may be used for fill provided they meet the requirements inparagraph 5.B(1). The results of this soil study indicate that the majority of the site soils will meet therequirements for structural fill, however some screening of oversize materials will be required.

(3) Borrow: When the quantity of suitable material required for embankments is not available withinthe limits of the jobsite, the contractor shall provide sufficient materials to construct theembankments to the lines, elevations and cross sections as shown on the drawings from borrowareas. The contractor shall obtain from owners of said borrow areas the right to excavate material,shall pay all royalties and other charges involved, and shall pay all expenses in developing the sourceincluding the cost of right-of-way required for hauling the material.

C. Construction:

(1) Subgrade Treatment: The project area shall be inspected by a representative of the geotechnicalengineer prior to fill placement to verify clearing and grubbing.

The recommended site preparation consists of scarifying the native soils below the base of allfoundation elements. Materials exceeding 3-inches in nominal diameter shall be removed and thescarified soils shall then be brought to within plus or minus 2 percent of the optimum moisturecontent and compacted. Structural fill should then be placed, as required, in compacted lifts to finalgrade.

During construction, the project area shall be shaped to provide drainage of surface water in orderto avoid the ponding of water. Surface water shall be pumped immediately from the constructionarea after each rain and a firm subgrade maintained.

(2) Compaction: All fill shall be spread in layers not exceeding 8 inches, moisture conditioned asnecessary, and compacted. Moisture content at the time of compaction shall be within plus or minus2 percent of the optimum moisture content. Compaction of the fill shall be accomplished bymechanical means only to obtain a density of not less than 95 percent of maximum dry density forthe building pad, paved areas, and other structural areas. Embankments outside the building padsshall be compacted to 95 percent of maximum dry density. Optimum moisture content and maximumdry density for each soil type used shall be determined in accordance with ASTM D1557. Wherevibratory compaction equipment is used, it shall be the contractor's responsibility to insure that thevibrations do not damage nearby building or other adjacent property.

March 19, 2019



(3) Weather Limitations: Controlled fill shall not be constructed when the atmospheric temperatureis below 35 degrees F. When the temperature falls below 35 degrees, it shall be the responsibility ofthe contractor to protect all areas of completed surface against any detrimental effects of groundfreezing by methods approved by the geotechnical engineer. Any areas that are damaged by freezingshall be reconditioned, reshaped and compacted by the contractor in conformance with therequirements of this specification without additional cost to the owner.

D. Slope Protection & Drainage: The edges of the controlled fill embankments shall be graded to thecontours shown on the drawings and compacted to the density required in paragraph 5.C.(2). Slopessteeper than 1 vertical to 3 horizontal shall be protected from erosion.

6. INSPECTION & TESTS

A. Field Inspection & Testing: The owner shall employ the services of a registered, licensedgeotechnical engineer for consultation during all controlled earthwork operations. The geotechnicalengineer shall provide continuous on-site observation and testing by experienced personnel duringconstruction of controlled earthwork activities. The contractor shall notify the engineer at least twoworking days in advance of any field operations of the controlled earthwork, or of any resumption ofoperations after stoppages. Tests of fill materials and embankments will be made at the followingsuggested minimum rates:

(1) One field density test in the building area for each 2,000 square feet of original ground surfaceor a minimum of three (3), whichever is greater, prior to placing fill.

(2) One field density test in the building area for each 2,000 square feet of fill placed or each layerof fill for each work area or a minimum of three (3), whichever is the greater number of tests.

(3) One moisture-density curve for each type of material used, as indicated by sieve analysis andplasticity index.

B. Report of Field Density Tests: The geotechnical engineer shall submit, daily, the results of fielddensity tests required by these specifications.

C. Costs of Tests & Inspection: The costs of tests, inspection and engineering, as specified in thissection of the specifications, shall be borne by the owner.

Documents

Geotechnical Report - EPWater