geotechnical engineering report...geotechnical engineering report queens road sdip – phase ii...

Geotechnical Engineering ReportQueens Road Storm Drainage Improvement Project – Phase II

Charlotte, North CarolinaMarch 17, 2017

Project No. 71175007

Prepared for:Dewberry

Charlotte, North Carolina

Prepared by:Terracon Consultants, Inc.

Charlotte, North Carolina

Responsive ■ Resourceful ■ Reliable

TABLE OF CONTENTSPage

EXECUTIVE SUMMARY ............................................................................................................. i1.0 INTRODUCTION ............................................................................................................. 12.0 PROJECT INFORMATION ............................................................................................. 1

2.1 Site Location and Description............................................................................... 12.2 Project Description ............................................................................................... 2

3.0 SUBSURFACE CONDITIONS ........................................................................................ 23.1 Geology ............................................................................................................... 23.2 Typical Profile ...................................................................................................... 33.3 Groundwater ........................................................................................................ 3

4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ...................................... 44.1 Geotechnical Considerations ............................................................................... 44.2 Earthwork............................................................................................................. 5

4.2.1 Compaction Requirements ....................................................................... 54.2.2 Material Types .......................................................................................... 54.2.3 Earthwork Construction Considerations .................................................... 64.2.4 Excavations .............................................................................................. 6

4.3 Groundwater Considerations................................................................................ 74.4 Foundations ......................................................................................................... 7

4.4.1 Foundation Design Recommendations ..................................................... 74.4.2 Foundation Construction Considerations .................................................. 8

4.5 Lateral Earth Pressures ....................................................................................... 85.0 GENERAL COMMENTS ............................................................................................... 10

APPENDIX A – FIELD EXPLORATIONExhibits A-1a & A-1b Site LocationExhibits A-2a & A-2b Exploration PlanExhibit A-3 Field Exploration DescriptionExhibits A-4 to A-10 Boring Logs

APPENDIX B – LABORATORY TESTINGExhibit B-1 Laboratory Testing

APPENDIX C – SUPPORTING DOCUMENTSExhibit C-1 General NotesExhibit C-2 Unified Soil Classification System

Geotechnical Engineering ReportQueens Road SDIP – Phase II ■ Charlotte, North CarolinaMarch 17, 2017 ■ Terracon Project No. 71175007

Responsive ■ Resourceful ■ Reliable i

EXECUTIVE SUMMARY

A geotechnical investigation has been performed along the alignment of the proposed QueensRoad Storm Drainage Improvement project located in Charlotte, North Carolina. Seven borings,designated HA-1 and B-2 through B-7, were performed to depths of approximately 7 to 15 feetbelow the existing ground surface along the alignment of the proposed storm sewer line.

Based on the information obtained from our subsurface exploration, the site can be developed forthe proposed project. The following geotechnical considerations were identified:

n Based on the estimated bottom of excavation depths we anticipate that groundwater will beencountered during construction in portions of this project. The need for dewatering duringconstruction should be anticipated by the contractor.

n The residual, alluvial and fill soils encountered along the alignment may be excavatedwith the use of conventional construction equipment, such as bulldozers, backhoes,and trackhoes.

n Medium to high plasticity soils were identified in most of the borings, and may be presentin other areas of the site between our boring locations. These soils can be moisturesensitive and difficult to work. These difficulties can include the inability to adequately dryand compact. We recommend that the contractor be requested to submit a unit rate costfor removal and replacement as part of the bidding process.

n Headwall and wing wall structures may be supported on conventional spread and stripfootings with net allowable bearing pressures of 2,000 psf.

This summary should be used in conjunction with the entire report for design purposes. Itshould be recognized that details were not included or fully developed in this section, and thereport must be read in its entirety for a comprehensive understanding of the items containedherein. The section titled GENERAL COMMENTS should be read for an understanding of thereport limitations.

Responsive ■ Resourceful ■ Reliable 1

GEOTECHNICAL ENGINEERING REPORTQUEENS ROAD STORM DRAINAGE IMPROVEMENT PROJECT

PHASE IICHARLOTTE, NORTH CAROLINA

Project No. 71175007March 17, 2017

1.0 INTRODUCTION

A geotechnical investigation has been performed along the alignment of the proposed QueensRoad Storm Drainage Improvement project located in Charlotte, North Carolina. Seven borings,designated HA-1 and B-2 through B-7, were performed to depths of approximately 7 to 15 feetbelow the existing ground surface along the alignment of the proposed storm sewer line. Logs ofthe borings, along with Site Location and Exploration Plan exhibits, are included in Appendix A ofthis report.

The purpose of these services is to provide information and geotechnical engineeringrecommendations relative to:

n Subsurface soil conditionsn Earthworkn Lateral earth pressures

n Groundwater conditionsn Difficult excavationn Shallow foundations

2.0 PROJECT INFORMATION

2.1 Site Location and Description

ITEM DESCRIPTION

Location The site is located on along Baxter Street and Queens Road inCharlotte, NC.

Existing development The site is situated along existing asphalt roads within a residentialneighborhood.

Current ground cover Asphalt, grass and shrubs.

Existing topography

Based on the provided plans, the elevations along the proposedstorm drain alignment vary from a high elevation of about 673 feetnear the intersection of Queens Road and Baxter Street, to a lowelevation of about 650 feet near the proposed new storm water outfallstructure.



2.2 Project Description

ITEM DESCRIPTION

Structures

The project will consist of installing a new storm water pipe alongBaxter Street, which will connect into an existing structure withinthe Queens Road median. The new pipe will vary in depthbetween about 6 and 13 feet below existing grades. A new boxstructure is proposed near the end of the new alignment, and anew outfall structure will be constructed consisting of a headwalland wing walls.

Grading We estimate that finished grades will be close to existing grades.

3.0 SUBSURFACE CONDITIONS

3.1 Geology

The project site is located in the Piedmont Physiographic Province, an area underlain by ancientigneous and metamorphic rocks. The residual soils in this area are the product of in-placechemical weathering of rock. The typical residual soil profile consists of clayey soils near thesurface where soil weathering is more advanced, underlain by sandy silts and silty sands thatgenerally become harder with depth to the top of parent bedrock. Alluvial soils are typicallypresent within floodplain areas along creeks and rivers in the Piedmont. According to the 1985Geologic Map of North Carolina, the site is within the Charlotte Belt. The bedrock underlying thesite generally consists of granitic rock.

The boundary between soil and rock in the Piedmont is not sharply defined. A transitional zonetermed “partially weathered rock” is normally found overlying the parent bedrock. Partiallyweathered rock is defined for engineering purposes as residual material with standardpenetration test resistance’s exceeding 100 blows per foot. The transition between hard/denseresidual soils and partially weathered rock occurs at irregular depths due to variations in degreeof weathering.

Groundwater is typically present in fractures within the partially weathered rock or underlyingbedrock in the Piedmont. Fluctuations in groundwater levels on the order of 2 to 4 feet are typicalin residual soils and partially weathered rock in the Piedmont, depending on variations inprecipitation, evaporation, and surface water runoff. Seasonal high groundwater levels areexpected to occur during or just after the typically cooler months of the year (November throughApril).



3.2 Typical Profile

Based on the results of the borings, subsurface conditions on the project site can begeneralized as follows:

Boring No.Approx.

Elevation 1

(feet)

Boring Depth 2

(feet)

Water TableDepth 2

(feet)PWR Depth2

(feet)Refusal Depth2

(feet)

HA-1 651 7 3 NE NE

B-2 656 15 10 NE NE

B-3 659 15 12 NE NE

B-4 660.5 10 8.1 NE NE

B-5 662 10 NE NE NE

B-6 664.5 15 11.3 NE NE

B-7 671.5 15 NE NE NENotes: 1. Existing surface elevations approximated from “Queens Rd. Phase II Storm Drainage

Repair Project – Option 3,” dated 11/07/2016.2. Depths referenced from the existing ground surface.NE: Not Encountered

Conditions encountered at each boring location are indicated on the individual boring logs.Stratification boundaries on the boring logs represent the approximate location of changes insoil types; in situ, the transition between materials may be gradual. Details for each of theborings can be found on the boring logs in Appendix A of this report.

3.3 Groundwater

The boreholes were observed while drilling and after completion for the presence and level ofgroundwater. Groundwater was observed from approximately 3 to 12 feet below existing gradesin 5 of 7 borings during the relatively short amount of time they were left open after drilling / handaugering. Each of the borings were backfilled with auger cuttings after completion, makingsubsequent water level readings unobtainable.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoffand other factors not evident at the time the borings were performed. Therefore, groundwaterlevels during construction or at other times in the life of the structure may be higher or lowerthan the levels indicated on the boring logs. The possibility of groundwater level fluctuationsshould be considered when developing the design and construction plans for the project.



4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION

4.1 Geotechnical Considerations

Our evaluation and recommendations are based on the project information outlined previouslyand on the data obtained from the field testing program. If project plans are changedsignificantly, Terracon requests the opportunity to review our recommendations based on thenew information and make necessary changes.

The residual, alluvial and fill soils encountered along the alignment may be excavated with theuse of conventional construction equipment, such as bulldozers, backhoes, and trackhoes.

A geotechnical concern for this site is the undocumented fill soils encountered in the borings.Some of the existing fill appears to have been placed with little compactive effort.

Medium to high plasticity soils were identified in most of the borings. These soils can be moisturesensitive and difficult to work. These difficulties can include the inability to adequately dry andcompact. It may become difficult to reuse these soils as properly compacted trench backfillmaterials without significant effort. We recommend that the contractor be requested to submit aunit rate cost for removal and replacement as part of the bidding process Additional detailsregarding use of moderate plasticity soils is included in the Earthwork Section of this report.

Relatively soft soils (SPT N-Values / DCP values less than 5 blows-per-foot / blows-per-increment) were present in each of the borings to depths up to about 5 to 12 feet below existinggrades. If these soft soils are encountered at proposed pipe invert elevations, the subgrade mayneed to be undercut approximately 1 to 2 feet and backfilled to grade with suitable fill material toavoid problems with differential settlement at pipe joints. We recommend that the contractor berequested to submit a unit rate cost for undercutting as part of the bidding process.

Based on the results of our subsurface exploration, it is our opinion that the proposedheadwall and wing wall structures may be supported on conventional spread and strip footingswith net allowable bearing pressures of 2,000 psf.

Groundwater was observed at depths of approximately 3 to 12 feet below existing grades inborings HA-1, B-2, B-3, B-4, and B-6 during the relatively short amount of time the boringsremained open after drilling and hand augering. Based on the estimated depth of the proposedstorm sewer line, we anticipate that groundwater may be a factor along the storm sewer linealignment, and that temporary dewatering will be required.

Due to the depth of the water table encountered, some of the soils encountered at or abovethe proposed storm sewer elevation will likely be wet during construction. Reusing these soilsas structural fill will likely require drying to reach optimum moisture, and may lead to



significant delays during construction. Depending on the time of year construction takes place,and the time it will take to dry the on-site soil, replacement of the on-site soils with importedstructural fill may be more economical. We recommend that the contractor submit a unit ratefor removal and replacement of the on-site soils as part of the bidding process.

4.2 Earthwork

Our evaluation and recommendations are based on the project information outlined previouslyand on the data obtained from the field testing program. If project plans are changedsignificantly, Terracon requests the opportunity to review our recommendations based on thenew information and make necessary changes.

4.2.1 Compaction RequirementsWe recommend that engineered fill be tested for moisture content and compaction duringplacement. Should the results of the in-place density tests indicate the specified moisture orcompaction limits have not been met, the area represented by the test should be reworkedand retested as required until the specified moisture and compaction requirements areachieved.

Engineered fill should meet the following compaction requirements:

ITEM DESCRIPTION

Fill Lift Thickness

8 to 10 inches or less in loose thickness when heavy, self-propelled compaction equipment is used.4 to 6 inches in loose thickness when hand-guided equipment (e.g.jumping jack or plate compactor) is used.

Compaction Requirements

Minimum 95% of the material’s maximum standard Proctor drydensity (ASTM D 698)The upper 12 inches in pavement areas should be compacted to atleast 100% of the materials maximum standard Proctor dry density(ASTM D 698)

Moisture ContentRequirements

Within 3% of the optimum moisture content value as determined bythe standard Proctor test at the time of placement and compaction

4.2.2 Material TypesThe low to medium-plasticity natural and fill soils encountered in our borings appear to besuitable for re-use as engineered fill.

Engineered fill should meet the following material property requirements:



Fill Type 1 USCSClassification Acceptable Location for Placement

On-Site Low toModerate Plasticity

Soils

SM, SC, MH, andML

(LL<60 & PI<30)All locations and elevations.

Imported LowPlasticity Soils

SM, SC, CL, ML(LL<50 & PI<20)

All locations and elevations.

1. Controlled, compacted fill should consist of approved materials that are free of organic matter anddebris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. Asample of each material type should be submitted to the geotechnical engineer for evaluation.

4.2.3 Earthwork Construction ConsiderationsUnstable subgrade conditions could develop during general construction operations, particularly ifthe soils are wetted and/or subjected to repetitive construction traffic. The use of lightconstruction equipment would aid in reducing subgrade disturbance. Should unstable subgradeconditions develop, stabilization measures will need to be employed.

Upon completion of filling and grading, care should be taken to maintain the subgrademoisture content prior to construction of pavements. Construction traffic over the completedsubgrade should be avoided to the extent practical. If the subgrade should become frozen,desiccated, saturated, or disturbed, the affected material should be removed or thesematerials should be scarified, moisture conditioned, and recompacted prior to pavementconstruction.

If subgrade soils are unsuitable, such as elastic silts and fat clays, they will require removaland replacement with either approved engineered fill or aggregate base course (ABC) stone.We recommend that the contractor submit a unit rate cost for undercutting as part of thebidding process.

The geotechnical engineer should be retained during the construction phase of the project toobserve construction and to perform necessary tests and observations during subgradepreparation.

4.2.4 ExcavationsThe residual, alluvial and fill soils encountered along the alignment may be excavated with theuse of conventional construction equipment, such as bulldozers, backhoes, and trackhoes.

All temporary excavations should be sloped or braced as required by Occupational Safety andHealth Administration (OSHA) regulations to provide stability and safe working conditions.Temporary excavations will probably be required during grading operations. The gradingcontractor is often responsible for designing and constructing stable, temporary excavationsand should shore, slope or bench the sides of the excavations as required, to maintain stability



of both the excavation sides and bottom. All excavations should comply with applicable local,state and federal safety regulations, including the current OSHA Excavation and Trench SafetyStandards.

4.3 Groundwater Considerations

Because the pipe invert elevations and bearing elevation of the drainage structures may bebelow the groundwater level at locations near HA-1, B-2, B-3, B-4, and B-6, there is a potentialfor the groundwater to rise above the bearing elevation and into the excavation duringconstruction. Additionally, water may be encountered in areas between our boring locations. Assuch, appropriate dewatering measures should be anticipated during construction and theexcavation should be opened for a minimal length of time. During construction, it isrecommended that the water level be kept below the bottom of the proposed pipe elevations.

Additionally, buoyant forces which can occur from a rising water table level should be consideredduring both design and construction of the pipes and drainage structures, especially prior tocompletion of the placement of the overlying fill material.

4.4 Foundations

In our opinion, the proposed outfall structures can be supported by shallow, spread footingfoundation systems bearing within suitable existing fill, residual soils or new properlycompacted fill. Design recommendations for shallow foundations for the proposed structureare presented in the following sections.

4.4.1 Foundation Design Recommendations

DESCRIPTION Strip Footing

Net allowable bearing pressure 1 2,000 psf

Minimum dimensions 18 inches

Minimum embedment below finished grade 18 inches

Approximate total / differential settlement 2 < 3/4 inch over 40 feet

Ultimate coefficient of sliding friction 0.30

1. The recommended net allowable bearing pressure is the pressure in excess of the minimumsurrounding overburden pressure at the footing base elevation. Assumes any fill or soft soils, ifencountered, will be undercut and replaced with engineered fill.

2. The foundation settlement will depend upon the variations within the subsurface soil profile, thestructural loading conditions, the embedment depth of the footings, the thickness of compactedfill, and the quality of the earthwork operations.

The allowable foundation bearing pressures apply to dead loads plus design live loadconditions. The design bearing pressure may be increased by one-third when considering total



loads that include wind or seismic conditions. The weight of the foundation concrete belowgrade may be neglected in dead load computations. Interior footings should bear a minimumof 12 inches below finished grade. Finished grade is the lowest adjacent grade for perimeterfootings and floor level for interior footings.

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

4.4.2 Foundation Construction ConsiderationsThe foundation bearing materials should be evaluated at the time of the foundationexcavation. A representative of Terracon should use a combination of hand auger borings anddynamic cone penetrometer (DCP) testing in conjunction with visual observations to determinethe suitability of the bearing materials for the design bearing pressure.

The base of all foundation excavations should be free of water and loose soil and rock prior toplacing concrete. Concrete should be placed soon after excavating to reduce bearing soildisturbance. Should the soils at bearing level become disturbed, saturated, or frozen, theaffected soil should be removed prior to placing concrete. Exposure to inclement weather canintroduce unwanted moisture into the footing subgrade. If construction occurs during inclementweather, and concreting of foundations is not possible at the time they are excavated, a layerof lean concrete should be placed on exposed bearing surfaces for protection. Where highmoisture conditions are encountered at footing bearing elevations, the bottom of theexcavations could be stabilized with a relatively clean, well-graded crushed stone or gravel, ora lean concrete mud mat to provide a working base for construction.

4.5 Lateral Earth Pressures

The following section specifies the lateral earth pressure coefficients to be used for the designof wing walls, temporary shoring for foundations and trenches.

Shoring for foundations and trenches with unbalanced backfill levels on opposite sides shouldbe designed for earth pressures at least equal to those indicated in the following table. Earthpressures will be influenced by structural design of shoring, methods of construction and/orcompaction and the strength of the materials being restrained. Two wall restraint conditions areshown. Active earth pressure is commonly used for design of free-standing cantilever retainingwalls and assumes wall movement. The "at-rest" condition assumes no wall movement. Therecommended design lateral earth pressures do not include a factor of safety and do notprovide for possible hydrostatic pressure on the walls.



Earth Pressure CoefficientsEarth

PressureConditions

Earth Pressure Coefficientfor Existing Soil Type

EquivalentFluid Density

(pcf)

SurchargePressure,

p1 (psf)

EarthPressure, p2

(psf)

Active (Ka) On-site clayey sand (SC) andsandy silt (ML) - 0.39 43 (0.39)S (43)H1 + (22)H2

At-Rest(Ko)

On-site clayey sand (SC) andsandy silt (ML) - 0.56 62 (0.56)S (62)H1 + (32)H2

Passive(Kp)

On-site clayey sand (SC) andsandy silt (ML) – 2.56 282 --- ---

Applicable conditions to the above include:

n For active earth pressure, wall must rotate about base, with top lateral movements ofabout 0.002 H to 0.004 H, where H is wall height

n For passive earth pressure to develop, wall must move horizontally to mobilize resistancen Uniform surcharge, where S is surcharge pressuren In-situ existing silt unit weight assumed to be a maximum of 110 pcfn Unit weight of water (ɣw) is 62.4 pcfn Horizontal backfill, compacted to 95 percent of standard Proctor maximum dry densityn Loading from heavy compaction equipment should be included as “S”n No dynamic loadingn No safety factor includedn Ignore passive pressure in frost zone



5.0 GENERAL COMMENTS

Terracon should be retained to review the final design plans and specifications so commentscan be made regarding interpretation and implementation of our geotechnical recommendationsin the design and specifications. Terracon also should be retained to provide observation andtesting services during grading, excavation, foundation construction and other earth-relatedconstruction phases of the project.

The analysis and recommendations presented in this report are based upon the data obtainedfrom the borings performed at the indicated locations and from other information discussed inthis report. This report does not reflect variations that may occur between borings, across thesite, or due to the modifying effects of construction or weather. The nature and extent of suchvariations may not become evident until during or after construction. If variations appear, weshould be immediately notified so that further evaluation and supplemental recommendationscan be provided.

The scope of services for this project does not include either specifically or by implication anyenvironmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification orprevention of pollutants, hazardous materials or conditions. If the owner is concerned about thepotential for such contamination or pollution, other studies should be undertaken.

This report has been prepared for the exclusive use of our client for specific application to theproject discussed and has been prepared in accordance with generally accepted geotechnicalengineering practices. No warranties, either express or implied, are intended or made. Sitesafety, excavation support, and dewatering requirements are the responsibility of others. In theevent that changes in the nature, design, or location of the project as outlined in this report areplanned, the conclusions and recommendations contained in this report shall not be consideredvalid unless Terracon reviews the changes and either verifies or modifies the conclusions of thisreport in writing.

APPENDIX A

FIELD EXPLORATION

TOPOGRAPHIC MAP IMAGE COURTESY OFTHE U.S. GEOLOGICAL SURVEY

QUADRANGLES INCLUDE: CHARLOTTEEAST, NC (1/1/1988).

SITE LOCATION

Queens Road SDIP - Phase IIBaxter Street at Queens Road

Charlotte, NC2020 Starita Rd Ste E

Charlotte, NC 28206-1298

71175007

DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION

PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

RCG

CRB

DJC

CRB

A1-A2

3/17/2017

Project No.

File Name:

Date:

A-1a

Exhibit

SITE

1”=2,000’Scale:

SITE LOCATION




71175007


PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

RCG

CRB

DJC

CRB

A1-A2

3/17/2017

Project No.

File Name:

Date:

A-1b

Exhibit

SITE

AS SHOWNScale:MAP IMAGE PROVIDED BY GOOGLE

MAPS

EXPLORATION PLAN




71175007


PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

RCG

CRB

DJC

CRB

A1-A2

3/17/2017

Project No.

File Name:

Date:

A-2a

Exhibit

AS SHOWNScale:

AERIAL PHOTOGRAPHY PROVIDED BYMICROSOFT BING MAPS

AERIAL PHOTOGRAPHY PROVIDED BYGOOGLE EARTH

EXPLORATION PLAN

2020 Starita Rd Ste ECharlotte, NC 28206-1298

71175007


Charlotte, NCDIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION

PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

RCG

CRB

DJC

CRB

A1-A2

3/17/2017

Scale:

Project No.

File Name:

Date:

AS SHOWN A-2b

Exhibit


Exhibit A-3Responsive ■ Resourceful ■ Reliable

Field Exploration DescriptionThe boring locations were laid out on the site by Terracon personnel utilizing a site plan providedand were measured from existing features. The locations of the borings should be consideredaccurate only to the degree implied by the means and methods used to define them.

The borings were drilled with an ATV-mounted rotary drill rig using hollow stem augers toadvance the boreholes. Samples of the soil encountered in the borings were obtained using thesplit-barrel sampling procedure.

In the split barrel sampling procedure, the number of blows required to advance a standard 2inch O.D. split barrel sampler the last 12 inches of the typical total 18 inch penetration bymeans of a 140 pound hammer with a free fall of 30 inches, is the standard penetrationresistance value (SPT-N). This value is used to estimate the in-situ relative density ofcohesionless soils and consistency of cohesive soils.

An automatic SPT hammer and a 140lb Slide hammer were used to advance the split-barrelsampler in the borings performed on this site. A significantly greater efficiency is achievedwith the automatic hammer compared to the conventional safety hammer operated with acathead and rope. This higher efficiency has an appreciable effect on the SPT-N value.

The samples were tagged for identification, sealed to reduce moisture loss, and taken to ourlaboratory for further examination, testing, and classification. Information provided on the boringlogs attached to this report includes soil descriptions, consistency evaluations, boring depths,sampling intervals, and groundwater conditions. The borings were backfilled with auger cuttingsprior to the drill crew leaving the site.

A field log of each boring was prepared by the field professional. These logs included visualclassifications of the materials encountered during drilling as well as the field professional’sinterpretation of the subsurface conditions between samples. Final boring logs included with thisreport represent the engineer's interpretation of the field logs and include modifications based onlaboratory observation and tests of the samples.

DCP = 3(3-3-3)

DCP = 1(2-2-1)

DCP = 14(9-15-13)

DCP = 6(5-5-8)

DCP = 9(13-9-9)

DCP = 9(11-9-10)

DCP = 13(12-14-13)

2.0

3.0

7.0

FILL - ELASTIC SILT (MH), trace sand, trace mica from 1' to 2',brown

SANDY SILT (ML), brown with tan and white, residuum

SANDY ELASTIC SILT (MH), saturated, brown, residuum

Boring Terminated at 7 Feet

28649+/-

648+/-

644+/-

GR

AP

HIC

LO

G

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

TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

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PA

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117

500

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LAT

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DEPTH

LOCATION See Exhibit A-2

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)

Approximate Surface Elev: 651 (Ft.) +/-

SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

RE

CO

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RY

(In

.)

Baxter Street and Queens Road Charlotte, NCSITE:

Page 1 of 1

Advancement Method:Hand Auger

Abandonment Method:Backfilled with Auger Cuttings

Notes:

Project No.: 71175007

Drill Rig:

Boring Started: 3/2/2017

BORING LOG NO. HA-1Dewberry Engineers, Inc.CLIENT:6135 Lakeview Road

Driller:

Boring Completed: 3/2/2017

Exhibit: A-4

See Exhibit A-3 for description of fieldprocedures.See Appendix B for description of laboratoryprocedures and additional data (if any).

See Appendix C for explanation of symbols andabbreviations.Elevations approximated from informationprovided by Dewberry.

PROJECT: Queens Road SDIP Phase 2

2020 Starita Rd Ste ECharlotte, NCWet Cave-In

While hand augering

Wet Cave-In

WATER LEVEL OBSERVATIONSWhile hand augering

2-3-2N=5

2-1-2N=3

2-1-1N=2

2-2-3N=5

3-3-5N=8

0.3

4.8

8.0

9.2

15.0

4" TOPSOILFILL - ELASTIC SILT (MH), trace sand, trace mica, trace gravel, grayand red, soft to medium-stiff

CLAYEY SAND (SC), gray and brownish red, very loose, possiblealluvium

SILT (ML), trace sand, dark blue, medium-stiff, residuum

SILT WITH SAND (ML), trace mica, white and tan, medium-stiff tostiff, residuum


4816 29-17-12

655.5+/-

651+/-

648+/-

647+/-

641+/-

18

18

11

18

13

GR

AP

HIC

LO

G

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

TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

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T.

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SM

AR

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-NO

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LL 7

117

500

7 -

QU

EE

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RD

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2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

RE

CO

VE

RY

(In

.)


Page 1 of 1

Advancement Method:4" Hollow Stem Auger


Notes:


Drill Rig: CME-550


BORING LOG NO. B-2Dewberry Engineers, Inc.CLIENT:6135 Lakeview Road

Driller: HPC


Exhibit: A-5





After drilling

Wet Cave-In

WATER LEVEL OBSERVATIONSAfter drilling

0-3-1N=4

2-1-2N=3

2-3-5N=8

7-6-5N=11

8-11-13N=24

0.3

6.0

7.5

15.0

3" TOPSOILFILL - SILT (ML), trace sand, with organics from 3.5' to 5', brown andtan to red, brown and black, soft to medium-stiff

NO RECOVERY

SILTY SAND (SM), tan, white and brown to brown and tan,medium-dense, residuum


17

658.5+/-

653+/-

651.5+/-

644+/-

18

13

0

18

18

GR

AP

HIC

LO

G


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.

G

EO

SM

AR

T L

OG

-NO

WE

LL 7

117

500

7 -

QU

EE

NS

RD

PH

2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

RE

CO

VE

RY

(In

.)


Page 1 of 1



Notes:


Drill Rig: CME-550



Driller: HPC


Exhibit: A-6





After drilling

Wet Cave-In


2-1-2N=3

3-2-3N=5

0-1-2N=3

2-4-3N=7

0.4

1.2

3.1

5.5

8.0

10.0

5" ASPHALT9" STONE

FILL - SANDY ELASTIC SILT (MH), red to gray and red, soft

FILL - CLAYEY SAND (SC), gray, loose

SILT (ML), trace sand, trace mica, trace gravel, reddish brown andwhite, soft, residuum

SILT WITH SAND (ML), reddish brown, white and black,medium-stiff, residuum


4515 28-16-12

660+/-

659.5+/-

657.5+/-

655+/-

652.5+/-

650.5+/-

18

3

18

18

GR

AP

HIC

LO

G


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.

G

EO

SM

AR

T L

OG

-NO

WE

LL 7

117

500

7 -

QU

EE

NS

RD

PH

2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)

Approximate Surface Elev: 660.5 (Ft.) +/-

SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

RE

CO

VE

RY

(In

.)


Page 1 of 1



Notes:


Drill Rig: CME-550



Driller: HPC


Exhibit: A-7





After drilling

Wet Cave-In


3-2-3N=5

3-4-7N=11

3-2-3N=5

3-4-5N=9

0.3

0.9

3.0

7.2

10.0

4" ASPHALT7" STONE

FILL - SILTY SAND (SM), red and brown, loose

FILL - SANDY ELASTIC SILT (MH), trace gravel from 6' to 7.2', graywith tan, medium-stiff to stiff

SILT (ML), trace sand, trace mica, brown, stiff, residuum


19

661.5+/-

661+/-

659+/-

655+/-

652+/-

18

18

18

18

GR

AP

HIC

LO

G


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.

G

EO

SM

AR

T L

OG

-NO

WE

LL 7

117

500

7 -

QU

EE

NS

RD

PH

2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

RE

CO

VE

RY

(In

.)


Page 1 of 1



Notes:


Drill Rig: CME-550



Driller: HPC


Exhibit: A-8




2020 Starita Rd Ste ECharlotte, NCDry Cave-InDry Cave-In

WATER LEVEL OBSERVATIONSNo free water observed

3-2-3N=5

0-0-1N=1

3-3-3N=6

0-2-2N=4

5-9-12N=21

0.3

1.3

3.2

6.0

8.7

15.0

4" ASPHALT12" STONE

FILL - SILT (ML), trace sand, brown, medium-stiff

FILL - SANDY ELASTIC SILT (MH), tannish gray and red, very soft

FILL - CLAYEY SAND (SC), gray and red, loose

SILT WITH SAND (ML), trace mica from 13.5' to 15', blue, white andtan to brown, very stiff, residuum


27

664+/-

663+/-

661.5+/-

658.5+/-

656+/-

649.5+/-

18

18

18

18

18

GR

AP

HIC

LO

G


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.

G

EO

SM

AR

T L

OG

-NO

WE

LL 7

117

500

7 -

QU

EE

NS

RD

PH

2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

RE

CO

VE

RY

(In

.)


Page 1 of 1



Notes:


Drill Rig: CME-550



Driller: HPC


Exhibit: A-9





After drilling

Wet Cave-In


3-2-3N=5

1-2-2N=4

3-2-3N=5

3-3-3N=6

4-8-9N=17

0.3

3.0

5.5

8.0

12.0

15.0

3" TOPSOILFILL - SILT WITH SAND (ML), red, medium-stiff

FILL - SILT (ML), trace sand, trace mica, red, soft to medium-stiff

FILL - CLAYEY SAND (SC), dark red and reddish brown, loose

FILL - SANDY ELASTIC SILT (MH), trace roots, tan, brown and gray,medium-stiff

SILTY SAND WITH GRAVEL (SM), white, tan and brown,medium-dense, residuum


5323 57-33-24

671+/-

668.5+/-

666+/-

663.5+/-

659.5+/-

656.5+/-

18

12

18

18

13

GR

AP

HIC

LO

G


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.

G

EO

SM

AR

T L

OG

-NO

WE

LL 7

117

500

7 -

QU

EE

NS

RD

PH

2.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/1

6/1

7

FIE

LD T

ES

TR

ES

ULT

S

DEPTH


PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


SA

MP

LE T

YP

E

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

RE

CO

VE

RY

(In

.)


Page 1 of 1



Notes:


Drill Rig: CME-550



Driller: HPC


Exhibit: A-10




2020 Starita Rd Ste ECharlotte, NCDry Cave-InDry Cave-In

WATER LEVEL OBSERVATIONSNo free water observed

APPENDIX B

LABORATORY TESTING

Geotechnical Engineering Report - DraftQueens Road SDIP – Phase II ■ Charlotte, North CarolinaMarch 17, 2017 ■ Terracon Project No. 71175007

Responsive ■ Resourceful ■ Reliable Exhibit B-1

Laboratory Testing Description and Results

The following laboratory tests were performed on select soil samples for this project: in-situmoisture content, Atterberg Limits and wash no. 200 sieve tests. The results of these tests aresummarized in the following tables. Laboratory test results are also shown on the boring logs atthe sample.

The following table summarizes the in-situ moisture content, wash No. 200 sieve tests, andAtterberg Limits test results. These results are also shown on the boring logs in Appendix A.

Sample Location,Depth

In-situMoisture

Content (%)

% Passingthe No.

200 Sieve

Liquid Limit,(%)

PlasticLimit, (%)

PlasticityIndex, (%)

HA-01, 2’ – 2.4’ 27.6 - - - -B-02, 6’ – 7.5’ 16.3 48.2 29 17 12

B-03, 8.5’ – 10’ 17.2 - - - -B-04, 3.5’ – 5’ 15.2 44.9 28 16 12B-05, 1’ – 2.5’ 19.1 - - - -B-06, 3.5’ – 5’ 27.4 - - - -

B-07, 8.5’ – 10’ 23.4 53.2 57 33 24

APPENDIX C

SUPPORTING DOCUMENTS

Exhibit: C-1

Unconfined Compressive StrengthQu, (psf)

500 to 1,000

2,000 to 4,000

4,000 to 8,000

1,000 to 2,000

less than 500

> 8,000

DynamicConePenetrometer

StandardPenetrationTest

Non-plasticLowMediumHigh

DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

GENERAL NOTES

Over 12 in. (300 mm)12 in. to 3 in. (300mm to 75mm)3 in. to #4 sieve (75mm to 4.75 mm)#4 to #200 sieve (4.75mm to 0.075mmPassing #200 sieve (0.075mm)

Particle Size

< 55 - 12> 12

Percent ofDry Weight

Descriptive Term(s)of other constituents

RELATIVE PROPORTIONS OF FINES

01 - 1011 - 30

> 30

Plasticity Index

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

LOCATION AND ELEVATION NOTES

Percent ofDry Weight

Major Componentof Sample

TraceWithModifier

RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY

TraceWithModifier

DESCRIPTIVE SOIL CLASSIFICATION

BouldersCobblesGravelSandSilt or Clay

Descriptive Term(s)of other constituents

< 1515 - 29> 30

Term

PLASTICITY DESCRIPTION

Water levels indicated on the soil boringlogs are the levels measured in theborehole at the times indicated.Groundwater level variations will occurover time. In low permeability soils,accurate determination of groundwaterlevels is not possible with short termwater level observations.

Water Level Aftera Specified Period of Time

Water Level After aSpecified Period of Time

Water InitiallyEncountered

Standard Penetration TestResistance (Blows/Ft.)

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Photo-Ionization Detector

Organic Vapor Analyzer

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracyof such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey wasconducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographicmaps of the area.

N

(HP)

(T)

(DCP)

(PID)

(OVA)

FIE

LD

TE

ST

S

WA

TE

R L

EV

EL

SA

MP

LIN

GS

TR

EN

GT

H T

ER

MS Standard Penetration or

N-ValueBlows/Ft.

Descriptive Term(Consistency)

Descriptive Term(Density)

CONSISTENCY OF FINE-GRAINED SOILS

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

visual-manual procedures or standard penetration resistance

Standard Penetration orN-Value

Blows/Ft.

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

RELATIVE DENSITY OF COARSE-GRAINED SOILS

Hard > 30

> 50 15 - 30Very Stiff

Stiff

Medium Stiff

Very Soft 0 - 1

Medium Dense

SoftLoose

Very Dense

8 - 1530 - 50Dense

4 - 810 - 29

2 - 44 - 9

Very Loose 0 - 3

Exhibit C-2

UNIFIED SOIL CLASSIFICATION SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A

Soil ClassificationGroupSymb

olGroup Name B

Coarse Grained Soils:More than 50%retained on No. 200sieve

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

Clean Gravels:Less than 5% fines C

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

Cu < 4 and/or 1 > Cc > 3 E GP Poorly graded gravel F

Gravels with Fines:More than 12% finesC

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 ofcoarse fraction passesNo. 4 sieve

Clean Sands:Less than 5% fines D

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

Cu < 6 and/or 1 > Cc > 3 E SP Poorly graded sand I

Sands with Fines:More than 12% finesD

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 passesthe No. 200 sieve

Silts and Clays:Liquid limit less than50

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

CL Lean clay K,L,M

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

Organic:Liquid limit - ovendried < 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 - ovendried < 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 Peat

A Based on the material passing the 3-in. (75-mm) sieveB 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.M If soil contains ³ 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.N PI ³ 4 and plots on or above “A” line.O PI < 4 or plots below “A” line.P PI plots on or above “A” line.Q PI plots below “A” line.

geotechnical engineering report...geotechnical engineering report queens road sdip – phase ii...

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