Geotechnical Engineering Report...Our geotechnical engineering scope of work for this project...

REPORT COVER PAGE

Geotechnical Engineering Report__________________________________________________________________________

Proposed San Tan Valley Administration ComplexNorthwest of Bella Vista Road and Sierra Vista Drive

San Tan Valley, ArizonaMarch 26, 2019

Terracon Project No. 65185202

Prepared for:Arrington Watkins Architects, LLC

Phoenix, Arizona

Prepared by:Terracon Consultants, Inc.

Tempe, Arizona

Terracon Consul tants, Inc. 4685 S. Ash Avenue, Ste. H-4 Tempe, AZ 85282P (480) 897 8200 F (480) 897 1133 terracon.com

REPORT COVER LET TER T O SIGN

March 26, 2019

Arrington Watkins Architects, LLC5240 North 16th Street, Suite 101Phoenix, Arizona 85016

Attn: Mr. Michael ConderP: 602-279-4373E: [email protected]

Re: Geotechnical Engineering ReportProposed San Tan Valley Administration ComplexNorthwest of Bella Vista Road and Sierra Vista DriveSan Tan Valley, ArizonaTerracon Project No. 65185202

Dear Mr. Conder:

Terracon Consultants, Inc. (Terracon) has completed the Geotechnical Engineering services forthe above referenced project. This study was performed in general accordance with TerraconProposal No. P65185202 Revision 1 dated September 12, 2018. This report presents the findingsof the subsurface exploration and provides geotechnical recommendations concerning earthworkand the design and construction of foundations, floor slabs and pavements for the proposed project.

Design and construction of a new ¼-mile segment of Schnepf Road roadway is also planned aspart of the proposed project. Geotechnical and pavement field exploration, laboratory testing results,and recommendations for the planned roadway will be provided in a separate report.

We appreciate the opportunity to be of service to you on this project. If you have any questionsconcerning this report or if we may be of further service, please contact us.

Sincerely,Terracon Consultants, Inc.

Eddy F. Ramirez, P.E. Donald R. Clark, P.E.Senior Staff Engineer Senior Principal

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REPORT TOPICS

INTRODUCTION ............................................................................................................. 1PROJECT DESCRIPTION .............................................................................................. 2SITE CONDITIONS ......................................................................................................... 3EXPLORATION AND TESTING PROCEDURES ........................................................... 3GEOTECHNICAL CHARACTERIZATION ...................................................................... 5CORROSIVITY................................................................................................................ 8SEISMIC CONSIDERATIONS ........................................................................................ 9GEOTECHNICAL OVERVIEW ....................................................................................... 9SHALLOW FOUNDATIONS ......................................................................................... 11LATERAL EARTH PRESSURES ................................................................................. 13FLOOR SLABS............................................................................................................. 13PAVEMENTS ................................................................................................................ 15EARTHWORK............................................................................................................... 17GENERAL COMMENTS ............................................................................................... 24

Note: This report was originally delivered in a web-based format. Orange Bold text in the report indicates a referencedsection heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on theGeoReport logo will bring you back to this page. For more interactive features, please view your project online atclient.terracon.com.

ATTACHMENTS

SITE LOCATION AND EXPLORATION PLANSEXPLORATION RESULTS(General Notes, Unified Soil Classification System, Boring Logs, Infiltration TestingResults, and Laboratory Testing Results)

Note: Refer to each individual Attachment for a listing of contents.

http://client.terracon.com/

Geotechnical Engineering ReportProposed San Tan Valley Administration Complex San Tan Valley, ArizonaMarch 26, 2019 Terracon Project No. 65185202

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REPORT SUMMARY

Topic 1 Overview Statement 2

ProjectDescription

Based on the information provided, we understand the proposed development willconsist of two single-story buildings and paved covered parking and drives.Design and construction of a new ¼-mile segment of Schnepf Road roadway is alsoplanned as part of the proposed project. Geotechnical and pavement field exploration,laboratory testing results, and recommendations for the planned roadway will beprovided in a separate report.There will be future expansions of the planned facility; however, those futureexpansions are not included in our scope of work.

GeotechnicalCharacterization

Subsurface conditions on the site generally consist of medium stiff to very stiff sandylean clay and sandy fat clay extending to depths of about 4 to 9 feet below the groundsurface; and generally followed by very stiff to hard sandy lean clay and mediumdense to very dense clayey sand with variable amounts of silt and gravel to the fulldepth of exploration of approximately 26½ feet.Groundwater was not encountered in the borings to a maximum depth of 26½ feet.

ShallowFoundations

Shallow foundations can be utilized for the proposed buildings. Maximum allowable bearing pressure = 2,500 psf with a minimum 18-inch

embedment depth is recommended. Expected settlements: 1 inch or less total, ¾ inch or less differential Shallow foundations should be supported on engineered fill as outlined in

the Earthwork section of the report.

Earthwork

In shallow foundation areas for the proposed project, remove and recompactthe existing soils to a minimum depth of 2 feet below the bottom of footingsor 4 feet below existing site grades, whichever depth is greater. Removalshould extend a minimum of 5 feet beyond the edges of footings.

The on-site near surface clay soils exhibited moderate to high expansionpotentials. Therefore, the upper 24 inches of subgrade soils beneath interiorslab-on-grade floor slabs and aggregate subbase should consist of importedlow volume change materials.

Subgrade soils beneath pavements should be scarified, moistureconditioned and compacted to a minimum depth of 10 inches. Due to theexpansive nature of the clay subgrade soils, the use of lime stabilization ofthe upper 12 inches of subgrade should be considered to reduce the effectof the shrink/swell movements of the expansive subgrade soil. However,some effects of the shrink/swell should still be expected. Reducing and/orremoving the stabilized subgrade soils below the recommended 12 incheswill greatly increase the risk of pavement cracking, grade and drainageimpacts, trip hazards and premature pavement failure due to swellingsubgrade soils. The lime stabilization should be in accordance with Section


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Topic 1 Overview Statement 2

309 of the specifications outlined in the Maricopa Association ofGovernments (1MAG, 2018).

Expansive Soils

Expansive soils are present on this site. This report provides recommendations tohelp mitigate the effects of soil shrinkage and expansion. However, even if theseprocedures are followed, some movement and (at least minor) cracking in thestructure and pavements should be anticipated. The severity of cracking and other(cosmetic) damage such as uneven floor slabs and pavement failures will probablyincrease if any modification of the site results in excessive wetting or drying of theexpansive soils. The report details measures to reduce the potential of distress beingcaused by expansive soil conditions.

Below-GradeStructures No basements are planned.

SeismicConsiderations

Based on the site soil properties, the site is classified as Site Class D in accordancewith Chapter 20 of ASCE 7 as required by the 2012/2015 IBC

Pavements

Based on the anticipated traffic loading outlined in this report and with subgradeprepared as noted in Earthwork, the recommended minimum pavement sectionsfor the project are as follows:Asphalt:

3.0” AC over 4” ABC in Automobile Drives and Parking Areas 3.5” AC over 6” ABC in Main Drives and Light Truck Areas

Concrete: 5.0” PCC over 4” ABC in Automobile Drives and Parking Areas 6.0” PCC over 4” ABC in Main Drives and Light Truck and Trash Enclosure

AreasGeneralComments

This section contains important information about the limitations of this geotechnicalengineering report.

1. If the reader is reviewing this report as a pdf, the topics above can be used to access the appropriate sectionof the report by simply clicking on the topic itself.

2. This summary is for convenience only. It should be used in conjunction with the entire report for designpurposes.

1 Maricopa Association of Governments, 2018 Revision to the 2015 Edition, Uniform Standard Specifications andDetails for Public Works Construction, Arizona.


INTRODUC TION

Geotechnical Engineering ReportProposed San Tan Valley Administration Complex

Northwest of Bella Vista Road and Sierra Vista DriveSan Tan Valley, ArizonaTerracon Project No. 65185202

March 26, 2019

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineeringservices performed for the proposed San Tan Valley Administration Complex to be locatedNorthwest of Bella Vista Road and Sierra Vista Drive in San Tan Valley, Arizona. The purpose ofthese services is to provide information and geotechnical engineering recommendations relativeto:

Subsurface soil conditions Seismic site classification per IBC Groundwater conditions Foundation design and construction Floor slab design and construction Lateral earth pressures Pavement design and construction Site preparation and earthwork Excavation considerations

Our geotechnical engineering scope of work for this project included the following:

Fourteen (14) test borings drilled to depths ranging from approximately 5 to 26½ feet inthe proposed building, pavement, and underground corrugated metal pipes areas;

Two (2) double ring infiltration testing in the proposed retention basin areas; Laboratory testing of soil samples; Geotechnical engineering analyses; and, Preparation of this report

Maps showing the site and boring locations are shown in the Site Location and ExplorationPlan sections, respectively. A log of each boring is included in the Exploration Results sectionof this report. The double ring infiltration test results are presented in the Exploration Resultssection. The results of the laboratory testing performed on soil samples obtained from the siteduring the field exploration are included on the boring logs and as separate graphs in theExploration Results section.



PROJECT DESCRIPTION

Item Description

Project Description

Based on the information provided, we understand the proposed developmentwill consist of two single-story buildings and paved covered parking and drives.Design and construction of a new ¼-mile segment of Shnepf Road roadway isalso planned as part of the proposed project. Geotechnical and pavement fieldexploration, laboratory testing results and recommendations for the plannedroadway will be provided in a separate report.There will be future expansions of the planned facility; however, thoseexpansions are not included in our scope of work.

Building Construction

The proposed buildings will consist of metal stud and masonry constructionsuperstructures supported on shallow spread footings. We anticipate that thefloor in each building will be a concrete slab-on-grade. We understand theparking and drive areas will generally consist of asphalt concrete or portlandcement concrete pavements

Maximum Loads Columns: 50 kips Walls: 3 to 5 kips per linear foot (klf) Slabs: 150 pounds per square foot (psf)

Grading/Slopes

The site is relatively flat; therefore, grading operations across the site areanticipated to include relatively minor amounts of cuts and fills on the order ofa maximum of two feet. Excavations for proposed retention basins andunderground storm-water detention corrugated meatal pipes (CMP) areanticipated to be on the order of about 3 and 15 feet below the existing groundsurface, respectively.

Below-GradeStructures No basements are planned.

Retaining Walls None are planned.

Storm-waterRetention

Storm-water retention basins are planned to be located on the southwestcorner of the project site. The depth of the bottom of the retention basin willbe approximately 3 feet below grade.We understand the proposed development at the site may also include 10-foot diameter underground corrugated metal pipes (CMP) for storm-waterdetention. The storm-water retention CMPs are planned to be constructedbeneath proposed paved drive areas.



Item Description

Pavements

On-site drives and parking area pavements for automobile and truck traffic areanticipated to consist of asphalt concrete and portland cement concrete. Thefollowing are the anticipated design equivalent single axle loads (ESALs) forthe on-site pavements:

Automobile Drives & Parking Areas: 7,000 ESALs Main Drives & Light Truck Drive Areas: 27,000 ESALs, and possibly

greater depending on site specific truck traffic informationThe pavement design period is 20 years

SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with thefield exploration.

Item Description

Parcel InformationThe project is located Northeast of Bella Vista Road and Schnepf Road in SanTan Valley, Arizona. See the attached Site Location for additional siteinformation.

ExistingImprovements The site is undeveloped agricultural land.

SurroundingImprovements

North: Undeveloped agricultural land.South: Undeveloped agricultural land followed by East Bella Vista Road.East: Undeveloped agricultural land.West: Undeveloped agricultural land followed by Central Arizona College-San Tan Campus.

Current GroundCover Agricultural land with alfalfa crop.

Existing Topography Relatively flat.

EXPLORATION AND TESTING PROCEDURES

Field Exploration

A total of 14 borings were drilled at the project site on January 31, 2019. The approximate boringlocations are shown on the Exploration Plan, and the location and depth of the borings aresummarized in the following table:



Number of Borings Boring Depth (feet) Planned Location5

(B-1 thru B-8) 15½ to 18½ Proposed Building Areas

2(CMP-1 and CMP-2) 25 and 26½ Proposed Corrugated Metal Pipe

(CMP) Area

4(P-1 thru P-4) 5 Proposed On-site Pavement

Areas

Boring Layout and Elevations: Terracon personnel provided the boring layout based on existingfeatures and a hand-held GPS unit. Coordinates for each boring were obtained with a handheldGPS unit (estimated horizontal accuracy of about ±10 feet). If elevations and a more preciseboring layout are desired, we recommend the borings be surveyed.

Subsurface Exploration Procedures: The borings were advanced with a truck-mounted D-120drill rig utilizing 8-inch outside diameter hollow-stem augers. At selected intervals, samples of thesubsurface materials were taken at borings locations for the proposed buildings and undergroundCMPs by driving split-spoon (SPT) or ring-lined barrel samplers in general accordance with ASTMStandards. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrelsampling spoon is driven into the ground by a 140-pound automatic hammer falling a distance of 30inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPTresistance values, also referred to as N-values, are indicated on the boring logs at the test depths. A3-inch O.D. and 2.5-inch I.D. ring lined sampler was used for sampling in the upper 10 feet in thesoil borings. Ring-lined, split-barrel sampling procedures are similar to standard split spoonsampling procedure; however, blow counts are typically recorded for 6-inch intervals for a total of12 inches of penetration. Bulk samples of subsurface materials were obtained from all the borings.Groundwater was not encountered during drilling and sampling. For safety purposes, all boringswere backfilled with auger cuttings after their completion.

Our exploration team prepared field boring logs as part of the drilling operations. The samplingdepths, penetration distances, and other sampling information were recorded on the field boringlogs. These field logs included visual classifications of the materials encountered during drillingand our interpretation of the subsurface conditions between samples. The samples were placedin appropriate containers and taken to our soil laboratory for testing and classification by ageotechnical engineer. Final boring logs were prepared from the field logs. The final boring logsrepresent the geotechnical engineer's interpretation of the field logs and include modificationsbased on observations and tests of the samples in our laboratory.



Laboratory Testing

Samples retrieved during the field exploration were taken to the laboratory for further observationby the project geotechnical engineer and were classified in accordance with the Unified SoilClassification System (USCS). At that time, the field descriptions were confirmed or modified asnecessary and an applicable laboratory testing program was formulated to determine engineeringproperties of the subsurface materials.

General laboratory tests were conducted on selected soil samples and the test results arepresented in the Exploration Results section of this report. These results were used for thegeotechnical engineering analyses, and the development of foundation recommendations.Laboratory tests were performed in general accordance with the applicable ASTM, local or otheraccepted standards.

Selected soil samples obtained from the site were tested for the following engineering properties:

n Atterberg Limits n Sieve Analysisn Moisture Content n Dry Densityn Consolidation n Moisture Density Relationshipn Remolded Swell n pHn Soluble Sulfate n Minimum Resistivityn Soluble Chloride

GEOTECHNICAL CHARACTERIZATION

Geology

The project area is located in the Basin and Range physiographic province (2Cooley, 1967) of theNorth American Cordillera (3Stern, et al, 1979) of the southwestern United States. The southernportion of the Basin and Range province is situated along the southwestern flank of the ColoradoPlateau and is bounded by the Sierra Nevada Mountains to the west. Formed during middle andlate Tertiary time (100 to 15 million years ago), the Basin and Range province is dominated byfault-controlled topography. These mountain ranges and valleys have evolved from generallycomplex movements and associated erosional and depositional processes.

2 Cooley, M.E., 1967, Arizona Highway Geologic Map, Arizona Geological Society.

3 Stern, C.W., et al, 1979, Geological Evolution of North America, John Wiley & Sons, Santa Barbara, California.



Surficial geologic conditions mapped at the site (4Richard, et al, 2000) consist of Holocene surficialdeposits. This unit is described as unconsolidated deposits associated with modern fluvialsystems. This unit consists primarily of fine-grained, well-sorted sediment on alluvial plains, butalso includes gravelly channel, terrace, and alluvial fan deposits on middle and upper piedmonts.

Subsurface Profile

Specific conditions encountered at each boring location are indicated on the individual boring logspresented in the Exploration Results section of this report. Stratification boundaries on the boringlogs represent the approximate location of changes in soil types; in-situ, the transition betweenmaterials may be gradual. Based on conditions encountered in the borings, subsurface conditionson the project site can be generalized as follows:

DescriptionApproximate

Depth to Bottom ofStratum (feet)

Material Description Consistency / RelativeDensity

Stratum 1 4 to 9 Sandy Lean Clay, Sandy Fat Clay Medium Stiff to VeryStiff

Stratum 2 15 to 19 Clayey Sand with variable amounts ofgravel, Sandy Lean Clay

Very Stiff to Hard /Medium Dense to Very

Dense

Stratum 3 26½ (maximumdepth explored)

Sandy Lean Clay, Silty Clayey Sand,Clayey Sand

Hard /Dense to Very Dense

Laboratory tests were conducted on selected soil samples and the test results are presented inthe Exploration Results section of this report. Test results indicate the near surface clay soilsexhibit medium to high plasticity characteristics.

When water was added to samples of laboratory compacted on-site near surface soils, thecompacted soils exhibited medium to high expansive potential when inundated with water at asurcharge of 100 psf.

In response to wetting of relatively undisturbed samples while supporting typical foundation loads,the near surface and near surface soils exhibited variable low hydro-compaction (collapse)potential at in-situ moisture content and density. These same soils show low compression undertypical foundation pressures.

4 Richard, S. M., Reynolds, S.J., Spencer, J. E., and Pearthree, P. A., 2000, Geologic Map of Arizona: Arizona Geological SurveyMap 35, 1 sheet, scale 1:1,000,000.



Groundwater Conditions

Groundwater was not observed in any of the test borings at the time of our field exploration, norwhen checked upon completion of drilling. These observations represent groundwater conditionsat the time of the field exploration and may not be indicative of other times, or the conditions atother locations. Groundwater conditions can change with varying seasonal and weatherconditions, and other factors.

Based on information obtained from the Arizona Department of Water Resources – GroundwaterData website (https://gisweb.azwater.gov/waterresourcedata/GWSI.aspx), the depth to regionalgroundwater was measured to be approximately 353 feet below the ground surface at an ArizonaDepartment of Water Resources (ADWR) monitored well sites (Local I.D.: D-03-08 23BAA)located approximately 5,900 feet east-southeast of the site.

Infiltration Test Results

Infiltration testing was conducted at the proposed location of the on-site retention basins at thelocations shown on the attached Exploration Plan. The infiltration testing was performed ingeneral accordance with the ASTM D3385 Standard Test Method for Infiltration Rate of Soil inField Using Double-Ring Infiltrometer test method. A backhoe and operator were subcontractedto excavate to a depth of approximately 3 feet below the existing ground surface at the infiltrationtest locations. Detailed test results of field measurements for each of the two double ringinfiltration tests are shown on the attached Exploration Results. The double ring infiltration testfield measurements are provided to aid with the design of the proposed storm-water retentionbasins. We understand the storm-water retention basins design will be performed by others.

The field infiltration rates measured are based on the soil conditions encountered at the particularlocations of the infiltration tests, and the actual infiltration rate may vary from the values reportedhere. The following table summarizes the field measurements of the double ring infiltration testingperformed at the site:

Infiltration Test Results

Test HoleTest Depth

(feet)Visual Soil Classification Inner Ring Field Infiltration

Rate (inches/hour)DR-1 3 Sandy Lean Clay 0.4DR-2 3 Sandy Lean Clay 0.7

It should be noted that siltation and vegetation growth along with other factors may affect theinfiltration rates of the on-site retention basin areas. The infiltration rates presented in this reportare unfactored field measurements, and a de-rating factor should be applied to these infiltrationrates during the design of the proposed storm-water retention basins (performed by others). The

https://gisweb.azwater.gov/waterresourcedata/GWSI.aspx



de-rating factors should be in accordance with the Town of San Tan Valley Standards and thePinal County Drainage Policies and Standards.

We recommend that excavations for the retention basins be excavated with light weightequipment to help reduce compaction of the basin bottom surface which will ultimately be usedfor infiltration of storm water. Once constructed, no traffic should be allowed to travel across thebasin bottom. It should be noted that compaction of the basin bottom will result in reducedinfiltration rates. If compaction of the basin bottom does occur, the exposed surface should bescarified to a minimum depth of 8 inches and left uncompacted.

CORROSIVITY

The following table lists the results of laboratory soluble sulfate, soluble chloride, electricalresistivity, and pH testing. The values may be used to estimate potential corrosive characteristicsof the on-site soils with respect to contact with the various underground materials which will beused for project construction.

Corrosivity Test Results Summary

LocationSampleDepth(feet)

Soil Description pHElectricalResistivity

(Ω-cm)

SolubleSulfateContent(ppm)

SolubleChlorideContent(ppm)

B-1 0 – 4 Sandy Lean Clay 8.4 3,103 224 56

B-8 0 – 4 Sandy Fat Clay 8.3 2,530 452 85

CMP-1 5 – 8 Clayey Sand 8.3 809 1,321 467

CMP-2 5 – 8 Clayey Sand 8.3 968 240 357

Results of soluble sulfate testing indicate that samples of the near surface soils (upper 4 feet)tested generally classify as S0 according to Table 19.3.1.1 of Section 318 of the AmericanConcrete Institute (ACI) Building Code Requirements for Structural Concrete. Concrete should bedesigned in accordance with the provisions of the ACI Building Code Requirements for StructuralConcrete, Section 318, Chapter 19.

Results of soluble sulfate testing indicates that samples of the deeper soils (at a depth between5 and 8 feet) tested classify as S1 according to Table 19.3.1.1 of Section 318 of the AmericanConcrete Institute (ACI) Building Code Requirements for Structural Concrete. This result indicates



a moderately potentially corrosive environment and Type II portland cement should be used inthe concrete mix for concrete on and below grade for this site. Concrete should be designed forExposure Class S1 in accordance with Table 13.3.2.1of the ACI Building Code Requirements forStructural Concrete, Section 318, Chapter 19.

These values should be used to help determine potential corrosive characteristics of the on-sitesoils with respect to contact with the various underground materials which will be used for projectconstruction. Refer to Summary of Laboratory Results contained in Exploration Results sectionfor the complete results of the corrosivity testing performed on the site soils in conjunction withthis geotechnical exploration. The corrosion information presented is specific to the samplestested. If the actual soils that will be in contact with the structures at the site are different thanthose tested, then additional corrosion testing should be performed. Terracon is not a corrosionengineer, and our scope of work was limited to performing corrosion laboratory tests on selectedsamples, presenting these results, and providing a brief comparison of the results to selectedcriteria. A qualified corrosion engineer should be consulted if corrosion of underground utilitiesand structures is a concern.

SEISMIC CONSIDERATIONS

The seismic design requirements for buildings and other structures are based on Seismic DesignCategory. Site Classification is required to determine the Seismic Design Category for a structure.The Site Classification is based on the upper 100 feet of the site profile defined by a weightedaverage value of either shear wave velocity, standard penetration resistance, or undrained shearstrength in accordance with Section 20.4 of ASCE 7 and the International Building Code (IBC).Based on the soil properties encountered at the site and as described on the exploration logs andresults, it is our professional opinion that the Seismic Site Classification is D. Subsurfaceexplorations at this site were extended to a maximum depth of 26½ feet. The site properties belowthe boring depth to 100 feet were estimated based on our experience and knowledge of geologicconditions of the general area. Additional deeper borings or geophysical testing may be performedto further evaluate the conditions below the current boring depths and evaluate if a differentseismic site classification for the site is appropriate.

GEOTECHNICAL OVERVIEW

The site appears suitable for the proposed construction based upon geotechnical conditionsencountered in the borings, and provided our recommendations contained in this report are properlyimplemented in the design and construction.

n The on-site near surface soils generally consist of sandy lean clay and clayey sand soils.Field penetration test results near shallow foundation depths indicate that the consistency



of the near surface clay soils is generally medium stiff to very stiff and the relative densityof the near surface sand soils are generally medium dense to dense.

n Based on the results of the field and our laboratory testing, the near surface natural sitesoils have low penetration resistance, elevated moisture contents and low in-situ drydensity and are therefore not considered suitable for support of shallow foundations intheir current condition. We recommend these soils be over-excavated, moistureconditioned, and compacted as engineered fill to support shallow foundations as outlinedin the Earthwork section of this report.

n The on-site near surface soils exhibited moderate to high expansion potential. Therefore,the upper 24 inches of subgrade soils beneath lightly loaded structural elements (e.g.,interior slab-on-grade floor slabs) should consist of imported low volume change materials.Refer to the Earthwork section of the report for site preparation recommendations.

n Asphalt concrete and rigid pavement systems are considered suitable for this site. ThePavements section addresses the design of the pavement systems.

n Expansive soils are present on this site. This report provides recommendations to helpmitigate the effects of soil shrinkage and expansion. However, even if these proceduresare followed, some movement and (at least minor) cracking in the structure should beanticipated. The severity of cracking and other (cosmetic) damage such as uneven floorslabs will probably increase if any modification of the site results in excessive wetting ordrying of the expansive soils.

n All grades must provide effective drainage away from the building during and afterconstruction. Water permitted to pond next to the building can result in greater soilmovements than those discussed in this report. These greater movements can result inunacceptable differential floor slab movements, cracked slabs and walls, and roof leaks.Estimated movements described in this report are based on effective drainage for the lifeof the structure and cannot be relied upon if effective drainage is not maintained.

n Exposed ground should be sloped at a minimum 5 percent away from the building for atleast 10 feet beyond the perimeter of the building. After building construction andlandscaping, we recommend verifying final grades to document that effective drainagehas been achieved. Grades around the structure should also be periodically inspectedand adjusted as necessary, as part of the structure’s maintenance program.

n Based on the site soil properties, the site is classified as Site Class D in accordance withChapter 20 of ASCE 7 as required by the 2012 International Building Code.



Geotechnical engineering recommendations for foundation systems and other earth connectedphases of the project are outlined below. The recommendations contained in this report are basedupon the results of field and laboratory testing (included in the Exploration Results section),engineering analyses, and our current understanding of the proposed project.

The General Comments section provides an understanding of the report limitations.

SHALLOW FOUNDATIONS

If the site has been prepared in accordance with the requirements noted in Earthwork, thefollowing design parameters are applicable for shallow foundations.

Design Parameters – Spread Footings for Compressive Loads

The proposed shallow spread foundations for the project can be supported by shallow spreadfootings bearing on engineered fill. Design recommendations for foundations for these structuresand related structural elements are presented as follows.

Design Item Description/RecommendationsMaximum Net Allowable

Bearing Pressure 1,2 2,500 psf

Minimum Embedment DepthBelow finished grade 3 18 inches

Bearing MaterialCompacted engineered fill placed within the geometricconfigurations and depths below footings as outlined in

Earthwork section of this report.Minimum footing

dimensionsIsolated Column Footings: 24 inchesContinuous Wall Footings: 18 inches

Estimated totalsettlement 2 1 inch or less

Estimated differentialsettlement 2 ¾ of the total settlement

1. The maximum net allowable bearing pressure is the pressure in excess of the minimum surroundingoverburden pressure at the footing base elevation. The allowable bearing pressure may be increased byone-third when considering the alternative load combinations of Section 1605.3.2 of the 2012 InternationalBuilding Code, however, it should not be increased when loads are determined by the basic allowablestress design load combinations of Section 1605.3.1.

2. Values provided are for maximum loads noted in the Project Description.3. Finished grade is defined as the lowest adjacent grade within 5 feet of the foundation for perimeter (or

exterior) footings and finished floor level for interior footings.



Footings, foundations, and walls should be reinforced as necessary to reduce the potential fordistress caused by differential foundation movement. The use of joints at openings or otherdiscontinuities in walls is recommended.

Foundation excavations should be observed by the geotechnical engineer. If the soil conditionsencountered differ significantly from those presented in this report, supplementalrecommendations will be required.

Footings Subject to Uplift

Reinforced concrete dead-man foundations, cast-in excavations against undisturbed subsoils arerecommended for resistance to uplift. Footing or dead-man foundations may be designed usingthe cone method. The equation for determining the ultimate uplift capacity as a function of footingor dead-man foundation dimension, foundation depth, and soil weight is presented below:

Tu = 0.63g x D2 x (B + L) + W

Where: Tu = Ultimate uplift capacity (lbs)g = Unit weight of soil (lbs/ft3)*D = Depth to base of footing/dead-man foundation below final grade (ft)B = Width of footing/dead-man foundation (ft)L = Length of footing/dead-man foundation (ft)W = Weight of footing/dead-man + weight of soil directly over the top of thefooting/block (lbs)

*A unit weight (g) of 110 pcf is recommended for soil (either undisturbed orcompacted backfill) at this site.

The design uplift resistance should be calculated by dividing the ultimate resistance obtained fromthe equation above by an appropriate factor of safety. A factor of safety of at least 2 isrecommended for live uplift loads in the analysis.

Foundation Construction Considerations

As noted in Earthwork section of this report, the footing excavations should be evaluated underthe direction of the Geotechnical Engineer. The base of all foundation excavations should be freeof water and loose soil, prior to placing concrete. Concrete should be placed soon after excavatingto reduce bearing soil disturbance. Care should be taken to prevent wetting or drying of thebearing materials during construction. Extremely wet, soft or disturbed material in the bottom ofthe footing excavations should be removed before foundation concrete is placed. Should the soilsat bearing level become excessively disturbed or saturated, the affected soil should be removedprior to placing concrete.



LATERAL EARTH PRESSURES

Design Parameters

The lateral earth pressure recommendations herein are applicable to the design of footings andrigid retaining walls subject to slight rotation, such as cantilever, or gravity type concrete walls.

Earth Pressure Design Case1 Design Recommendation2,4

Active Case (Ka) 40 psf/ft

Passive Case (Kp) 360 psf/ft

At-Rest Case (Ko) 60 psf/ft

Coefficient of Base Friction 0.453

Total Unit Weight 105 pcf

1. For active earth pressure, wall must rotate about base, with top lateral movements 0.002 H to 0.004 H,where H is wall height. For passive earth pressure, wall must move horizontally to mobilize resistance.

2. The design values are based on utilizing on-site soils as backfill placed and compacted as outlined in theEarthwork section of this report. Compaction of each lift adjacent to walls should be accomplished withhand-operated tampers or other lightweight compactors.

3. The coefficient of base sliding should be reduced to 0.35 when used in conjunction with passive pressure.4. The lateral earth pressures herein do not include any factor of safety, they assume drained conditions

and a horizontal backfill, and they are not applicable for submerged soils/hydrostatic loading. Additionalrecommendations may be necessary if such conditions are to be included in the design.

FLOOR SLABS

Floor slabs (non-pavement areas) should be designed based on the following geotechnicalrecommendations:

Design parameters for floor slabs assume the requirements for Earthwork have been followed.Specific attention should be given to positive drainage away from the structure and positive drainageof the aggregate base beneath the floor slab.

Floor Slab Design Parameters

Item Description

Interior building floor system Slab-on-grade concreteSubbase 4 inches of compacted aggregate base course materials

Floor slab support2

A minimum of 24 inches of subgrade soils beneath interior slab-on-grade floor slabs and aggregate subbase should consist of

imported low volume change materials and placed in accordancethe Earthwork section of this report.



Item Description

Modulus of subgrade reaction1 175 pounds per square inch per inch (psi/in) for point loads1. Modulus of subgrade reaction is an estimated value based upon our experience with the subgrade

condition, the requirements noted in Earthwork section of this report, and the floor slab support as notedin this table.

2. Thicker sections of non-expansive imported fill will further reduce potential slab movement. Dependingupon final floor elevations, removal of existing soils may be required to accommodate the specifiedthickness of non-expansive materials. As an alternative, consideration could be given to the use ofchemical stabilization, such as lime treatment, to reduce or eliminate the expansive potential of the on-sitesoils.

Additional floor slab design and construction recommendations are as follows:

n Positive separations and/or isolation joints should be provided between slabs and allfoundations, columns or utility lines to allow independent movement.

n Control joints should be provided in slabs to control the location and extent of cracking.

n Other design and construction considerations, as outlined in the ACI Design Manual, Section302.1R are recommended.

n Some differential movement of a slab-on-grade floor system is possible should the subgradesoils become elevated in moisture content. Such movements are anticipated to be withingeneral tolerance (i.e., less than 1 inch) for normal slab-on-grade construction. To reducepotential slab movements, the subgrade soils should be prepared as outlined in the Earthworksection of this report.

n The use of a vapor retarder or barrier should be considered beneath concrete slabs on gradethat will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings,or when the slab will support equipment sensitive to moisture. When conditions warrant theuse of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier.

Floor Slab Construction Considerations

Finished subgrade, within and for at least 10 feet beyond the floor slab, should be protected fromtraffic, rutting, or other disturbance and maintained in a relatively moist condition until floor slabs areconstructed. If the subgrade should become disturbed or desiccated prior to construction of floorslabs, the affected material should be removed and structural fill should be added to replace theresulting excavation. Final conditioning of the finished subgrade should be performed immediatelyprior to placement of the floor slab support course.



The on-site surface and near surface clay soils exhibited moderate to high expansion potentials.Therefore, a minimum of 24 inches of subgrade soils beneath interior slab-on-grade floor slabsand aggregate subbase should consist of either imported low volume change materials orapproved on-site low volume change soils (e.g., deeper poorly graded sands and silty sands).

The Geotechnical Engineer should approve the condition of the floor slab subgrades immediatelyprior to placement of the floor slab support course, reinforcing steel, and concrete. Attention shouldbe paid to high traffic areas that were rutted and disturbed earlier, and to areas where backfilledtrenches are located.

PAVEMENTS

General Pavement Comments

Pavement designs are provided for the traffic conditions and pavement life conditions as noted inProject Description. A critical aspect of pavement performance is site preparation. Thepavement designs noted in this section must be applied to the site that has been prepared asrequired in the Earthwork section.

The design of flexible pavements for the project was based on the procedures of the NationalAsphalt Pavement Association (NAPA). These design procedures are specific to low-volume (lowtraffic) pavements such as those that will be constructed at this site. Portland Cement Concrete(PCC) pavement thicknesses are based on the American Concrete Institute (ACI) designrecommendations.

The design of the recommended pavement sections was based on the following NAPA criteria:

n Traffic Class I for automobile drives and parking areas includes a maximum of 7,000Equivalent Single 18-kip Axle Loads (ESAL’s) over the design life of the pavement

n Traffic Class II for main drives and light truck drives areas includes a maximum of 27,000ESAL’s over the design life of the pavement

n A soil characterization of “poor” based on the subgrade soils encountered at the site andexpected at pavement subgrade elevation

n A pavement design life of 20 years



Pavement Section Thicknesses

Pavement sections based upon a more detailed pavement design could be provided if specifictraffic loading, frequencies, and desired pavement design life are provided. As a minimum, wesuggest the following typical pavement sections be considered:

Pavement Area Alternative

Recommended Pavement Section Thickness (inches)1

AsphaltConcrete

PortlandCement

Concrete

AggregateBase Course Total

Automobile Drives &Parking Areas

Flexible 3.0 -- 4.0 7.0

Rigid -- 5.0 4.0 9.5

Main Drives & LightTruck Drives

Flexible 3.5 -- 6.0 9.5

Rigid -- 6.0 4.0 10.5

Trash Enclosures Rigid -- 6.0 4.0 10.51. Due to the expansive nature of the clay subgrade soils, the use of lime stabilization of the upper 12 inches of

subgrade should be considered to reduce the effect of the shrink/swell movements of the expansive subgradesoil. However, some effects of the shrink/swell should still be expected. Reducing and/or removing thestabilized subgrade soils below the recommended 12 inches will greatly increase the risk of pavement cracking,grade and drainage impacts, trip hazards and premature pavement failure due to swelling subgrade soils. Thelime stabilization should be in accordance with Section 309 of the specifications outlined in the MaricopaAssociation of Governments (5MAG, 2018). A lime stabilization mix design should be conducted prior toconstruction.

Pavement performance is affected by its surroundings. In addition to providing preventivemaintenance, the civil engineer should consider the following recommendations in the design andlayout of pavements:

Final grade adjacent to paved areas should slope down from the edges at a minimum of2%; and

The subgrade and pavement surface should have a minimum 2% slope to promoteproper surface drainage.

5 Maricopa Association of Governments, 2018 Revision to the 2015 Edition, Uniform Standard Specifications andDetails for Public Works Construction, Arizona.



Design and Construction Considerations

Materials and construction of pavements for the project should be in accordance with therequirements and specifications of the Maricopa Association of Governments (6MAG, 2018).Base course or pavement materials should not be placed when the surface is wet. Surfacedrainage should be provided away from the edge of paved areas to minimize lateral moisturetransmission into the subgrade.

All concrete for rigid pavements should have a minimum 28-day compressive strength of 4,000psi (i.e. MAG AA or equivalent), and be placed with a maximum slump of 4 inches. Although notrequired for structural support, a minimum 4-inch thick base course layer is recommendedbeneath concrete pavements to help reduce the potential for slab curl, shrinkage cracking, andsubgrade “pumping” through joints. Proper joint spacing will also be required to prevent excessiveslab curling and shrinkage cracking. All joints should be sealed to prevent entry of foreign materialand dowelled where necessary for load transfer.

Pavement Maintenance

Future performance of pavements constructed on the soils at this site will be dependent uponseveral factors, including:

n maintaining stable moisture content of the subgrade soils; and,

n providing for a planned program of preventative maintenance.

Preventative maintenance should be planned and provided for through an on-going pavementmanagement program to enhance future pavement performance. Preventative maintenanceactivities are intended to slow the rate of pavement deterioration, and to preserve the pavementinvestment.

Preventative maintenance consists of both localized maintenance (e.g. crack sealing andpatching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually thefirst priority when implementing a planned pavement maintenance program and provides thehighest return on investment for pavements.

EARTHWORK

The following presents recommendations for site preparation, excavation, subgrade preparationand placement of engineered fills on the project. The recommendations presented for design and

6 Maricopa Association of Governments, 2018, Uniform Standard Specifications and Details for Public WorksConstruction, Arizona.



construction of earth supported elements including foundations, slabs and pavements arecontingent upon following the recommendations outlined in this section.

Earthwork on the project should be observed and evaluated by Terracon. The evaluation ofearthwork should include observation and testing of engineered fill, subgrade preparation,foundation bearing soils, and other geotechnical conditions exposed during the construction ofthe project.

Site Preparation

Strip and remove existing crop, organic materials, debris, and other deleterious materials fromproposed buildings and pavement areas. Exposed surfaces should be free of mounds anddepressions which could prevent uniform compaction. The site should be initially graded to createa relatively flat surface to receive fill, and to provide for a relatively uniform thickness of fill beneathproposed buildings and pavements.

Although evidence of fills or underground facilities such as septic tanks, cesspools, basements,and utilities was not observed during the site reconnaissance, such features could be encounteredduring construction. If unexpected fills or underground facilities are encountered, such featuresshould be removed, and the excavation thoroughly cleaned prior to backfill placement and/orconstruction.

Subgrade Preparation

In shallow foundation areas, engineered fill should extend below proposed shallow spreadfootings to the depths indicated in the following table.

Structure Depth of Fill Below Footings Lateral Extent of Fill Beyond theEdge of Footings

Proposed BuildingsA minimum of 2 feet below the footingbottom, or 4 feet below existing sitegrade, whichever depth is greater

A minimum of 5 feet horizontallybeyond the edges of footings

The upper 24 inches of subgrade soils beneath interior slab-on-grade floor slabs and aggregatesubbase should consist of imported low volume change materials and placed as engineered fill.

In pavement areas not stabilized with lime, subgrade soils beneath pavements should bescarified, moisture conditioned and compacted to a minimum depth of 10 inches. The moisturecontent and compaction of subgrade soils should be maintained until slab or pavementconstruction.



Exterior Slab Subgrade Preparation

Compacted subgrade or existing clay soils will expand with increasing moisture content; therefore,exterior concrete grade slabs may heave, resulting in cracking or vertical offsets. The potentialfor damage would be greatest where exterior slabs are constructed adjacent to the existingbuilding, building addition, or other structural elements. To reduce the potential for damagecaused by movement, we recommend:

n Exterior slabs be supported on fill with no, or very low expansion potential

n Strict moisture-density control during placement of subgrade fills

n Placement of effective control joints on relatively close centers and isolation joints betweenslabs and other structural elements

n Provision for adequate drainage in areas adjoining the slabs

n Use of designs which allow vertical movement between the exterior slabs and adjoiningstructural elements

To further reduce the potential of movement of exterior slabs, consideration should be given to:

n Constructing slabs with a stem or key-edge, a minimum of 6 inches in width and at least12 inches below grade;

n Providing structural exterior slabs supported on foundations similar to the buildings; or,

n Constructing slabs on lime treated soils similar to the recommendations for support ofinterior slabs.

Lime Stabilized Subgrade

Lime stabilized subgrade should be treated in accordance with Section 309 of MAG 2018.

Fill Material Types

All fill materials should be inorganic soils free of vegetation, debris, and fragments larger than fourinches in size. Pea gravel or other similar non-cementitious, poorly-graded materials should notbe used as fill or backfill without the prior approval of the geotechnical engineer.

Clean on-site soils or approved imported materials may be used as fill material for the following:



Fill Type 1 USCS Classification Acceptable Location for Placement

On-Site Soils CL, SC

The on-site soils are considered suitable for useas engineered fill with the exception of within the

upper 24 inches of finished subgrade beneathinterior floor slabs and aggregate base course,

and beneath exterior slabs adjacent to thebuilding.

Low Volume Change:Imported Material Varies All locations and elevations

1. Controlled, compacted fill should consist of approved materials that are free of organic matter, debris,and oversized materials. A sample of each material type should be submitted to the geotechnicalengineer for evaluation.

Imported soils for use as fill material on the project should conform to low volume changematerials as indicated in the following specifications. Approved on-site soils (e.g., deeper poorlygraded sands and silty sands) meeting the following specifications can also be used as lowvolume change materials.

Percent Finer by WeightGradation (ASTM C 136)

4" ......................................................................................................... 100No. 4 Sieve ..................................................................................... 50-100No. 200 Sieve ............................................................ 15 (min) to 45 (max)

n Liquid Limit ....................................................................... 30 (max)n Plasticity Index ................................................................. 12 (max)n Maximum expansive potential (%)* ............................................ 1.5

*Measured on a sample compacted to approximately 95 percent of the ASTM D698maximum dry density at about 3 percent below optimum water content. The sample isconfined under a 100 psf surcharge and submerged/inundated.

Engineered fill should be placed and compacted in horizontal lifts, using equipment andprocedures that will produce recommended moisture contents and densities throughout the lift.Fill lifts should not exceed 10 inches loose thickness.

Base course should conform to the Maricopa Association of Governments (MAG) specifications.

Fill Compaction Requirements

Engineered fill should meet the following compaction and moisture requirements:



Material Type and Location

Per the Standard Proctor Test (ASTM D 698)

MinimumCompactionRequirement

(%)

Range of Moisture Contents forCompaction (referenced fromoptimum moisture content)Minimum Maximum

On-site soils:

Beneath foundations 95 -1% +3%Beneath floor slabs (except the upper 24 inches) 95 At optimum +3%

Beneath pavements 95 -2% +2%Beneath Depths Greater than 5 feet 100 -3% +3%

Imported soils:

Beneath foundations 95 -3% +3%Beneath floor slabs (within upper 24 inches) 95 -2% +2%

Beneath pavements 95 -2% +2%Beneath Depths Greater than 5 feet 100 -3% +3%

Aggregate base (beneath concrete slabs) 95 -3% +3%

Aggregate base (beneath asphalt pavements) 100 -2% +2%

Aggregate base (beneath concrete pavements) 95 -3% +3%

Miscellaneous backfill 95 -3% +3%

1. The moisture content and compaction should be measured for each lift of engineered fill during placement.Should the results of the in-place density tests indicate the specified moisture or compaction limits have notbeen met, the area represented by the test should be reworked and retested as required until the specifiedmoisture and compaction requirements are achieved.

Utility Trench Backfill

Utility trenches are a common source of water infiltration and migration. Utility trenchespenetrating beneath structures should be effectively sealed to restrict water intrusion and flowthrough the trenches, which could migrate below the structures. The trench should provide aneffective trench plug that extends at least 5 feet from the face of the structure exterior. The plugmaterial should consist of cementitious flowable fill or low permeability clay. The trench plugmaterial should be placed to surround the utility line. If used, the clay trench plug material shouldbe placed and compacted to comply with the water content and compaction recommendations forstructural fill stated previously in this report.

Earthwork Factors

The earthwork factors are based on a comparison of the in-situ dry densities from ring samplesto the density of bulk samples compacted to 95 percent of maximum dry density as determined



by ASTM D698. The estimated shrinkage of the upper roughly 5 feet of the site soils when usedas compacted fill is expected to be in the range of 1 to 14 percent shrinkage based on compactingthe materials to a minimum of 95 percent of the maximum dry density determined in accordancewith ASTM D698. Based on the average earthwork factor estimates, we recommend a shrinkageestimate of 4 percent be used for design purposes.

These estimates are general in nature, and are based on our experience, limited data from ourfield exploration, and the soil conditions we encountered at the site. Earthwork factors may varydependent upon the actual subsurface conditions, which may include variations in soil gradationsand gravel contents. Earthwork values are also expected to be less in areas subjected to lowerlevels of compaction or where the existing natural soils are denser. Conversely, earthwork valuesare also expected to be more in areas subjected to higher levels of compaction or where theexisting natural soils are less dense.

A ground compaction factor of approximately 0.1 feet should be applied when estimating thechange in elevation of the native soil surface due to scarification, moisture conditioning and re-compaction prior to fill placement.

Grading and Drainage

Positive drainage should be provided during construction and maintained throughout the life ofthe development. Infiltration of water into utility trenches or foundation excavations should beprevented during construction. Planters and other surface features which could retain water inareas adjacent to structures or pavements should be sealed or eliminated. In areas wheresidewalks or paving do not immediately adjoin the structure, we recommend that protective slopesbe provided with a minimum grade of approximately five percent for at least 10 feet from perimeterwalls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should becompacted to the densities outlined herein and be free of all construction debris to reduce thepossibility of moisture infiltration.

Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when theground surface beneath such features is not protected by exterior slabs or paving. Sprinklersystems should not be installed within five feet of foundation walls. Landscaped irrigationadjacent to the foundation systems should be minimized or eliminated.

All grades must provide effective drainage away from all structures during and after construction.Water permitted to pond next to structures can result in greater soil movements than thosediscussed in this report. These greater movements can result in unacceptable differential floorslab movements, cracked slabs and walls, and roof leaks. Estimated movements described inthis report are based on effective drainage for the life of the structures and cannot be relied uponif effective drainage is not maintained.



Earthwork Construction Considerations

It is anticipated that shallow excavations for the proposed construction can be accomplished withconventional earthmoving equipment.

If unstable conditions exist or develop, workability may be improved by scarifying and drying.Over-excavation of wet zones and replacement with granular materials may be necessary. Useof lime, fly ash, cement, geotextiles or geogrid could also be considered as a stabilizationtechnique. Laboratory evaluation is recommended to determine the effect of chemicalstabilization on subgrade soils prior to construction. Lightweight excavation equipment may berequired to reduce subgrade pumping.

Upon completion of filling and grading, care should be taken to maintain the subgrade moisturecontent prior to construction of floor slabs. Construction traffic over the completed subgradeshould be avoided to the extent practical. The site should also be graded to prevent ponding ofsurface water on the prepared subgrades or in excavations. If the subgrade should becomedesiccated, saturated, or disturbed, the affected material should be removed or these materialsshould be scarified, moisture conditioned, and recompacted prior to floor slab construction andobserved by Terracon.

Surface water should not be allowed to pond on the site and soak into the soil during construction.Construction staging should provide drainage of surface water and precipitation away from thebuilding and other structure areas. Any water that collects over or adjacent to construction areasshould be promptly removed, along with any softened or disturbed soils. Surface water control inthe form of sloping surfaces, drainage ditches and trenches, and sump pits and pumps will beimportant to avoid ponding and associated delays due to precipitation and seepage.

As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926,Subpart P, “Excavations” and its appendices, and in accordance with any applicable local, state,and federal safety regulations. The contractor should be aware that slope height, slopeinclination, and excavation depth should in no instance exceed those specified by these safetyregulations. Flatter slopes than those dictated by these regulations may be required dependingupon the soil conditions encountered and other external factors. These regulations are strictlyenforced and if they are not followed, the owner, contractor, and/or earthwork and utilitysubcontractor could be liable and subject to substantial penalties.

Construction site safety is the sole responsibility of the contractor who controls the means,methods and sequencing of construction operations. Under no circumstances shall theinformation provided herein be interpreted to mean that Terracon is assuming any responsibilityfor construction site safety or the contractor's activities; such responsibility shall neither be impliednor inferred.



Construction Observation and Testing

The exposed subgrade and each lift of compacted fill should be tested, evaluated and reworked,as necessary, until approved by the geotechnical engineer’s representative prior to placement ofadditional lifts of fill. We recommend that each lift of fill be tested for density and moisture contentat a minimum frequency of one test for every 5,000 square feet of compacted fill in the structureareas or a minimum of 3 density tests per lift (with the greater number of density tests to govern).We recommend one density and moisture content test for every 300 linear feet of compactedutility trench backfill. If engineered fill is placed beneath individual structures, we recommend atleast one density and moisture content test per each vertical lift per structure.

Terracon should be retained during the construction phase of the project to observe earthworkand to perform necessary tests and observations during subgrade preparation; proofrolling;placement and compaction of controlled compacted fills; backfilling of excavations into thecompleted subgrade, and just prior to construction of building floor slabs.

GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnicalconditions in the area, and the data obtained from our site exploration. Natural variations will occurbetween exploration point locations or due to the modifying effects of construction or weather.The nature and extent of such variations may not become evident until during or after construction.Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provideobservation and testing services during pertinent construction phases. If variations appear, wecan provide further evaluation and supplemental recommendations. If variations are noted in theabsence of our observation and testing services on-site, we should be immediately notified sothat we can provide evaluation and supplemental recommendations.

Our Scope of Services does not include either specifically or by implication any environmental orbiological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention ofpollutants, hazardous materials or conditions. If the owner is concerned about the potential forsuch contamination or pollution, other studies should be undertaken.

Our services and any correspondence or collaboration through this system are intended for thesole benefit and exclusive use of our client for specific application to the project discussed andare accomplished in accordance with generally accepted geotechnical engineering practices withno third-party beneficiaries intended. Any third-party access to services or correspondence issolely for information purposes to support the services provided by Terracon to our client.Reliance upon the services and any work product is limited to our client and is not intended forthird parties. Any use or reliance of the provided information by third parties is done solely at theirown risk. No warranties, either express or implied, are intended or made.



Site characteristics as provided are for design purposes and not to estimate excavation cost. Anyuse of our report in that regard is done at the sole risk of the excavating cost estimator as theremay be variations on the site that are not apparent in the data that could significantly impactexcavation cost. Any parties charged with estimating excavation costs should seek their own sitecharacterization for specific purposes to obtain the specific level of detail necessary for costing.Site safety, and cost estimating including, excavation support, and dewateringrequirements/design are the responsibility of others. If changes in the nature, design, or locationof the project are planned, our conclusions and recommendations shall not be considered validunless we review the changes and either verify or modify our conclusions in writing.


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ATTACHMENTS



SITE LOCATION AND EXPLORATION PLANS

Contents:

Site Location PlanExploration Plan

Note: All attachments are one page unless noted above.

SITE LOCATIONProposed San Tan Valley Administration Complex San Tan Valley, ArizonaMarch 26, 2019 Terracon Project No. 65185202

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When paragraph markers are turned on you may notice a line of hidden text above andoutside the table – please leave that alone. Limit editing to inside the table.

SITE LOCA TION LANDSCAPE

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

EXPLORATION PLANProposed San Tan Valley Administration Complex San Tan Valley, ArizonaMarch 26, 2019 Terracon Project No. 65185202

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EXPLORATION P LAN PORTRAI T

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS



EXPLORATION RESULTS

Contents:

General NotesUnified Soil Classification SystemBoring Logs (B-1 thru B-8, CMP-1, CMP-1, and P-1 thru P-4,)Double Ring Infiltration Test Summary (DR-1 and DR-2)Atterberg LimitsGrain Size DistributionMoisture Density Relationship (2 pages)Consolidation/Swell (7 pages)Summary of Laboratory Results (2 pages)

Note: All attachments are one page unless noted above.

Proposed San Tan Valley Administration Complex San Tan Valley, Arizona

March 26, 2019 Terracon Project No. 65185202

less than 500

1,000 to 2,000

> 8,000

UnconfinedCompressive Strength

Qu, (psf)

500 to 1,000

2,000 to 4,000

4,000 to 8,000

AugerCuttings

RingSampler

StandardPenetrationTest

Trace

PLASTICITY DESCRIPTION

Water levels indicated on the soil boring logs arethe levels measured in the borehole at the timesindicated. Groundwater level variations will occurover time. In low permeability soils, accuratedetermination of groundwater levels is notpossible with short term water levelobservations.

DESCRIPTION OF SYMBOLS AND ABBREVIATIONSGENERAL NOTES

> 30

11 - 30

1 - 10Low

Non-plastic

Plasticity Index

#4 to #200 sieve (4.75mm to 0.075mm

Boulders

12 in. to 3 in. (300mm to 75mm)Cobbles

3 in. to #4 sieve (75mm to 4.75 mm)Gravel

Sand

Passing #200 sieve (0.075mm)Silt or Clay

Particle Size

Water Level Aftera Specified Period of Time

Water Level After aSpecified Period of Time

Water InitiallyEncountered

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of theirdry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soilshave less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic,and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituentsmay be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils aredefined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

GRAIN SIZE TERMINOLOGY

RELATIVE PROPORTIONS OF FINESRELATIVE PROPORTIONS OF SAND AND GRAVEL

DESCRIPTIVE SOIL CLASSIFICATION

LOCATION AND ELEVATION NOTES

SAMPLING WATER LEVEL FIELD TESTSN

(HP)

(T)

(DCP)

UC

(PID)

(OVA)

Standard Penetration TestResistance (Blows/Ft.)

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Unconfined CompressiveStrength

Photo-Ionization Detector

Organic Vapor Analyzer

Medium

0Over 12 in. (300 mm)

>12

5-12

<5

Percent ofDry Weight

TermMajor Component of Sample

Modifier

With

Trace

Descriptive Term(s) ofother constituents

>30Modifier

<15

Percent ofDry Weight

Descriptive Term(s) ofother constituents

With 15-29

High

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. Theaccuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographicalsurvey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined fromtopographic maps of the area.

Descriptive Term(Consistency)

0 - 6

CONSISTENCY OF FINE-GRAINED SOILS

Hard

Very Loose

Loose

Medium Dense

Dense

Very Dense

Descriptive Term(Density)

Standard Penetrationor N-ValueBlows/Ft.

0 - 3

4 - 9 7 - 18

10 - 29 19 - 58

30 - 50 59 - 98

> 50 > 99 Very Stiff

Standard Penetration orN-Value

Blows/Ft.

Ring SamplerBlows/Ft.

Ring SamplerBlows/Ft.

5 - 9

Stiff

Medium Stiff

Soft

Very Soft

(50% or more passing the No. 200 sieve.)Consistency determined by laboratory shear strength testing, field visual-manual

procedures or standard penetration resistance

STRENGTH TERMS

RELATIVE DENSITY OF COARSE-GRAINED SOILS

(More than 50% retained on No. 200 sieve.)Density determined by Standard Penetration Resistance

2 - 4

4 - 8

8 - 15

15 - 30

> 30

0 - 1

3 - 4

< 3

10 - 18

19 - 42

> 42

UNIFIED SOIL CLASSIFICATION SYSTEM


UNIFIED SOI L CLASSI FICATI ON SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests ASoil Classification

GroupSymbol Group Name B

Coarse-Grained Soils:More than 50% retainedon No. 200 sieve

Gravels:More than 50% ofcoarse fractionretained on No. 4 sieve

Clean Gravels:Less than 5% fines C

Cu ³ 4 and 1 £ Cc £ 3 E GW Well-graded gravel F

Cu < 4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F

Gravels with Fines:More than 12% fines C

Fines classify as ML or MH GM Silty gravel F, G, H

Fines classify as CL or CH GC Clayey gravel F, G, H

Sands:50% or more of coarsefraction passes No. 4sieve

Clean Sands:Less than 5% fines D

Cu ³ 6 and 1 £ Cc £ 3 E SW Well-graded sand I

Cu < 6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I

Sands with Fines:More than 12% fines D

Fines classify as ML or MH SM Silty sand G, H, I

Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils:50% or more passes theNo. 200 sieve

Silts and Clays:Liquid limit less than 50

Inorganic:PI > 7 and plots on or above “A”line J

CL Lean clay K, L, M

PI < 4 or plots below “A” line J ML Silt K, L, M

Organic:Liquid limit - oven dried

< 0.75 OL Organic clay K, L, M, N

Liquid limit - not dried Organic silt K, L, M, O

Silts and Clays:Liquid limit 50 or more

Inorganic:PI plots on or above “A” line CH Fat clay K, L, M

PI plots below “A” line MH Elastic Silt K, L, M

Organic:Liquid limit - oven dried

< 0.75 OH Organic clay K, L, M, P

Liquid limit - not dried Organic silt K, L, M, Q

Highly organic soils: Primarily organic matter, dark in color, and organic odor PT PeatA Based on the material passing the 3-inch (75-mm) sieve.B If field sample contained cobbles or boulders, or both, add “with cobbles

or boulders, or both” to group name.C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded

gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorlygraded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well-gradedsand with silt, SW-SC well-graded sand with clay, SP-SM poorly gradedsand with silt, SP-SC poorly graded sand with clay.

E Cu = D60/D10 Cc =6010

230

DxD

)(D

F If soil contains ³ 15% sand, add “with sand” to group name.G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

H If fines are organic, add “with organic fines” to group name.I If soil contains ³ 15% gravel, add “with gravel” to group name.J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.K If soil contains 15 to 29% plus No. 200, add “with sand” or “with

gravel,” whichever is predominant.L If soil contains ³ 30% plus No. 200 predominantly sand, add

“sandy” to group name.MIf soil contains ³ 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.NPI ³ 4 and plots on or above “A” line.OPI < 4 or plots below “A” line.P PI plots on or above “A” line.QPI plots below “A” line.

5-6

50/2"

10-19

8-9-9N=18

5718

17

12

96

98

108

47-17-30

SANDY LEAN CLAY (CL), trace gravel, fine to medium sand, medium tohigh plasticity, light brown, stiff

CLAYEY SAND WITH GRAVEL (SC), fine to coarse sand, low plasticity,brown, very dense

medium dense

Boring Terminated at 15.5 Feet

4.0

15.5

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

TH

IS B

OR

ING

LO

G IS

NO

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.GP

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N_D

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AT

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PLA

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.GD

T 3

/21/

19

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R L

EV

EL

OB

SE

RV

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ION

S

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H (

Ft.)

5

10

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Page 1 of 1

Advancement Method:8" O.D. Hollow Stem Auger

Abandonment Method:Boring backfilled with auger cuttings upon completion.

4685 S Ash Ave, Ste H-4Tempe, AZ

Notes:

Project No.: 65185202

Drill Rig: D-120

BORING LOG NO. B-1Arrington Watkins ArchitectsCLIENT:Phoenix, Arizona

Driller: D&S

Boring Completed: 01-31-2019

PROJECT: Proposed San Tan Valley AdministrationComplex

See Exploration and Testing Procedures for adescription of field and laboratory proceduresused and additional data (If any).

See Supporting Information for explanation ofsymbols and abbreviations.

NW of Bella Vista Rd & Sierra Vista Dr San Tan Valley, ArizonaSITE:

Boring Started: 01-31-2019WATER LEVEL OBSERVATIONSGroundwater not encountered

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION

Latitude: 33.1656° Longitude: -111.5179°

See Exploration Plan

GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

12-14

16-20

12-15

8-11-13N=24

14

8

12

99

107

108

SANDY LEAN CLAY (CL), fine to coarse sand, low to medium plasticity,brown, very stiff

clayey sand lense

trace gravel, fine to medium sand

fine to coarse sand

fine to medium sand, no gravel

Boring Terminated at 15.5 Feet15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

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D F

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M O

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O S

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G-N

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ELL

651

852

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RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

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RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

6-7

20-24

14-19

10-15-19N=34

5213

11

16

105

116

105

38-15-23

SANDY LEAN CLAY (CL), fine to coarse sand, medium plasticity, brown,stiff

trace gravel

CLAYEY SAND (SC), trace gravel, low plasticity, brown, medium dense

SANDY LEAN CLAY (CL), trace gravel, fine to medium sand, mediumplasticity, brown, very stiff to hard


4.0

9.0

15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

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D F

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M O

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INA

L R

EP

OR

T.

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O S

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G-N

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ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

7-8

17-21

11-15

11-11-15N=26

20

9

12

90

89

113

SANDY LEAN CLAY (CL), trace gravel, fine to coarse sand, mediumplasticity, brown, stiff

CLAYEY SAND (SC), trace gravel, fine to coarse sand, medium plasticity,brown, medium dense

SANDY LEAN CLAY (CL), fine to medium sand, low plasticity, brown, verystiff

CLAYEY SAND (SC), trace gravel, fine to coarse sand, low plasticity,brown, medium dense


4.0

9.0

14.0

15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

9-19

15-20

22-29

12-12-18N=30

20

18

15

96

108

92

SANDY LEAN CLAY (CL), trace gravel, fine to coarse sand, mediumplasticity, brown, very stiff

CLAYEY SAND (SC), trace gravel, fine to coarse sand, medium plasticity,brown, medium dense to dense


4.0

15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

4-7

5-5

10-15

10-10-12N=22

19

18

18

94

96

101

SANDY LEAN CLAY (CL), fine to medium sand, low to medium plasticity,light brown, stiff

trace gravel, clayey sand lense

no gravel

CLAYEY SAND (SC), trace gravel, medium plasticity, brown, mediumdense


9.0

15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

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RT

LO

G-N

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ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

9-14

6-7

10-10

6-7-7N=14

10-11-16N=27

19

17

16

102

101

104

SANDY LEAN CLAY (CL), fine to medium sand, medium plasticity, lightbrown, stiff to very stiff

trace gravel

fine to coarse sand, increase in gravel content

trace gravel

Boring Terminated at 18.5 Feet18.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

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D F

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RIG

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OR

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O S

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G-N

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ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

10-14

18-30

23-29

12-13-18N=31

5717

5

24

89

115

99

50-19-31

SANDY FAT CLAY (CH), trace gravel, high plasticity, brown, very stiff

trace gravel

CLAYEY SAND WITH GRAVEL (SC), low plasticity, brown, medium dense

SANDY LEAN CLAY (CL), trace gravel, fine to medium sand, mediumplasticity, dark brown, hard

CLAYEY SAND (SC), fine to coarse sand, low plasticity, light brown, dense


4.0

9.0

14.0

15.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

2-3-3N=6

7-10-10N=20

9-10-13N=23

21-23-33N=56

15-19-21N=40

45-50/5"

SANDY LEAN CLAY (CL), fine to coarse sand, medium plasticity, darkbrown, medium stiff

trace gravel

CLAYEY SAND (SC), trace gravel, fine to coarse sand, low to mediumplasticity, brown, medium dense

SANDY LEAN CLAY (CL), fine sand, low to medium plasticity, brown, verystiff to hard

light gray and white

SILTY CLAYEY SAND (SC-SM), trace gravel, nonplastic, brown, dense tovery dense

Boring Terminated at 25 Feet

5.0

10.0

20.0

25.0


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120

BORING LOG NO. CMP-1Arrington Watkins ArchitectsCLIENT:Phoenix, Arizona

Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

2-2-3N=5

8-15-12N=27

15-15-20N=35

50/5"

10-10-18N=28

15-19-22N=41

SANDY LEAN CLAY (CL), medium plasticity, dark brown, medium stiff

CLAYEY SAND (SC), trace gravel, fine to coarse sand, low to mediumplasticity, light brown, medium dense to dense

very dense

SILTY CLAYEY SAND (SC-SM), trace gravel, fine to coarse sand, lowplasticity, medium dense to dense, red oxidation


5.0

20.0

26.5


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120

BORING LOG NO. CMP-2Arrington Watkins ArchitectsCLIENT:Phoenix, Arizona

Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

SANDY LEAN CLAY (CL), medium plasticity, dark brown

Boring Terminated at 5 Feet5.0


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120

BORING LOG NO. P-1Arrington Watkins ArchitectsCLIENT:Phoenix, Arizona

Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

SANDY LEAN CLAY (CL), fine to medium sand, medium plasticity, brown



TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

SANDY LEAN CLAY (CL), fine to medium sand, medium plasticity, lightbrown



TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

FIE

LD T

ES

TR

ES

ULT

S

Page 1 of 1




Notes:


Drill Rig: D-120


Driller: D&S







PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

ATTERBERGLIMITS

LL-PL-PI

LOCATION



GR

AP

HIC

LO

G

DEPTH

SA

MP

LE T

YP

E

Project Name:Project Location:Project Number:

Test No.: Inner Ring Area: 113.1 in2

Depth (Elev.): Inner Ring Diameter: 12.0 inTechnician: Annular space between Outer and Inner rings: 339 in2

Date: Outer Ring Diameter: 24.0 inWeather: Depth of Liquid Inner Ring: 4.00 in

Liquid Type: Depth of Liquid Annular Space: 4.00 in

Depth:Description:

Start Finish Inner RingAnnularSpace

1 7:53:00 AM 8:08:00 AM 0:15:00 509 1527 382 1124 0.8 2.32 8:08:00 AM 8:23:00 AM 0:15:00 382 1124 269 806 0.5 1.33 8:23:00 AM 8:38:00 AM 0:15:00 360 933 283 721 0.5 0.24 8:38:00 AM 8:53:00 AM 0:15:00 283 721 212 509 0.5 1.35 8:53:00 AM 9:23:00 AM 0:30:00 594 1654 530 1527 0.4 2.46 9:23:00 AM 9:53:00 AM 0:30:00 565 1781 523 1357 0.4 0.67 9:53:00 AM 10:53:00 AM 1:00:00 615 2036 530 1845 0.6 0.98 10:53:00 AM 11:53:00 AM 1:00:00 636 1866 551 1781 0.8 1.49 11:53:00 AM 12:53:00 PM 1:00:00 551 1781 467 1633 0.4 0.710 12:53:00 PM 1:53:00 PM 1:00:00 587 1887 523 1696 0.5 0.8

Annular SpaceVolume,in3

Infiltration Rate, in/hr

Soil Description0 to 3 feetSandy Lean Clay

Trial No.

TimeElapsed Time(hr:min:sec)

Volume MeasurementsStart Finish

Inner RingVolume, in3

Annular SpaceVolume, in3


DR-13 feet below surface elevationJustin Delgado3/11/2019SunnyWater

DOUBLE RING INFILTRATION TEST SUMMARYProject

San Tan Valley Administration ComplexNortheast of Bella Vista Road and Schnepf Road65185202

Test Details Test Setup

0.0

0.5

1.0

1.5

2.0

2.5

9:14 AM 10:26 AM 11:38 AM 12:50 PM 2:02 PMIncr

emen

talI

nfilt

ratio

nR

ate

in/h

r

Inner Ring

Annular Space

Project Name:Project Location:Project Number:

Test No.: Inner Ring Area: 113.1 in2

Depth (Elev.): Inner Ring Diameter: 12.0 inTechnician: Annular space between Outer and Inner rings: 339 in2

Date: Outer Ring Diameter: 24.0 inWeather: Depth of Liquid Inner Ring: 4.00 in

Liquid Type: Depth of Liquid Annular Space: 4.00 in

Depth:Description:

Start Finish Inner RingAnnularSpace

1 8:00:00 AM 8:15:00 AM 0:15:00 509 1527 382 1124 1.8 2.52 8:15:00 AM 8:30:00 AM 0:15:00 382 1124 269 806 2.5 1.73 8:30:00 AM 8:45:00 AM 0:15:00 360 933 283 721 1.0 0.84 8:45:00 AM 9:00:00 AM 0:15:00 283 721 212 509 1.3 1.55 9:00:00 AM 9:30:00 AM 0:30:00 594 1654 530 1527 3.1 3.46 9:30:00 AM 10:00:00 AM 0:30:00 565 1781 523 1357 1.2 1.07 11:00:00 AM 12:00:00 PM 1:00:00 615 2036 530 1845 1.3 0.88 12:00:00 PM 1:00:00 PM 1:00:00 636 1866 551 1781 0.9 1.49 1:00:00 PM 2:00:00 PM 1:00:00 551 1781 467 1633 0.9 0.610 2:00:00 PM 3:00:00 PM 1:00:00 587 1887 523 1696 0.7 0.6

Water

DOUBLE RING INFILTRATION TEST SUMMARYProject

San Tan Valley Administration ComplexNortheast of Bella Vista Road and Schnepf Road65185202

Test Details Test Setup

Start Finish


Annular SpaceVolume, in3


DR-13 feet below surface elevationJustin Delgado3/11/2019Sunny

Annular SpaceVolume,in3

Infiltration Rate, in/hr

Soil Description0 to 3 feetSandy Lean Clay

Trial No.

TimeElapsed Time(hr:min:sec)

Volume Measurements

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

9:00 AM 10:12 AM 11:24 AM 12:36 PM 1:48 PM 3:00 PMIncr

emen

talI

nfilt

ratio

nR

ate

in/h

r

Inner Ring

Annular Space

0

10

20

30

40

50

60

0 20 40 60 80 100

CH o

r

OH

CL o

r

OL

ML or OL

MH or OH

"U" L

ine

"A" L

ine

ATTERBERG LIMITS RESULTSASTM D4318

PLASTICITY

INDEX

LIQUID LIMIT

PROJECT NUMBER: 65185202

SITE: NW of Bella Vista Rd & Sierra Vista Dr San Tan Valley, Arizona

PROJECT: Proposed San Tan ValleyAdministration Complex

CLIENT: Arrington Watkins Architects Phoenix, Arizona


LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

AT

TE

RB

ER

G L

IMIT

S 6

5185

202

PR

OP

OS

ED

PIN

AL

CO

- C

OP

Y.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/2

1/1

9

47

38

50

17

15

19

30

23

31

CL

CL

CH

SANDY LEAN CLAY

SANDY LEAN CLAY

SANDY FAT CLAY

DescriptionUSCSFinesPIPLLLBoring ID Depth

B-1

B-3

B-8

0 - 4

0 - 4

0 - 4

57

52

57

CL-ML

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

0.0010.010.1110100

30 40 501.5 2006 810 1441 3/4 1/2 60

GRAIN SIZE IN MILLIMETERS

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS

4 3/8 3 100 1403 2

GRAIN SIZE DISTRIBUTIONASTM D422 / ASTM C136

6 16 20






LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

GR

AIN

SIZ

E: U

SC

S-2

651

852

02 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

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19

SANDY LEAN CLAY (CL)

SANDY LEAN CLAY (CL)

SANDY FAT CLAY (CH)

0.095

0.117

0.094

37.5

19

37.5

47

38

50

56.6

52.1

57.2

7.4

1.6

6.8

WC (%) LL

D30 D10 %Gravel %Fines %Clay

B-1

B-3

B-8

30

23

31

17

15

19

Boring ID Depth USCS Classification PL PI Cc Cu

D100 D60

0 - 4

0 - 4

0 - 4

Boring ID Depth %Sand %Silt

medium

B-1

B-3

B-8

coarse coarsefine fineCOBBLES

GRAVEL SANDSILT OR CLAY

0 - 4

0 - 4

0 - 4

35.9

46.3

36.0

75

80

85

90

95

100

105

110

115

120

125

130

135

0 5 10 15 20 25 30 35 40 45

Test Method

Remarks:

TEST RESULTS

PIPLLL

ATTERBERG LIMITS

47 17 30

PCF

% Maximum Dry Density

Optimum Water Content

107.1

% Percent Fines

ASTM D698 Method A

18.2

56.6

DR

Y D

EN

SIT

Y,

pcf

WATER CONTENT, %

ZAV for Gs = 2.8

ZAV for Gs = 2.7

ZAV for Gs = 2.6

Source of Material

Description of Material

MOISTURE-DENSITY RELATIONSHIPASTM D698/D1557

B-1 @ 0 - 4 feet

SANDY LEAN CLAY(CL)






LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

CO

MP

AC

TIO

N -

V2

651

8520

2 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

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19

75

80

85

90

95

100

105

110

115

120

125

130

135

0 5 10 15 20 25 30 35 40 45

Test Method

Remarks:

TEST RESULTS

PIPLLL

ATTERBERG LIMITS

50 19 31

PCF

% Maximum Dry Density

Optimum Water Content

99.9

% Percent Fines

ASTM D698 Method A

17.5

57.2

DR

Y D

EN

SIT

Y,

pcf

WATER CONTENT, %

ZAV for Gs = 2.8

ZAV for Gs = 2.7

ZAV for Gs = 2.6

Source of Material

Description of Material

MOISTURE-DENSITY RELATIONSHIPASTM D698/D1557

B-8 @ 0 - 4 feet

SANDY FAT CLAY(CH)






LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

CO

MP

AC

TIO

N -

V2

651

8520

2 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

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19

-10

-8

-6

-4

-2

0

2

4

100 1,000 10,000

AX

IAL

ST

RA

IN,

%

PRESSURE, psf

SWELL CONSOLIDATION TESTASTM D2435

NOTES: water added at 2,000 psf






LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

TC

_CO

NS

OL_

ST

RA

IN-U

SC

S 6

518

5202

PR

OP

OS

ED

PIN

AL

CO

- C

OP

Y.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/2

1/1

9

99 19B-1 SANDY LEAN CLAY (CL)2 - 3 ft

Specimen Identification Classification , pcf WC, %

-10

-8

-6

-4

-2

0

2

4

100 1,000 10,000

AX

IAL

ST

RA

IN,

%

PRESSURE, psf








LAB

OR

AT

OR

Y T

ES

TS

AR

E N

OT

VA

LID

IF S

EP

AR

AT

ED

FR

OM

OR

IGIN

AL

RE

PO

RT

.

TC

_CO

NS

OL_

ST

RA

IN-U

SC

S 6

518

5202

PR

OP

OS

ED

PIN

AL

CO

- C

OP

Y.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/2

1/1

9



B-1 0.0 - 4.0 CL 57 47 17 30 102 15.2 100 4.4 8.4 3103 224 56B-1 2.0 - 3.0 CL 96 18 1, 2

B-1 4.0 - 4.2 SC 98 17 1, 2

B-1 9.0 - 10.0 SC 108 12 1, 2B-2 2.0 - 3.0 CL 99 14 1, 2

B-2 4.0 - 5.0 CL 107 8 1, 2B-2 9.0 - 10.0 CL 108 12 1, 2

B-3 0.0 - 4.0 CL 52 38 15 23

B-3 2.0 - 3.0 CL 105 13 1, 2B-3 4.0 - 5.0 SC 116 11 1, 2

B-3 9.0 - 10.0 CL 105 16 1, 2B-4 2.0 - 3.0 CL 90 20 1, 2

B-4 4.0 - 5.0 SC 89 9 1, 2

B-4 9.0 - 10.0 CL 113 12 1, 2B-5 2.0 - 3.0 CL 96 20 1, 2

B-5 4.0 - 5.0 SC 108 18 1, 2B-5 9.0 - 10.0 SC 92 15 1, 2

B-6 2.0 - 3.0 CL 94 19 1, 2

B-6 4.0 - 5.0 CL 96 18 1, 2B-6 9.0 - 10.0 SC 101 18 1, 2

B-7 2.0 - 3.0 CL 102 19 1, 2B-7 4.0 - 5.0 CL 101 17 1, 2

B-7 9.0 - 10.0 CL 104 16 1, 2

B-8 0.0 - 4.0 CH 57 50 19 31 95 14.5 100 7.5 8.3 2530 452 85B-8 2.0 - 3.0 CH 89 17 1, 2

50pH Resistivity

(ohm-cm)Sulfates(ppm)

Chlorides(ppm)

DryDensity

(pcf)

Expansion(%)

Corrosivity

Dry Density(pcf)

Atterberg Limits

In-Situ Properties

Passing#200

Sieve (%)

Classification

PL PI

WaterContent

(%)

Remarks

Expansion Testing

Surcharge(psf)

WaterContent (%) LL

USCSSoil

Class.Expansion

IndexEI

REMARKS1. Dry Density and/or moisture determined from one or more rings of a multi-ring sample.2. Visual Classification.3. Submerged to approximate saturation.4. Expansion Index in accordance with ASTM D4829-95.5. Air-Dried Sample

BoreholeNo.

Depth(ft.)

SUMMARY OF LABORATORY RESULTS

PROJECT: Proposed San Tan Valley Administration Complex PROJECT NUMBER: 65185202



PH. 480-897-8200 FAX. 480-897-1133


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

SO

IL P

RO

PE

RT

IES

2 6

518

520

2 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

B-8 4.0 - 5.0 SC 115 5 1, 2B-8 9.0 - 10.0 CL 99 24 1, 2

CMP-1 5.0 - 8.0 SC 8.3 809 1321 467 2

CMP-2 5.0 - 8.0 SC 8.3 968 240 357 2

50pH Resistivity

(ohm-cm)Sulfates(ppm)

Chlorides(ppm)

DryDensity

(pcf)

Expansion(%)

Corrosivity

Dry Density(pcf)

Atterberg Limits

In-Situ Properties

Passing#200

Sieve (%)

Classification

PL PI

WaterContent

(%)

Remarks

Expansion Testing

Surcharge(psf)

WaterContent (%) LL

USCSSoil

Class.Expansion

IndexEI

REMARKS1. Dry Density and/or moisture determined from one or more rings of a multi-ring sample.2. Visual Classification.3. Submerged to approximate saturation.4. Expansion Index in accordance with ASTM D4829-95.5. Air-Dried Sample

BoreholeNo.

Depth(ft.)

SUMMARY OF LABORATORY RESULTS

PROJECT: Proposed San Tan Valley Administration Complex PROJECT NUMBER: 65185202



PH. 480-897-8200 FAX. 480-897-1133


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

SO

IL P

RO

PE

RT

IES

2 6

518

520

2 P

RO

PO

SE

D P

INA

L C

O -

CO

PY

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/21/

19

Geotechnical Engineering Report...Our geotechnical engineering scope of work for this project...

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Transcript of Geotechnical Engineering Report...Our geotechnical engineering scope of work for this project...