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SUBSURFACE EXPLORATION AND GEOTECHNICAL EVALUATION

PROPOSED KEESEE MULTIFAMILY DEVELOPMENT 10413 INTERSTATE HIGHWAY 35 SOUTH

AUSTIN, TEXAS

ECS PROJECT NO.: 17-4312

FOR

ARDENT RESIDENTIAL, L.P.

JULY 27, 2015

2120 Denton Drive, Suite 105, Austin, TX 78758 • T: 512-837-8005 • F: 512-837-8221 • www.ecslimited.com

ECS Carolinas, LLP • ECS Florida, LLC • ECS Midwest, LLC • ECS Mid-Atlantic, LLC • ECS Southeast, LLC • ECS Texas, LLP

July 27, 2015

Mr. Art Carpenter Ardent Residential, L.P. 5453 Burnet Road, Suite 203 Austin, Texas 78756

ECS Project No. 17-4312

Subject: Subsurface Exploration and Geotechnical Evaluation Proposed Keesee Multifamily Development 10413 Interstate Highway 35 South Austin, Texas

Dear Mr. Carpenter:

We have completed our subsurface exploration and geotechnical engineering evaluation for the above-referenced project. Our geotechnical design and construction recommendations for the proposed development are presented in this report.

We appreciate the opportunity to serve as your geotechnical consultant and look forward to the opportunity to work with you through the design and construction of this project. Should you have any questions, comments, or concerns regarding this report, please contact the undersigned.

Respectfully,

ECS-TEXAS, LLP

Brent Crawford, E.I.T Michael Sorgenfrei, P.E. Staff Geotechnical Engineer Geotechnical Department Manager

Electronic seal approved by Michael Sorgenfrei, P.E. on July 27, 2015

Distribution: e-mail/Addressee

GEOTECHNICAL REPORT

PROJECT:

Proposed Keesee Multifamily Development 10413 Interstate Highway 35 South

Austin, Texas

CLIENT:

Ardent Residential, L.P. 5453 Burnet Road, Suite 203

Austin, Texas 78756

ECS PROJECT NUMBER: 17-4312

DATE: July 27, 2015

TABLE OF CONTENTS

Section Page

PROJECT OVERVIEW .............................................................................................................. 1 Authorization ........................................................................................................................... 1 Site and Project Information .................................................................................................... 1 Summary of Exploration .......................................................................................................... 1

EXPLORATION PROCEDURES ............................................................................................... 2 Field Exploration ..................................................................................................................... 2 Laboratory Testing .................................................................................................................. 3

EXPLORATION RESULTS ........................................................................................................ 4 Local Geology ......................................................................................................................... 4 Summary of Subsurface Conditions ........................................................................................ 4 Groundwater Observations ..................................................................................................... 5

GEOTECHNICAL ANALYSIS .................................................................................................... 6 Potential Vertical Rise ............................................................................................................. 6 Slab-on-Grade Foundations .................................................................................................... 7 Retaining Walls ....................................................................................................................... 8 Pavement Design .................................................................................................................. 10 Earthwork .............................................................................................................................. 14 Drainage ............................................................................................................................... 15

CONSTRUCTION CONSIDERATIONS.................................................................................... 16 Earthwork .............................................................................................................................. 16 Shallow Foundations ............................................................................................................. 16 Utility Trench Construction .................................................................................................... 16 Sidewalks and Flatwork ......................................................................................................... 17

FIELD OBSERVATIONS & TESTING ...................................................................................... 18 Earthwork and Pavement ...................................................................................................... 18 Slab-on-Grade Foundations .................................................................................................. 18

EXCAVATIONS ....................................................................................................................... 19

LIMITATIONS .......................................................................................................................... 20 Figures Appendix

Figure 1: Site Location Plan Test Boring Logs

Figure 2: Regional Geology Map Reference Notes for Boring Logs

Figure 3: Boring Location Diagram USCS Information

Lab Testing Summaries

Proposed Keesee Multifamily ECS Project 17-4312

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PROJECT OVERVIEW

Authorization

ECS-Texas, LLP (ECS) conducted this subsurface exploration and geotechnical engineering evaluation in accordance with ECS Proposal No. 17-4390 and No. 17-4496 dated February 18, 2015 and June 9, 2015 respectively. This study was authorized on February 18, 2015 and on June 10, 2015 by Mr. Art Carpenter of Ardent Residential, via signature of the referenced proposals.

Site and Project Information

The approximate 7.38-acre site is located at 10413 Interstate Highway 35 South, on the east side of IH-35, north of the Onion Creek Subdivision and south of the Onion Creek Apartments. The site is vacant, has a relatively gentle slope from northeast to southwest, and contains moderate density trees. A Site Location Plan is enclosed in the Appendix for reference. The project will include the construction of a new 4-story multifamily building and surrounding surface parking. A wood-framed building founded at grade and utilizing a slab-on-grade foundation is anticipated, with grade beam line loads of about 4 kips per linear foot. Existing elevations within the building footprint very from about El. 631 feet to El. 635 feet, with finished floor elevation understood to be at 638 feet.

Summary of Exploration

The purpose of this exploration was to explore the subsurface conditions at the site and to develop geotechnical engineering recommendations for the project. We accomplished the purpose by:

1. Placing boring locations on the site. 2. Notifying utility locators prior to field exploration. 3. Drilling 10 test borings total to explore subsurface conditions. 4. Performing laboratory testing on selected representative soil samples to classify and to

evaluate pertinent physical and engineering properties. 5. Analyzing the field and laboratory data and performing engineering analyses. 6. Preparing this geotechnical engineering report.


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EXPLORATION PROCEDURES

Field Exploration

Four (4) test borings were initially drilled at the site to depths of 25 feet each below the existing ground surface. Following these borings, six (6) more borings were drilled at the site to depths of 15 feet each below the existing ground surface. The locations of the borings were marked in the field by a representative of ECS and are illustrated on Figure 3 – Boring Location Diagram. The borings were located by overlaying the site plan on Google Earth imagery and obtaining boring coordinates. The borings were then located in the field using handheld GPS equipment. The boring locations should be considered approximate.

Drilling was performed using a truck-mounted drill rig and continuous flight auger drilling methods. Boreholes were backfilled with available auger cuttings or sealed at the surface by collapsing the upper part of the borehole. Some settlement of backfill may occur with time and holes may remain open due to insufficient auger cuttings.

Shelby Tube Sampling

Soil samples were obtained using a Shelby Tube sampler in general accordance with ASTM D 1587. In this sampling procedure, a thin walled, seamless steel tube with a sharp cutting edge is pushed hydraulically into the soil and a relatively undisturbed soil sample is obtained. Samples were removed from samplers in the field, visually classified, and appropriately sealed in sample containers to preserve their in-situ moisture contents.

Where possible, small scale penetration tests were performed on samples of cohesive soil with the use of a calibrated hand “pocket” penetrometer. In this test, the unconfined compressive strength of a soil sample is estimated to a maximum of 4.5 tons per square foot (tsf) by measuring the resistance of the soil sample to the penetration of a small diameter, calibrated, spring-loaded cylinder.

Penetration Tests and Sampling

Standard Penetration Tests (SPTs) were performed to obtain representative samples and penetration resistance measurements in general accordance with ASTM D 1586. Soil samples were obtained at various intervals with the 1.625-inch inside diameter, 2-inch outside diameter, Split Spoon sampler. The Split Spoon sampler was first seated 6 inches to penetrate any loose cuttings, and then was driven an additional 12 inches with blows of a 140-pound hammer falling 30 inches. The number of hammer blows required to drive the sampler each 6-inch increment was recorded. The penetration resistance “N-value” is defined as the number of hammer blows required to drive the sampler the final 12 inches and is indicated on the test boring logs. In very dense materials such as weathered rock material, the SPT test is usually stopped after 50 blows from the hammer and the measurement is recorded as 50 blows per distance penetrated (i.e. 50 over 3 inches).

Rock Coring

Rock coring with the aid of an air compressor was performed using an Nx core barrel with an inside diameter of 2.125 inches. The rock core was measured to determine the Recovery Ratio (REC) and the Rock Quality Designation (RQD) index values. The REC value is equal to the


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total length of core recovered divided by the total length of core advance. The RQD value is defined as the percentage of core advance that is recovered in segments that are 4 inches or longer and is a qualitative index of the quality or physical integrity of the rock. Rock coring was performed in general accordance with ASTM D 2113. Rock core samples were placed in cardboard core boxes for transport to our laboratory.

Laboratory Testing

Samples were transported to the ECS laboratory where they were examined and visually classified by an ECS geotechnical engineer using the Unified Soil Classification System (USCS) in general accordance with ASTM D 2488. To aid in classification of the soils and determination of their selected engineering characteristics, a testing program was conducted on selected samples in general accordance with the following standards:

Laboratory Test Test Standard

Sieve Analysis ASTM D 422

Moisture Content ASTM D 2216

Atterberg Limits ASTM D 4318

Results of the laboratory tests are included in the Appendix on the respective boring logs and are presented on the Laboratory Test Summary tables. Laboratory test results were used to classify the soils encountered as outlined by USCS in general accordance with ASTM D 2487. The USCS group symbols for each soil type are indicated in parentheses with the soil descriptions on the test boring logs. A brief explanation of the USCS is included in the Appendix.

All samples were returned to our laboratory in Austin, Texas. Samples not tested in the laboratory will be stored for a period of 60 days subsequent to submittal of this report and will be discarded after this period, unless we receive alternate instructions regarding their disposition.


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EXPLORATION RESULTS

Local Geology

Based on a review of the Geologic Map of the Austin Area1, the site is mapped as being underlain by tributary terrace deposits (Qtt) of Quaternary geologic age. The Austin Formation (Kau) of Cretaceous geologic age is mapped to the north, east and west of the terrace deposits.

Tributary terrace deposits are alluvial deposits and represent soils that have been transported for some distance by water or stream processes. These deposits generally consist of a mix of soil types and each grouping or classification is a reflection of the stream energy during deposition. They range in type from low energy, fine-grained floodplain deposits, to high energy, coarse-grained channel deposits. The alluvium in this area is known to contain clayey soils with high plasticity index. Alluvial deposits tend to vary more substantially over shorter distances as opposed to other deposit types as a result of their depositional environment.

The Austin Chalk Formation in this area generally consists of limestone, chalk and marl. The materials generally vary from off-white to light brownish gray in color. Weathering of the upper portion of the strata often results in a clay chalk mix. The thickness of the Austin Chalk is reported as 300-400 feet thick.

Summary of Subsurface Conditions

The strata descriptions provided herein are of a generalized nature to highlight the major soil/rock stratification features and soil/rock characteristics. The test boring logs provided in the Appendix should be reviewed for specific information at each location. The stratification of the soil and rock represents our interpretation of the subsurface conditions at the test boring locations based on observations by an ECS geotechnical engineer of the test boring samples. Variations from the conditions shown on the test boring logs could occur in areas in between and away from the test borings. The stratification lines shown on the test boring logs represent approximate boundaries between soil and rock types and condition, and the transitions may be gradual rather than distinct.

Information from the test borings seen in Figures 3 and 4 indicate that the soil/rock stratigraphy may generally consist of 3 distinguishable strata within the exploration depth of 25 feet. A detailed description of each stratum is included in the table on the following page.

1 Geologic Map of the Austin Area, Texas, Bureau of Economic Geology, University of Texas at Austin,

Reprinted 1992.


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Stratum Range of

Depth (ft.)

Stratum Description and Classification

WC range

PI range

PP range

N range

WC avg.

PI avg.

PP avg.

N avg.

I 0 – (2-6) Fat Clay with Sand (CH); dark

brown to brown; stiff to very stiff

3-37 26-55 1.5-4.5

--

24 46 3.2 --

II (2-6) – (13½-20½)

Sandy Lean Clay (CL) to Clayey Sand (SC); light brown;

generally stiff to very stiff and medium dense

6-20 9-39 0.5-4.5

12-91/11”

13 15 2.9 41/10”

III (13½-

20½) – 25

Limestone, Chalk and Marl; off-white to light gray or light brown;

generally very hard

-- -- -- 50/1”-50/2”

-- -- -- 50/2”

Notes: Depth- Soil Stratum depth from existing ground surface at the time of our geotechnical exploration WC- Water Content, %

PI- Plasticity Index PP- Pocket Penetrometer value, tons per square foot, up to 4.5 tsf N- Standard Penetration Test (SPT) value, field blows per foot

Groundwater Observations

The borings were advanced using relatively dry drilling techniques to their full depths, enabling the potential detection of the presence of groundwater during drilling operations. Groundwater was encountered only in boring P-3 at a depth of 22.5 feet beneath existing grade. Upon completion of drilling operations, the boreholes were backfilled with soil cuttings generated during our drilling operations.

It should be noted that water levels in open boreholes may require several hours to several days to stabilize depending on the permeability of the soils and that groundwater levels at the site may be subject to seasonal conditions, recent rainfall, drought or temperature effects. Clays and massive bedrock are generally not conducive to the presence of groundwater; however, gravels, sands and silts, and open fractures and solution features; where present, can store and transmit “perched” groundwater flow or seepage. Therefore, groundwater conditions should be evaluated just prior to and during construction.


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GEOTECHNICAL ANALYSIS

The following recommendations have been developed on the basis of the previously described project characteristics and subsurface conditions. If there are any changes to the project characteristics or if different subsurface conditions are encountered during construction, ECS should be consulted to determine if any changes to the recommendations presented in this report are required.

In general, the proposed development at the site is considered geotechnically feasible provided the recommendations of this report are implemented in the design and construction of the project. The predominant geotechnical and geological issues that need to be addressed at this site are the highly expansive soil conditions. The field and laboratory data acquired during this study indicate that the upper clay soils (within the upper approximate 15 feet) are volumetrically unstable. These soils generally have a very high potential to experience volumetric changes with fluctuations in moisture content. A further discussion of the soil expansion potential is provided in the Potential Vertical Rise (PVR) section below.

The proposed building at the site can be supported by a monolithic beam and slab-on-grade foundation system. Specific design recommendations for foundations and other geotechnical related aspects of the project are discussed in the following subsections.

Potential Vertical Rise

Structural damage and/or cosmetic/operational distress can be caused by volume changes in clay soils. The expansive soils found at this site are capable of swelling and shrinking in volume dependent on potentially changing soil water conditions during or after construction. Clays can shrink when they lose water and swell (grow in volume) when they gain water. The potential of expansive clays to shrink and swell is related to; amongst other things, the Plasticity Index (PI). Clays with a higher PI generally have a greater potential for soil volume changes due to moisture content variations.

Several methods exist to evaluate swell potential of expansive clay soils. We have estimated potential heave for this site utilizing the TxDOT method (Tex 124-E). The Tex 124-E method provides an estimate of potential vertical rise (PVR) using the liquid limits, plasticity indices, and existing water contents for soils. The PVR is estimated in the seasonally active zone, which can be up to about 15 feet in the site vicinity.

Estimated PVR values are based upon assumed typical changes in soil moisture content from a dry (existing) to wet condition; however, soil movements in the field depend on the actual changes in moisture content. Thus, actual soil movements could be less than that calculated if little soil moisture variations occur, or the actual movement could exceed the estimated values if actual soil moisture content changes exceed the PVR methods assumed dry and wet limits. This condition is often the result of excessive droughts, flooding, “perched” groundwater infiltration, poor surface-drainage, excessive irrigation adjacent to building foundations, and/or leaking irrigation lines or plumbing.

We estimate the existing PVR in the proposed building pad area to range from about 2 to 2½ inches. Recommendations are provided herein to reduce the PVR to about 1 inch by undercutting the existing ground as required based on the proposed finished floor elevation, and


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then filling to the proposed pad grade with at least 4 feet of properly compacted select fill. All fill placed in the building pad area should consist of properly compacted select fill materials.

In this general area, most structural and geotechnical engineers consider a PVR of 1 inch to be within acceptable tolerances for properly designed beam and slab-on-grade foundations. However, this movement does not take into consideration the movement criteria required or perceived by the facility owner or occupants. These “operational” performance criteria may be, and often are, more restrictive than the structural criteria or tolerances.

Grade supported foundation or floor slab movements that approach 1 inch may cause doors to stick, cracks in sheetrock or brittle floor covering, cracks in exterior finishes and other forms of cosmetic distress. Measures can and should be taken during the design and construction of the facility to help limit the extent and severity of these types of distress. However, these magnitudes of movement typically do not cause “structural distress.”

Slab-on-Grade Foundations

As previously discussed, a monolithic beam and slab-on-grade foundation system can be utilized to support the planned structure. The rigidity of a beam and slab foundation system can reduce the effects of differential soil movement due to compression of soils due to structural loads or shrink-swell due to expansive soils. This type of slab can be designed with conventionally reinforced perimeter and interior stiffening grade beams, and/or with post-tensioning adequate to provide sufficient rigidity to the slab element. The grade beam width and depth will be determined by the project Structural Engineer. Grade beams may be thickened and widened at column or load bearing wall locations to support concentrated load areas, if necessary. All grade beams and floor slabs should be adequately reinforced with steel to reduce cracking and support bending moments caused by loading and minor movements of foundation soils.

The design values below are based on the subsurface conditions encountered during this exploration and the recommendations for building pad grading provided herein. If the building location or finished floor elevation changes, we should be contacted to review; and if necessary, provide alternate design parameters based on the changed conditions. These parameters are provided to assist the Structural Engineer in design of a foundation that is stiffened using grade beams (ribs), post tensioning, or a combination thereof.


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Post-Tensioned Slab Parameters PTI 3

rd Edition with 2008 Supplements

Design Parameter Design Values

Allowable Bearing Capacity 2,500 PSF

em Edge 4.2 Feet

em Center 8.3 Feet

ym Edge 1.4 Inches

ym Center 1.0 Inches

BRAB/WRI Slab Parameters

Design Parameter Design Values

Allowable Bearing Capacity 2,500 PSF

Effective PI 30

Climatic Rating 18

Unconfined Compressive Strength (TSF) 1.5

Soil-Climate Support Index (1-C) 0.17

The allowable bearing capacities listed above can be increased by one-third (⅓) when including transient wind or seismic loading. To utilize the parameters listed above, the subgrade should be prepared in accordance with the “Earthwork” sections of this report including the placement of at least 4 feet of properly compacted select fill.

Slab-on-grade foundations at this site should be expected to undergo some vertical movements. These movements can potentially cause cosmetic distress and must be accounted for in the design process. Contraction, control, or expansion joints should be designed and placed in various portions of the structures. Properly planned placement of these joints will assist in controlling the degree and location of material cracking which normally occurs due to material shrinkage, thermal effects, soil movements, and other related structural conditions.

Where moisture sensitive floor coverings or equipment will be installed, we recommend that at least a 10 mil vapor retarder be used beneath the slab. The vapor retarder should conform to ASTM E1745, Class C or better and shall have a maximum water vapor permeance of 0.044 when tested in accordance with ASTM E96. Consideration to specifying a thicker, more durable vapor retarder should also be made where anticipated construction traffic dictates. If a vapor retarder is considered to provide moisture protection, special attention should be given to the surface curing of the slabs to minimize uneven drying of the slabs and associated cracking and/or slab curling. Please refer to the latest edition of ACI 302.2R-06 Guide for Concrete for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials and ASTM E 1643 Standard Practice for Installation of Water Vapor Retarders Used in Contact with Earth or Granular Fill Under Concrete Slabs for additional guidance on this issue.

Retaining Walls

The magnitude of the lateral earth pressures on retaining walls is dependent upon the in-situ material behind the wall; and if displaced, the type of material used to backfill the “active zone” behind the wall. The magnitude of the earth pressure is also dependent upon whether the active zone is allowed to drain water freely. The active zone can be considered as the area behind the


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structure within a boundary created by a 45 degree angle extending from the outside edge of the foundation heel upward to the ground surface. The lateral earth pressures for drained, level soil backfill are expressed in terms of pounds per cubic foot (psf/ft.) “equivalent fluid” weight applied in a triangular distribution pattern as listed below. If the walls are free to deflect or rotate slightly at the top they may be designed using “active” lateral earth pressures. If the walls are laterally restrained at the top, “at-rest” lateral earth pressures should be used for the retaining wall design. Where multiple material types are used within the active zone, the higher values below should be used. The equivalent fluid weights shown in the table do not include any safety factors and do not account for any surcharges. Lateral loads from uniform surcharges on the wall backfill can be multiplied by the below earth pressure coefficients and should be considered as rectangular loads acting on the full wall height. An increase of 1 pcf and 1.5 pcf should be added to the active and at-rest earth pressures; respectively, for each degree of inclination of backfill.

Soil Description Total Unit

Weight (pcf)

Active Earth Pressure

Coefficient

At-Rest Earth Pressure

Coefficient

Drained Active Earth

Pressure (psf/ft)

Drained At-Rest Earth Pressure

(psf/ft)

Undisturbed or Compacted Native

Soil 120 0.42 0.59 51 71

Imported Select Fill

120 0.36 0.53 43 64

ASTM C33 Size #56, #57 or #467

Stone 110 0.33 0.50 37 55

Compacted Manufactured

Sand (< 8% Fines) 120 0.33 0.50 40 60

Compacted TxDOT Item 247,

Type A or C, Grade 1 or 2 Base

135 0.26 0.41 35 56

For sliding resistance, a coefficient of friction of 0.32 between the base of the foundation elements and underlying soils is recommended. In addition, for footings cast directly against undisturbed native soils, a passive resistance equal to an equivalent fluid applying 250 psf/ft pressure may be used to resist lateral forces. The passive resistance should be neglected in the upper 18 inches unless the ground immediately in front of the footing is covered with concrete or other impervious pavement. The above values are ultimate values, and an appropriate safety factor should be used in design. The subject retaining walls can be supported by shallow foundations bearing on undisturbed soils or compacted fill using an allowable bearing capacity (gross) of 2,500 psf at the bearing surface. Footing excavations should have firm bottoms and be free from excessive slough prior to concrete or reinforcing steel placement. The geotechnical engineer should be allowed to observe foundation excavations prior to reinforcing steel or concrete placement to confirm anticipated ground conditions.


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Retaining walls should be waterproofed as required by the project architect. Subdrain systems and/or drainboard composites are recommended to reduce hydrostatic pressures on retaining walls. A subdrain system can consist of 4 inch perforated pipe placed at the base of the retaining wall and surrounded by ASTM C33 Size #57 stone completely wrapped in Mirafi 140N or 160N filter fabric, or equivalent approved by the geotechnical engineer. The drainrock wrapped in fabric should be at least 12 inches wide and extend from the base of the wall to within two feet of the ground surface. The upper two feet of backfill should consist of compacted native soil or other impervious pavement. The retaining wall drainage system should be sloped to outlet pipes draining away from the foundations and pumped to the surface as grades require. Care should be exercised not to outlet subdrains to areas subject to inundation. The subdrain system should be inspected periodically to ensure functionality; failure of the subdrain system will affect the design lateral earth pressures and the retaining wall stability. If subdrain systems are determined to not be practical, hydrostatic pressures should be incorporated into the wall design. As an alternative to the drainrock and fabric, a prefabricated drainage composite (drainboard) such as MiraDRAIN 2000, or approved equivalent, may be used behind the retaining wall. The drainboard should extend from the base of the wall to within two feet of the ground surface. The drainboard should be installed in accordance with manufacturer specifications.

Where free-draining, clean granular materials will be used to backfill the walls, and where structures, pavements or other improvements will be located closely behind the retaining walls, it is recommended that all clean granular materials be separated from the soils and fills with the use of the above stated filter fabrics. The use of the filter fabric can greatly reduce the intrusion of the soils into the void spaces of the clean granular materials. Intrusion of the soils into the void spaces causes a net ground loss, and can cause settlement of the ground surface and overriding improvements.

The retaining wall backfill should be compacted and tested in maximum 8 inch lifts to be at least 95 percent of the standard Proctor maximum dry density (ASTM D698) at moisture contents between minus one (-1) and plus three (+3) percentage points of optimum.

Pavement Design

ECS has prepared the following recommendations for the design and construction of both flexible and rigid pavement systems for use on the subject project. The “AASHTO Guide for Design of Pavement Structures” published by the American Association of State Highway and Transportation Officials was used to develop the pavement thickness recommendations in this report. This method of design considers pavement performance, traffic, roadbed soil, pavement materials, environment, drainage and reliability. Each of these items is incorporated into the design methodology.

We have based our analysis on the following ESAL information and pavement-related subgrade design parameters, which are considered to be typical for the area. A CBR (California Bearing Ratio) value of 2.5 percent was selected for design purposes. The CBR value was estimated based on ECS’s knowledge and experience with similar soils and projects in this area.


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Reliability 70

Initial Serviceability Index, Flexible Pavements

4.2

Initial Serviceability Index, Rigid Pavements

4.5

Terminal Serviceability Index, All Pavements

2.0

Standard Deviation, Flexible Pavements

0.45

Standard Deviation, Rigid Pavements

0.35

Based on the design parameters listed above, we developed recommendations for “light duty,” “moderate duty” and “heavy duty” pavement sections. “Light duty” pavements are intended for general parking areas with passenger vehicles only and have an approximate capacity of at least 20,000 ESAL. “Moderate duty” pavements are intended for areas subject to channelized traffic and delivery areas and have an approximate ESAL capacity of at least 80,000. “Heavy duty” pavements are intended for areas subject to heavier vehicles with extensive turning, starting and stopping, such as the pavement aprons associated with trash enclosures, and have an approximate ESAL capacity of at least 250,000. If the owner or other members of the design team feel that the ESAL values used for design are not appropriate, ECS should be notified in writing, so any new information can be reviewed, and if necessary, the pavement recommendations revised accordingly.

The minimum recommended thickness for both hot mixed asphalt concrete (HMAC) and reinforced Portland cement concrete (PCC) pavement sections are presented in the following table for the described “light”, “moderate” and “heavy” traffic conditions.

RECOMMENDED PAVEMENT SECTION OPTIONS

Component

Light-Duty 20,000 ESALs

Moderate-Duty 80,000 ESALs

Heavy-Duty 250,000 ESALs

Rigid Asphalt Rigid Asphalt Rigid Asphalt

Portland Cement Reinforced Concrete 5 in. -- 5.5 in. -- 7 in. --

Hot Mixed Asphalt Concrete (HMAC) -- 2.0 in. -- 2.5 in. -- --

Crushed Limestone Base (CLB) -- 9 in. -- 11 in. -- --

The pavement sections described above are considered suitable for general-purpose usage for the anticipated subgrade conditions and were designed using the AASHTO Pavement and Analysis System. An aggressive maintenance program to keep joints and cracks sealed to prevent moisture infiltration will help extend the pavement life.

We recommend that rigid pavement sections be used in all heavy truck traffic areas. The concrete pavement should extend throughout the areas that require extensive turning and maneuvering of the delivery vehicles, etc. Waste dumpster pads, loading areas and other heavily loaded pavement areas that are not designed to accommodate these conditions often experience localized pavement failures, particularly if flexible pavement sections are used.


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Pavement Materials

Recommendations regarding material requirements for the various pavement sections are summarized below:

Portland Cement Concrete - Concrete used for paving should have a minimum compressive strength of 3,000 psi at 28-days. The air content at the point of placement should range from 2 to 4 percent. The concrete pavements should be reinforced and jointed per current ACI recommendations.

Hot Mix Asphalt Concrete (HMAC) Surface Course - The asphalt concrete surface course should be plant mixed, hot laid Type D (Fine Graded Surface) or Type C (Coarse Graded Surface Course) meeting the specifications requirements of TxDOT Item 340 and specific criteria for the job mix formula. The mix should be compacted to between 92 and 97 percent of the maximum theoretical density as determined by TEX-227-F.

Crushed Limestone Base Course - Crushed limestone base should be placed in maximum six (6) inch compacted lifts. The base materials should be compacted to at least 95 percent of the maximum dry density as determined by ASTM D 1557. Flexible base materials should be moisture conditioned to between optimum and plus three (+3) percentage points of the optimum moisture content during compaction. Flexible base materials should meet all requirements specified in 2004 TxDOT Standard Specification Item 247, Type A, Grade 1 or 2.

Rigid Pavement

Joints are typically placed in rigid pavements to control cracking, to facilitate construction, and to isolate a section of pavement from a structure or an adjacent pavement section. Joints used to control cracking are typically known as contraction or control joints as they are intended to control cracking that arises out of the shrinkage of concrete as it cures. Construction joints are used to provide clean breaks between pavement sections that result from the construction process. Isolation joints (or expansion joints) are used to separate the pavement from other structures or pavements and typically include the use of compressible materials in the joint as opposed to contraction or construction joints. Contraction joints should be spaced no greater than 15 feet between the nearest parallel joints with joint depths of at least one-quarter (¼) of the slab thickness. Contraction and construction joints should be no wider than one-eighth (⅛) of an inch whereas isolation joints may be up to one (1) inch wide.

Steel reinforcement is commonly used where subgrade conditions are not likely to provide uniform support to the concrete pavement. Generally, sites with expansive soils present are often unable to provide such support to rigid pavement sections. Therefore, reinforcing steel should be used to span between construction and isolation (expansion) joints and should consist of at-minimum No. 3 bars spaced 18 inches on-centers each way. The rebar should be Grade 60 steel.

As with steel reinforcement, in situations where the subgrade may not provide uniform support to the pavement, dowels are commonly used to transfer loads across joints. Smooth dowels can be used for this purpose and should be utilized as recommended in the following table.


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Dowel Design Information

Slab Thickness, in.

Dowel Diameter, in.

Min. Dowel Embedment

Each side, in.

Min. Dowel Length, in.

Dowel Spacing On-Centers, in

5.0 ⅝ 5 12 12

5.5 ¾ 6 14 12

7.0 ⅞ 7 16 12

The joint and reinforcing design of a rigid pavement system is largely a function of geometry for the pavement area. The proper length of concrete panels (defined as the distance between discontinuous pavement sections; e.g. between construction or isolation joints, or a combination of the two) and the location of contraction, construction, and isolation (expansion) joints are not included as a function of the above concrete pavement guidelines. Rather, these features should be determined based on the geometry and construction sequencing of the pavement. Actual joint spacing should be based on actual pavement areas and final panel lengths so that joints are evenly spaced. Joints should be designed to form approximately square panels where geometrically feasible. The values provided herein are guidelines and the recommendations selected by the project civil engineer and any guidelines not provided or mentioned herein should not exceed the American Concrete Institute (ACI) 330R recommendations.

General Pavement Design Comments

Longitudinal cracks and apparent distress due to expansive soils may appear in the pavement after construction and the introduction of landscape irrigation. These cracks and distress are not pavement failures with respect to traffic support, although they may be aesthetically undesirable. In addition, without regular maintenance, the cracks can allow additional moisture intrusion and rapid degradation of the pavement section. The pavement sections are primarily designed to support the traffic and will not resist the forces generated by swelling soils.

Positive drainage should be provided on and around pavement areas to prevent ponding of water. Irrigation of lawn and landscaped areas adjacent to the pavements should be moderate, with no excessive wetting or drying of soils adjacent to the pavements. If landscaped islands are provided, they should be designed to restrict excess water from migrating to the pavement subgrade by using self-contained beds, raised planter boxes, vertical moisture barriers, and/or edge drains. Curbs should extend through the base course and at least 4 inches into the underlying subgrade. Good perimeter surface drainage guiding surface water away from the pavement area is also recommended.

Utility trench backfill can act materially different than adjacent natural soils, even if properly placed and compacted. Differential movements may occur which can lead to crack development near the edges of utility trenches, riser structures, manholes, etc., with the more noticeable cracks appearing in deeper fill zones. This type of cracking is considered typical for this type of construction if special care is not taken to prevent it.

As an option to help mitigate the effects of differential soil movements, we recommend that fill placed at depths greater than 5 feet be compacted to no less than 98% of the maximum dry density between minus one (-1) and plus three (+3) percentage points of the optimum moisture content (ASTM D 698).


14

Earthwork

Preparation of the subgrade soils for areas to receive structures, fills or pavements should be conducted in accordance with the recommendations presented in the following sections.

General Site Preparation

Areas that will support structures, fills or pavements must be properly prepared. Existing vegetation, organic laden soil, loose or soft soils, abandoned underground utilities and any other deleterious materials must be removed from the proposed construction areas and properly disposed. Excavations resulting from the removals should be cleaned down to firm soils and backfilled with engineered fill in accordance with this report. To mitigate soil expansion potential in the building pad area, it is recommended that existing soils in the building pad area be removed as required to allow for at least a 4 foot thick compacted select fill course beneath the building pad. All fill placed in the building pad area is recommended to consist of select fill materials. The stripping and removal operations and select fill placement to finished pad grade should extend to at least 3 feet beyond the building perimeter and beneath adjacent movement sensitive concrete flatwork.

After stripping and cuts have been completed, the subgrade soils should be scarified, moisture conditioned and compacted to at least 95 percent of the maximum dry density as determined by ASTM D 698 to a depth of at least 8 inches. The soils should be moisture conditioned to between optimum and plus four (+4) percentage points of the optimum moisture content just prior to compaction. Proof-rolling should be performed where possible with a heavy (minimum 20 ton) rubber-tired vehicle such as a loaded dump truck. Soils that are observed to rut or deflect excessively under the moving load should be under-cut and replaced with compacted structural fill that meets the requirements of the section titled Engineered Fill. All proof-rolling and under-cutting activities should be observed by ECS and should be performed during periods of dry weather.

After removals, subgrade preparation, proof-rolling and evaluation has been completed, fill placement may begin where required. Excavated soil that meets the material requirements in the following section may be used as compacted fill. If suitable fill soils have to be imported to the site they must meet the material and compaction requirements of the following section.

Engineered Fill

Fills in proposed pavement areas and landscaped areas can consist of on-site or imported soils, provided they meet the requirements described below. To mitigate soil expansion potential, at least 4 feet of compacted select fill should be placed in the building pad area and should consist of imported soils meeting the select fill requirements below. Proposed engineered and select fill should be evaluated and tested by ECS prior to placement in the field.

All fill materials should be clean of organics, construction debris, deleterious materials, and should be free of rocks larger than 4 inches in greatest dimension. Imported engineered fill should have a PI of less than 35. Select fill should have a PI of less than 20. Proposed engineered and select fill should be evaluated and tested by ECS prior to placement in the field.

Consideration should be given to creating an “all weather” working surface with the upper six (6) inches of the building pad. Such a working surface should consist of compacted TxDOT Item 247


15

Type A, Grade 1 or 2 Base materials. The use of an “all weather” working surface can significantly improve the accessibility of the site to construction traffic during periods of wet weather.

ECS recommends that engineered fill and select fill be placed in horizontal loose lifts of not more than 8 inches in thickness. Lift thickness should be decreased when using light compaction equipment. Engineered fill should be compacted to at least 95% of the standard Proctor maximum dry density at moisture contents within the range of optimum to plus four (+4) percentage points of the optimum moisture content (ASTM D 698). Select fill should be compacted to at least 95% of the standard Proctor maximum dry density at moisture contents within the range of minus one (-1) to plus three (+3) percentage points of the optimum moisture content (ASTM D 698).

The upper 18 inches of fill outside of the structure and adjoining concrete flatwork should consist of a properly compacted low permeability clay (CL) soil to reduce infiltration of moisture into the fill materials comprising the building pad. This clay layer may be replaced with asphalt or concrete pavement that extends to the edge of the structure foundation.

Drainage

Water should not be allowed to collect in the foundation excavations, on foundation surfaces, or on prepared subgrades within the construction area either during or after construction. Undercut or excavated areas should be sloped toward one corner to facilitate removal of any collected rainwater, groundwater, or surface runoff. Final grading should be designed to promote positive drainage away from the structures and pavements. Soil areas within 10 feet of the building should slope at a minimum of 5 percent away from the structure. Adjacent pavements and concrete hardscape should slope at 1½ to 2 percent away from the structure. Roof leaders and downspouts should discharge onto paved surfaces sloping away from the structures or into a closed pipe system which outfalls to the street gutter pan or directly to the storm drain system.


16

CONSTRUCTION CONSIDERATIONS

Earthwork

Clayey soil is very sensitive to changes in moisture content. Subgrade support capacity will deteriorate when the moisture content increases. Effort should be made to keep fill, slab, pavement, and foundation subgrade areas properly drained and free of ponding water. Vehicle traffic on top of the subgrade should be prevented when the subgrade is visibly wet, and should be kept to a minimum at other times. Site grading and fill placement should preferably be performed during drier seasons of the year.

Fill materials should not be placed on soils that have been recently subjected to precipitation or saturation. All wet soils should be removed or allowed to dry prior to continuation of fill placement operations. Borrow fill materials, if required, should not contain wet materials at the time of placement.

If any problems are encountered during the earthwork operations, or if site conditions deviate from those encountered during our subsurface exploration, the Geotechnical Engineer should be notified immediately to determine the effect on recommendations expressed in this report.

Certain construction practices can reduce the magnitude of problems associated with moisture content increases of subgrade soil for slabs and areas to receive compacted fill. The contractor should seal exposed subgrade areas at the end of the work day with a smooth drum roller to reduce the potential for infiltration of water into the subgrade. Site grading should be continuously evaluated to assure that surface runoff will drain away from slab and fill areas.

Shallow Foundations

Exposure to the environment may weaken the soils at the foundation bearing level if the foundation excavations remain exposed during periods of inclement weather. Therefore, foundation concrete should be placed as soon as possible after final excavation is achieved and after the subgrade has been evaluated by a representative of the geotechnical engineer. If the bearing soils are softened by surface water absorption or exposure to the environment, the softened soils must be removed from the foundation excavation bottom prior to placement of concrete. If the foundation excavation must remain open overnight, or if rainfall is apparent while the bearing soils are exposed, we recommend that a 1 to 3-inch thick "mud mat" of "lean" concrete be placed over the exposed bearing soils before the placement of reinforcing steel.

Utility Trench Construction

Utility trenches in the building pads should be backfilled above the utility bedding and shading materials with select fill, and general fill material outside the building pad area. The backfill materials should be placed in lifts not to exceed 8 inches loose measure, or 6 inches compacted measure. Thinner lifts may be required when using hand held compaction equipment. Backfill materials should be moisture conditioned to between optimum and plus three (+3) percentage points of the optimum moisture content and compacted to at least 95 percent of the maximum dry density as determined by ASTM D 698.


17

Utility trenches should be sealed with lean concrete, lean clayey soil, controlled low-strength material or flowable fill where the utility approaches and enters the building pad select fill overbuild. This would reduce the potential for migration of water beneath the building through the bedding and shading materials in the utility trench.

Flexible connections should be considered where utilities connect to buildings or pass through building foundations/slabs to allow for the anticipated Potential Vertical Rise differential. This could be provided by special flexible connections, pipe sleeving with appropriate waterproofing, or other methods.

Sidewalks and Flatwork

Where movement sensitive flatwork will be constructed adjacent to the buildings, consideration should be given to reducing the PVR value in the flatwork areas to reduce differential movements and associated door jamming, tripping hazards, etc. Doweling the flatwork to the building foundation at common openings will further help to reduce the potential for differential movements and trip hazards. Proper drainage around grade supported sidewalks and flatwork is also very important to reduce potential movements. Elevating the sidewalks where possible and providing rapid, positive drainage away from them will reduce moisture variations within the underlying soils, and will therefore provide valuable benefit in reducing the full magnitude of potential movements from being realized.


18

FIELD OBSERVATIONS & TESTING

Personnel from ECS should perform the field observations and testing recommended in this report because of our familiarity with the project and site conditions. The performance of foundations and pavements is primarily controlled by the quality of the construction. To prevent misinterpretation of our recommendations, ECS should be retained to perform full time quality control testing, inspection, and documentation during construction of the foundations and pavements.

The performance of slabs and pavements placed on new fill material is controlled by the quality of the compaction and the materials selection for the fill material. ECS should be retained to perform quality control testing and inspection during selection, placement, and compaction of the fill material.

Earthwork and Pavement

Field observations and testing should be performed during the earthwork operations to document proper construction. Stripping should be observed by the Geotechnical Engineer to help locate unsuitable materials that should be removed prior to placement of fill, slab, or pavement materials. Field observation and inspection should include final approval of subgrades prior to placement of compacted fill, slabs, or pavement. Proof-rolling should be performed by a heavy rubber-tired vehicle such as a loaded dump truck on slab and pavement subgrades. Appropriate laboratory tests such as Proctor moisture-density tests and Atterberg Limits should be performed on samples of fill material and pavement base course material. Field moisture-density tests and visual observation of lift thickness and material types should be performed during compaction operations to document that the construction satisfies material and compaction requirements. The frequency of field density tests should be in accordance with local or state municipal agency guidelines.

Slab-on-Grade Foundations

Prior to concrete placement, the Geotechnical Engineer should observe the foundation excavations to determine if the foundations are being placed on suitable materials and to determine if all loose materials have been removed. Dynamic Cone Penetrometer (DCP) tests can be performed to help evaluate the foundation bearing surfaces. In areas where the subgrade is soft or loose, the soil should be removed and foundations lowered to bear on firm compacted soils, or foundation subgrade elevations can be restored using properly compacted select fill or lean concrete (e.g. 2,000 psi). The selection of an alternative is controlled by the depth and condition of the subgrade. The Geotechnical Engineer should be consulted to determine the proper selection.

Footing dimensions and reinforcing steel should also be observed. Concrete material should be sampled and tested for compressive strength, and placement operations should be monitored to record concrete slump, temperature, and age at time of placement. Concrete batch tickets should be provided by the supplier so that water-cement ratios and cement content can be checked and documented.


19

EXCAVATIONS

Our comments on excavation are based on our experience in the project vicinity and examination of the recovered samples. Excavation depends on the contractor's equipment, capabilities, and experience. Therefore, it should be the contractor's responsibility to determine the most effective methods for excavation. The above comments are intended for informational purposes for the design team only and may be used to review the contractor's proposed excavation methods.

Excavations that will receive compacted fill should have vertical or benched sidewalls so that lifts of fill material will be placed and compacted on horizontal planes. Stockpiles of soil or materials, and heavy equipment should not be placed immediately above and adjacent to unbraced vertical excavation walls (trenches).

In Federal Register, Volume 54, No. 209 (October 1989), the United States Department of Labor, Occupational Safety and Health Administration (OSHA) amended its “Construction Standards for Excavations, 29 CFR, Part 1926, subpart P”. This document was issued to insure the safety of workmen entering trenches or excavations.

It is mandated by this federal regulation that all excavations such as utility trenches, basement excavation, or footing excavations be constructed in accordance with the new OSHA guidelines. These regulations are enforced.

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

We are providing this information solely as a service to our client. ECS does not assume responsibility for construction site safety or the contractor’s or other party’s compliance with local, state, and federal regulations.


20

LIMITATIONS

This report has been prepared to aid in the evaluation of subsurface conditions at this site and to assist design professionals in the geotechnical related design of this project. It is intended for use with regard to the specific project as described in this report. Any substantial changes or differences in understood building loads, building and pavement layouts, understood finished floor elevation, or understood site grading should be brought to our attention so that we may determine any effect on the recommendations provided in this report. It is recommended that all construction operations dealing with earthwork and foundations be reviewed by an experienced Geotechnical Engineer to provide information on which to base a decision as to whether the design requirements are fulfilled in the actual construction.

The opinions and conclusions expressed in this report are those of ECS and represent interpretation of the subsurface conditions based on tests and the results of our analyses. ECS is not responsible for the interpretation or implementation by others of recommendations provided in this report. This report has been prepared in accordance with generally accepted principles of geotechnical engineering practice and no warranties are included, expressed, or implied, as to the professional services provided under the terms of our agreement.

The analysis and recommendations submitted in this report are based upon the data obtained from the test borings performed at the locations indicated in the test boring location plan, and from other information described in this report. This report does not reflect any variations that may occur around the test borings. In the performance of the subsurface exploration, specific information is obtained at specific locations at specific times. However, it is a well known fact that variations in soil conditions and depth to rock exist on most sites between test boring locations, and conditions such as groundwater levels vary from time to time. The nature and extent of variations may not become evident until the course of construction. If variations then appear evident, after allowing ECS to perform on-site observations during the construction period and note characteristics and variations, a re-evaluation of the recommendations in this report will be necessary.

The client should consider including a “changed conditions” clause in the contract documents. Such a clause might permit contractors to provide a lower bid since they can consider lower costs to account for contingencies. The client should consider including an arbitration procedure in the contract documents for situations when the owner, contractor, and design professionals do not agree on the changed conditions and their effects at the moment they are disclosed.

FIGURES

Figure 1: Site Location Plan

Figure 2: Regional Geology Map

Figure 3: Boring Location Diagram

EC

S-T

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21

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FIG

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5

PM

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FIG

1:

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41

3 In

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Google Earth Imagery Date: October 2, 2014

Project Site

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20

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, S

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s 7

875

8

PR

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No.:

17

- 4

312

FIG

UR

E: C

FR

SC

ALE

: N

TS

DA

TE

: JU

LY

20

15

PM

:MS

FIG

2:

Reg

ion

al

Ge

olo

gy M

ap

Ke

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Mu

ltifa

mily

Deve

lop

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nt

10

41

3 In

ters

tate

35

Sou

th

Au

stin

, T

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Qtt – Tributary Terrace Deposits Qal – Alluvium

Kta – Taylor Group Geologic Atlas of Texas – Austin Sheet, Department of Economic Geology University

of Texas at Austin, Reprinted 1992

Project Location

EC

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AS

, L

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21

20

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s 7

875

8

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No.:

17

-43

12

FIG

UR

E: C

FR

SC

ALE

: N

TS

DA

TE

: J

UL

Y 2

015

PM

:MS

FIG

3:

Bo

rin

g L

oca

tio

n D

iag

ram

Ke

esee

Multifa

mily

Deve

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10

41

3 In

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35

Sou

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APPENDIX

Test Boring Logs

Reference Notes for Boring Logs

USCS Information

Lab Testing Summary

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

ST

ST

ST

ST

ST

ST

ST

RC

24

24

24

24

24

24

24

54

24

24

24

24

24

24

24

32

(CH) FAT CLAY WITH SAND, Dark Brown toBrown, Very Stiff

(CL) SANDY LEAN CLAY, Light Brown, VeryStiff to Stiff

-Becoming Soft

LIMESTONE, Off-White, Very Hard, AustinChalk Formation

END OF BORING @ 25.00'

3.0

7724

26.9 3.5

4.0

4.5

28

18

13.11.5

2819

20.0

2.0

.5

0 59

CLIENT

Ardent Residential

JOB #

4238

BORING #

P-1

SHEET

PROJECT NAME

Keesee Multifamily Development

ARCHITECT-ENGINEER

SITE LOCATION

10413 IH-35 S, Austin, TexasNORTHING EASTING STATION

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN-SITU THE TRANSITION MAY BE GRADUAL.

WL None WS WD BORING STARTED 02/25/15 CAVE IN DEPTH

WL(BCR) WL(ACR) BORING COMPLETED 02/25/15 HAMMER TYPE

WL RIG CME 75 FOREMAN Antonio DRILLING METHOD Air, ST, RC AirDRILLING METHOD Air, ST, RC Air

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION

DESCRIPTION OF MATERIAL

WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS

BOTTOM OF CASING LOSS OF CIRCULATION

CALIBRATED PENETROMETER TONS/FT2

PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %

ROCK QUALITY DESIGNATION & RECOVERY

RQD% REC.%

STANDARD PENETRATIONBLOWS/FT

1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

ST

ST

ST

ST

ST

SS

RC

SS

24

24

24

24

24

17

60

18

24

24

24

24

24

17

0

18

(CH) FAT CLAY, Dark Brown, with Some Sand,Very Stiff

(CL) SANDY LEAN CLAY, Light Brown, VeryStiff

MARL, Light Brown, Very Hard

(CH) FAT CLAY, Brown with Mottled Gray, VeryStiff


2241

50/5

61118

8025

36.7 4.0

4.5

4.5

2718

18.5 4.5

4.5

91/11

0

0

29

CLIENT

Ardent Residential

JOB #

4238

BORING #

P-2

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION





WL RIG CME 75 FOREMAN Antonio DRILLING METHOD Auger, Air, ST, SS, RC AirDRILLING METHOD Auger, Air, ST, SS, RC Air

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

ST

ST

SS

SS

SS

SS

SS

SS

24

24

18

18

18

18

0

11

24

24

18

18

18

18

0

11

(CH) FAT CLAY WITH SAND, Dark Brown,Very Stiff

(CL) SANDY LEAN CLAY, Light Brown, Stiff

(SC) CLAYEY SAND, Light Brown, MediumDense

(CL) SANDY LEAN CLAY, Light Brown, Stiff

MARL, Light Gray, Very Hard


575

558

61014

778

50/0

3650/5

4.5

4.5

12

13 13.6

24

15

50/0

50/5

CLIENT

Ardent Residential

JOB #

4238

BORING #

P-3

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION



WL 22.5 WS WD BORING STARTED 02/24/15 CAVE IN DEPTH


WL RIG CME 75 FOREMAN Antonio DRILLING METHOD Air, ST, SSDRILLING METHOD Air, ST, SS

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

ST

ST

ST

SS

SS

SS

SS

SS

24

24

24

18

18

17

2

1

24

24

24

18

18

17

2

1

(CH) FAT CLAY WITH SAND, Dark Brown toBrown, Very Stiff

(CL) SANDY LEAN CLAY with Some Gravel,Brown, Very Stiff

(SC) CLAYEY SAND, Light Brown to Brown,Medium Dense

- Becoming Very Dense

CHALKY LIMESTONE, Off-White to Tan, VeryHard


9109

101215

724

50/5

50/2

50/1

3.5

4.5

27

18

13.7

4.5

19

278.4

74/11

50/2

50/1

CLIENT

Ardent Residential

JOB #

4238

BORING #

P-4

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION





WL RIG CME 75 FOREMAN Antonio DRILLING METHOD Air, SS, STDRILLING METHOD Air, SS, ST

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

ST

ST

ST

24

24

24

24

24

18

24

24

24

24

24

18

(CH) FAT CLAY, Dark Brown to OrangishBrown, Stiff to Very Stiff

(CL) SANDY LEAN CLAY, Brown, Very Stiff

(SC) CLAYEY SAND, Brown, Medium Dense

END OF BORING @ 15'

71013

71013

61

18

35.2

1.5

3.5

3.5

14.7 3.5

232712

12.4 4

21

11

14.2

4

2315.5

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-1

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION

10413 Interstate 35 South, Austin, TXNORTHING EASTING STATION



WL(BCR) WL(ACR) BORING COMPLETED 06/26/15 HAMMER TYPE Auto

WL RIG CME 75 FOREMAN Tony DRILLING METHOD Auger, SS, STDRILLING METHOD Auger, SS, ST

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

SS

SS

SS

24

24

24

18

18

4

24

24

24

18

18

4

(CH) FAT CLAY, Dark Brown to Brown, Stiff toVery Stiff

(CL) SANDY LEAN CLAY, Brown, Very Stiff

(CL) LEAN CLAY, Brown, Hard, gravelly nearbottom

Marl, Light Brown, Very Hard

END OF BORING @ 15'

81027

142227

50/4

1.5

601725.2 4

401320 3.0

37

49

50/45.9

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-2

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION





WL RIG CME 75 FOREMAN Tony DRILLING METHOD Auger, ST, SSDRILLING METHOD Auger, ST, SS

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

ST

ST

ST

ST

24

24

24

24

24

24

24

24

24

24

24

24

(CH) FAT CLAY, Dark Brown to Brown, Stiff toVery Stiff

(SC) CLAYEY SAND WITH GRAVEL, Brown,Medium Dense

(CL) LEAN CLAY WITH SAND, Light Brown,Very Stiff

(SC) CLAYEY SAND, Tan, Medium Dense

(CL) LEAN CLAY, Tan, Stiff

END OF BORING @ 15'

71

20

31.1

2.0

541521.8 4.0

12.4 3.5

2614

14.4 4.0

12.81.0

24

12

10.2

2

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-3

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION





WL RIG CME 75 FOREMAN Tony DRILLING METHOD Auger, STDRILLING METHOD Auger, ST

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

ST

ST

SS

24

24

24

24

24

18

24

24

24

24

24

18

(CH) FAT CLAY, Dark Brown to ReddishBrown, Stiff

(CH) GRAVELLY FAT CLAY, Dark Brown toReddish Brown, Very Stiff

(SC) CLAYEY SAND, Light Brown to Tan,Medium Dense

(GC) CLAYEY GRAVEL WITH SAND, TanYellowish, Dense

END OF BORING @ 15'

151627

70242.8

1.5

711732.82

551427.9 4

14.31.0

436.1

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-4

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION






DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

ST

SS

SS

24

24

24

24

18

18

24

24

24

24

18

18

(CH) FAT CLAY, Dark Brown, Stiff

(SC) CLAYEY SAND, Light Brown to Orange,Medium Dense to Dense

(SC) CLAYEY SAND WITH GRAVEL, Tan toOrange, Very Dense

END OF BORING @ 15'

81417

204040

33.7

2.5

2

13.6 2

1

31

809.1

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-5

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION






DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

S-1

S-2

S-3

S-4

S-5

S-6

ST

ST

ST

ST

SS

SS

24

24

24

24

18

18

24

24

24

24

18

18

(CH) FAT CLAY, Dark Brown,Stiff

(CL/SC) SANDY LEAN CLAY/CLAYEY SAND,Brown, Stiff

(SC) CLAYEY SAND, Light Brown to Tan,Medium Dense to Dense

(SC) CLAYEY SAND WITH GRAVEL, Tan toOrange, Dense

END OF BORING @ 15'

141721

272524

7120

34.9

3.5

3

3913

14.9 2.5

12.72

38

499.8

CLIENT

Ardent Residential

JOB #

17:4312

BORING #

B-6

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION






DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

REFERENCE NOTES FOR BORING LOGS I. Drilling Sampling Symbols

SS Split Spoon Sampler ST Shelby Tube Sampler RC Rock Core, NX, BX, AX PM Pressuremeter DC Dutch Cone Penetrometer RD Rock Bit Drilling BS Bulk Sample of Cuttings PA Power Auger (no sample) HSA Hollow Stem Auger WS Wash sample REC Rock Sample Recovery % RQD Rock Quality Designation %

II. Correlation of Penetration Resistances to Soil Properties

Standard Penetration (blows/ft) refers to the blows per foot of a 140 lb. hammer falling 30 inches on a 2-inch OD split-spoon sampler, as specified in ASTM D 1586. The blow count is commonly referred to as the N-value.

A. Non-Cohesive Soils (Silt, Sand, Gravel and Combinations)

Density Relative Properties Under 4 blows/ft Very Loose Adjective Form 12% to 49% 5 to 10 blows/ft Loose With 5% to 12%

11 to 30 blows/ft Medium Dense 31 to 50 blows/ft Dense Over 51 blows/ft Very Dense

Particle Size Identification

Boulders 8 inches or larger Cobbles 3 to 8 inches Gravel Coarse 1 to 3 inches Medium ½ to 1 inch Fine ¼ to ½ inch Sand Coarse 2.00 mm to ¼ inch (dia. of lead pencil) Medium 0.42 to 2.00 mm (dia. of broom straw) Fine 0.074 to 0.42 mm (dia. of human hair) Silt and Clay 0.0 to 0.074 mm (particles cannot be seen)

B. Cohesive Soils (Clay, Silt, and Combinations)

Blows/ft Consistency Unconfined

Comp. Strength Qp (tsf)

Degree of Plasticity

Plasticity Index

Under 2 Very Soft Under 0.25 None to slight 0 – 4 3 to 4 Soft 0.25-0.49 Slight 5 – 7 5 to 8 Medium Stiff 0.50-0.99 Medium 8 – 22

9 to 15 Stiff 1.00-1.99 High to Very High Over 22 16 to 30 Very Stiff 2.00-3.99 31 to 50 Hard 4.00–8.00 Over 51 Very Hard Over 8.00

III. Water Level Measurement Symbols

WL Water Level BCR Before Casing Removal DCI Dry Cave-In WS While Sampling ACR After Casing Removal WCI Wet Cave-In WD While Drilling Est. Groundwater Level Est. Seasonal High GWT

The water levels are those levels actually measured in the borehole at the times indicated by the symbol. The measurements are relatively reliable when augering, without adding fluids, in a granular soil. In clay and plastic silts, the accurate determination of water levels may require several days for the water level to stabilize. In such cases, additional methods of measurement are generally applied.

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D 2487)

Major Divisions Group

Symbols Typical Names Laboratory Classification Criteria

GW

Well-graded gravels, gravel-sand mixtures, little or no

fines

Cu = D60/D10 greater than 4

Cc = (D30)2/(D10xD60) between 1 and 3

Cle

an g

ravels

(L

ittle o

r no

fines)

GP

Poorly graded gravels, gravel-sand mixtures, little or

no fines

Not meeting all gradation requirements for GW

d

GMa

u

Silty gravels, gravel-sand mixtures

Atterberg limits below “A” line or P.I. less than 4

Gra

vels

(M

ore

than h

alf o

f coars

e fra

ction is

larg

er

than N

o. 4 s

ieve s

ize)

Gra

vels

with fin

es

(Appre

cia

ble

am

ount of

fines)

GC

Clayey gravels, gravel-sand-clay mixtures

Atterberg limits below “A” line or P.I. less than 7

Above “A” line with P.I.

between 4 and 7 are borderline cases requiring use of dual symbols

SW

Well-graded sands, gravelly sands, little or no fines

Cu = D60/D10 greater than 6 Cc = (D30)

2/(D10xD60) between 1 and 3

Cle

an s

ands

(Little o

r no

fines)

SP

Poorly graded sands, gravelly sands, little or no fines

Not meeting all gradation requirements for SW

d

SMa

u

Silty sands, sand-silt mixtures

Atterberg limits above “A” line

or P.I. less than 4

Coars

e-g

rain

ed s

oils

(M

ore

than h

alf o

f m

ate

rial is

larg

er

than N

o. 200 S

ieve s

ize)

Sands

(More

than h

alf o

f coars

e fra

ction is

sm

alle

r th

an N

o. 4 s

ieve s

ize)

Sands w

ith fin

es

(Appre

cia

ble

am

ount o

f

fines)

SC

Clayey sands, sand-clay mixtures

Dete

rmin

e p

erc

enta

ges o

f sand a

nd g

ravel fr

om

gra

in-s

ize c

urv

e.

Dependin

g o

n p

erc

enta

ge o

f fines (

fraction s

malle

r th

an

No. 200 s

ieve s

ize),

coars

e-g

rain

ed s

oils

are

cla

ssifie

d a

s follo

ws:

Less than 5

perc

ent

GW

, G

P, S

W, S

P

More

than 1

2 p

erc

ent

G

M, G

C, S

M, S

C

5 to 1

2 p

erc

ent B

ord

erl

ine c

ases r

equirin

g d

ual sym

bols

b

Atterberg limits above “A” line with P.I. greater than 7

Limits plotting in CL-ML zone with P.I. between 4 and 7 are borderline

cases requiring use of dual symbols

ML

Inorganic silts and very fine sands, rock flour, silty or clayey fine sands, or clayey

silts with slight plasticity

CL

Inorganic clays of low to medium plasticity, gravelly

clays, sandy clays, silty clays, lean clays

Silt

s a

nd c

lays

(Liq

uid

lim

it less than 5

0)

OL Organic silts and organic silty

clays of low plasticity

MH

Inorganic silts, micaceous or

diatomaceous fine sandy or silty soils, elastic silts

CH

Inorganic clays of high plasticity, fat clays

Silt

s a

nd c

lays

(Liq

uid

lim

it g

reate

r th

an 5

0)

OH

Organic clays of medium to high plasticity, organic silts

Fin

e-g

rain

ed s

oils

(M

ore

than h

alf m

ate

ria

l is

sm

alle

r th

an N

o. 200 S

ieve)

Hig

hly

Org

anic

soils

Pt

Peat and other highly organic soils

Plasticity Chart

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70 80 90 100

Liquid Limit

Plas

ticity

Inde

x

"A" line

CH

MH and OH

CL

ML and OLCL-ML

a Division of GM and SM groups into subdivisions of d and u are for roads and airfields only. Subdivision is based on Atterberg limits; suffix d used when

L.L. is 28 or less and the P.I. is 6 or less; the suffix u used when L.L. is greater than 28. b Borderline classifications, used for soils possessing characteristics of two groups, are designated by combinations of group symbols. For example:

GW-GC, well-graded gravel-sand mixture with clay binder. (From Table 2.16 - Winterkorn and Fang, 1975)

P-1

S-2 2.00 - 4.00 26.9 CH 77 24 53

S-5 8.00 - 10.00 13.1 CL 28 18 10

S-6 13.00 - 15.00 20.0 CL 28 19 9

P-2

S-1 0.00 - 2.00 36.7 CH 80 25 55

S-4 6.00 - 8.00 18.5 CL 27 18 9

P-3

S-4 6.00 - 7.50 13.6 CL 60.3

P-4

S-3 4.00 - 6.00 13.7 CL 27 18 9

S-5 8.50 - 10.00 8.4 SC 33.1

Laboratory Testing Summary

Notes: 1. ASTM D 2216, 2. ASTM D 2487, 3. ASTM D 4318, 4. ASTM D 1140, 5. See test reports for test method, 6. See test reports for test method

Definitions: MC: Moisture Content, Soil Type: USCS (Unified Soil Classification System), LL: Liquid Limit, PL: Plastic Limit, PI: Plasticity Index, CBR: California Bearing Ratio, OC: Organic Content (ASTM D 2974)

Project No. 4238

Project Name: Keesee Multifamily Development

PM: M. Sorgenfrei

PE: R. Archer

Printed On: Monday, July 27, 2015

SampleSource

SampleNumber

Depth(feet)

MC1

(%)Soil

Type2 LL

Atterberg Limits3

PL PI

PercentPassingNo. 200Sieve4

MaximumDensity

(pcf)

Moisture - Density (Corr.)5

OptimumMoisture

(%)

CBRValue6 Other

Page 1 of 1

B-1

S-1 0.00 - 2.00 35.2 CH 61 18 43

S-3 4.00 - 6.00 14.7 CL 59.1

S-4 6.00 - 8.00 12.4 CL 27 12 15

S-5 8.00 - 10.00 14.2 CL 21 11 10

S-6 13.50 - 15.00 15.5 SC 47.0

B-2

S-2 2.00 - 4.00 25.2 CH 60 17 43

S-3 4.00 - 6.00 20 CL 40 13 27

S-6 13.50 - 13.83 5.9 SC 27.8

B-3

S-1 0.00 - 2.00 31.1 CH 71 20 51

S-2 2.00 - 4.00 21.8 CH 54 15 39

S-3 4.00 - 6.00 12.4 SC 31.4

S-4 6.00 - 8.00 14.4 CL 26 14 12

S-5 8.00 - 10.00 12.8 SC 43.1

S-6 13.50 - 15.50 10.2 CL 24 12 12

B-4

S-1 0.00 - 2.00 2.8 CH 70 24 46

S-2 2.00 - 4.00 32.8 CH 71 17 54

S-3 4.00 - 6.00 27.9 CH 55 14 41

S-4 6.00 - 8.00 14.3 SC 41.1

S-6 13.50 - 15.00 6.1 GC 13.6

B-5

S-1 0.00 - 2.00 33.7 CH

S-3 4.00 - 6.00 13.6 SC 38.1

S-6 13.50 - 15.00 9.1 SC 20.7

B-6




Project No. 17:4312


PM:

PE:


SampleSource

SampleNumber

Depth(feet)

MC1

(%)Soil

Type2 LL

Atterberg Limits3

PL PI


MaximumDensity

(pcf)


OptimumMoisture

(%)

CBRValue6 Other

Page 1 of 2

S-1 0.00 - 2.00 34.9 CH 71 20 51

S-3 4.00 - 6.00 14.9 CL/SC 39 13 26

S-4 6.00 - 8.00 12.7 SC 36.9

S-6 13.50 - 15.00 9.8 SC 24.1




Project No. 17:4312


PM:

PE:


SampleSource

SampleNumber

Depth(feet)

MC1

(%)Soil

Type2 LL

Atterberg Limits3

PL PI


MaximumDensity

(pcf)


OptimumMoisture

(%)

CBRValue6 Other

Page 2 of 2

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