3-4. Parking Lot (GEO Report) - signed (RFP 26-029C).pdf

Report Cover Page

SCUCISD Parking Lot Geotechnical Engineering Report

Schertz, Texas

July 28, 2026 | Terracon Project No. 1000028512

Prepared for:

Schertz Cibolo Universal City ISD

1060 Elbel Road

Schertz, TX 78154

6000 Northwest Parkway, Suite 100

San Antonio, Texas 78249

P (210) 641 2112

Terracon.com

Facilities | Environmental | Geotechnical | Materials

Report Cover Letter to Sign

July 28, 2026

Schertz Cibolo Universal City ISD

1060 Elbel Road

Schertz, TX 78154

Attn: Mr. J.D. Mosley

P: (210) 945-6206

E: jmosley@scucisd.org

Re: Geotechnical Engineering Report

SCUCISD Parking Lot

1001 Elbel Road

Schertz, Texas

Terracon Project No. 1000028512

Dear Mr. Mosley:

We have completed the scope of Geotechnical Engineering services for the above referenced project in general accordance with Terracon Proposal No. 1000013324 dated

June 4, 2026. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of a new parking lot for the proposed project.

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

Sincerely, Terracon

(Firm Registration: F3272)

Carlos Cotilla Arin Barkataki, P.E.

Senior Staff Engineer Principal

Geotechnical Engineering Report

SCUCISD Parking Lot | Schertz, Texas

Facilities | Environmental | Geotechnical | Materials i

Table of Contents

Introduction Project Description Site Conditions Geotechnical Characterization Geotechnical Overview

Expansion Potential Sulfate Testing Demolition Considerations

Earthwork General Site Preparation Pavement Subgrade Preparation Fill Material Types Fill Placement and Compaction Requirements Earthwork Construction Considerations

Pavements Subgrade Preparation Design Recommendations Pavement Section Materials Pavement Joints and Reinforcement

General Comments

Facilities | Environmental | Geotechnical | Materials ii

Figures GeoModel

Attachments

Exploration and Testing Procedures Site Location and Exploration Plans

Exploration and Laboratory Results

Supporting Information

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

Refer to each individual Attachment for a listing of contents.

http://client.terracon.com/ http://client.terracon.com/

Facilities | Environmental | Geotechnical | Materials 1

Introduction

This report presents the results of our subsurface exploration and Geotechnical

Engineering services performed for the proposed parking lot to be located at 1001 Elbel

Road in Schertz, Texas within Samuel Clemens High School. The purpose of these services was to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil conditions

■ Groundwater conditions

■ Site preparation and earthwork

■ Pavement design and construction

The geotechnical engineering Scope of Services for this project included the advancement of four (4) test borings to depths about 10 feet below existing grades.

Drawings showing the site and boring locations are shown on the Site Location and

Exploration Plan, respectively. The results of the laboratory testing performed on soil samples obtained from the site during our field exploration are included on the boring logs in the Exploration Results section.

Project Description

Our initial understanding of the project was provided in our proposal and was discussed during project planning. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows:

Item Description

Information

Provided

We have been provided the pertinent project details by Mr.

Garrett Martin with AGCM via an email dated May 27, 2026.

Project

Description

We understand that new pavements and driveway areas will be constructed at the existing Samuel Clemens High School.

Grading/Slopes

Not available at the time of this report. However, based on the

Google Earth© image up to approximately +/-2 of cut/fill may be required to establish the proposed site grades.

Facilities | Environmental | Geotechnical | Materials 2

Item Description

Pavements

Both rigid (concrete) and flexible (asphalt) pavement sections will be considered. Traffic load was not provided at the time of this report. In the absence of specific traffic loading data, typical pavement design parameters will be considered. We understand lime and cement stabilization of the subgrade will be considered.

Geogrid will also be considered beneath the proposed pavements.

Terracon should be notified if any of the above information is inconsistent with the planned construction, especially the grading limits, as modifications to our recommendations may be necessary.

Site Conditions

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

Item Description

Parcel

Information

The project is located at 1001 Elbel Road in Schertz, Texas within

Samuel Clemens High School.

See Site Location

Existing

Improvements

The proposed pavement areas appear to be undeveloped based on available aerial imagery. Some existing pavements may be removed and replaced to allow for the construction of the new parking lot and driveway areas.

Current Ground

Cover Bare soil and grass.

Existing

Topography

Based on Google Earth, the site slopes from El. 703 feet to El.

702 feet.

Geotechnical Characterization

We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of the site. Conditions observed at each exploration point are indicated on the individual logs. The individual logs can be found in the Exploration Results and the GeoModel can be found in the Figures attachment of this report.

Facilities | Environmental | Geotechnical | Materials 3

As part of our analyses, we identified the following model layers within the subsurface profile. For a more detailed view of the model layer depths at each boring location, refer to the GeoModel.

Model Layer Layer Name General Description

1 Clay (CH and CL) 1,2

Dark Brown, Light Brown; Stiff to

Hard

2 Sand (SC)

Light Brown; Medium Dense to

Dense

1. The FAT CLAY (CH) materials could undergo high to very high volumetric changes

(shrink/swell) should they experience changes in their in-place moisture content.

2. The LEAN CLAY (CL) materials could undergo moderate volumetric changes (shrink/swell) should they experience changes in their in-place moisture content.

3. The CLAYEY SAND (SC) materials could undergo low volumetric changes (shrink/swell) should they experience changes in their in-place moisture content. These materials are considered volumetrically stable with regards to change in moisture content due to their granular nature. Encountered in Boring B-3 and B-4 only.

Geotechnical Overview

Expansion Potential

Expansive soils are present at this site. The near surface, high plasticity fat clay could become unstable with typical earthwork and construction traffic, especially after precipitation events. Effective drainage should be completed early in the construction sequence and maintained after construction to avoid potential issues. If possible, the grading should be performed during the warmer and drier times of the year. If grading is performed during the winter months, an increased risk for possible undercutt ing and replacement of unstable subgrade will persist.

Based on our findings, the subsurface soils at this site generally exhibit high shrink/swell potential. Based on information developed from our field and laboratory programs, on information from nearby projects and on method TEX-124-E of the Texas Department of

Transportation (TxDOT) Manual of Testing Procedures, we estimate the subgrade soils at the site exhibit a Potential Vertical Rise (PVR) of about 2 to 2½ inches in their present condition. It can be emphasized that the actual movements could be greater than the estimated values because of inadequate drainage, ponded water and moisture infiltration beneath the pavement after construction.

Due to the presence of the expansive clay soil at the site, some pavement movement should be expected.

Facilities | Environmental | Geotechnical | Materials 4

Sulfate Testing

Sulfate tests were performed on selected soil samples collected from the project site to check for a possible adverse reaction with concrete. Testing was not performed at all depths.

The sulfate content concentration for the samples tested along with the location and approximate depths are as follows:

Boring Sample Depth (feet) Sulfate Content (percent by mass)

B-1 2.5-4 0.0042

B-4 0-1.5 0.0043

The American Concrete Institute (ACI) and the Texas Department of Transportation

(TxDOT) provide guidance and specifications regarding sulfates in soil and groundwater.

Water Soluble Sulfate Content in Soil

(percent by mass) Severity of Potential Exposure

> 2.00 Class S3

0.2 - 2.0 Class S2

0.1-0.2 Class S1

<0.10 Class S0

Based on the test results, the severity of potential exposure of concrete to sulfate attack falls under Class S0.

Demolition Considerations

Some demolitions of existing structures may be necessary to accommodate the new pavements at this site. As a result, abandoned (or to be abandoned) underground utilities may be present within the footprint area of the planned structures. Utilities and associated backfill and granular bedding material can provide avenues for subsurface water to enter under the structure subgrade. We recommend that all abandoned utility lines be completely removed from the proposed structure areas. Abandoned pipes which remain underground should be grouted.

Any below-grade foundation or utility structures removal associated with demolition will likely create large subsurface voids. It is very important that all subsurface voids formed from the removal of the foundation system be backfill completely with moisture conditioned, compacted, engineered fill as described in the Earthwork section of this

Facilities | Environmental | Geotechnical | Materials 5 report. It is our experience that improperly backfilled excavations can cause significant settlement under and around the proposed structures.

As an alternative to compacted soil backfill, a flowable fill material may be considered.

Flowable fill, or slurry, when properly designed provides a competent subgrade and can still be readily excavated if the utilities require repair or maintenance. In addition, flowable fill does not need to be placed in lifts, compacted, or tested.

Earthwork

Earthwork is anticipated to include clearing and grubbing, excavations, and engineered fill placement. The following sections provide recommendations for use in the preparation of specifications for the work. Recommendations include critical quality criteria, as necessary, to render the site in the state considered in our geotechnical engineering evaluation for foundations, and pavements.

General Site Preparation

We understand that a new parking lot will be constructed. Prior to construction, the work area should be cleared of any vegetation, existing pavements and any unsuitable materials. After stripping and grubbing, the exposed subgrade should be proof-rolled where possible to aid in locating loose or soft areas. Proof-rolling can be performed with a fully loaded dump truck or comparable pneumatic tired vehicle. Soils that are observed to rut or deflect excessively (typically greater than 1-inch) under the moving load should be overexcavated to provide a firm, uniform bearing layer. The proof rolling and overexcavation activities should be witnessed by a representative of the Geotechnical

Engineer and should be performed during a period of dry weather. Subgrade stabilization may also be performed as described below if the exposed subgrade exhibits yielding or pumping under construction traffic.

■ Removal and replacement with select fill.

■ Chemical treatment of the soil to dry and increase the stability of the subgrade.

■ Drying by natural means if the schedule allows.

Pavement Subgrade Preparation

As previously stated, we estimate that the subsurface soils at the proposed project site exhibit a PVR of about 2 to 2½ inches in its present condition. Therefore, pavement movement up to 2½ inches should be expected. Subgrade preparation recommendations are provided below if heave potential is desired to be mitigated as per the table below.

Facilities | Environmental | Geotechnical | Materials 6

Fill Material Types

Fill Type USCS Classification Comments

Select Fill

CL, SC, GC

➢ LL≤40 and 7<PI≤20

➢ % passing #200 sieve ≥35%

➢ Maximum particle size 1½”

Note 1

Onsite Soils CL, CH, SC Note 2.

1/ Prior to any filling operations, samples of the proposed Select Fill and on-site materials should be obtained for laboratory moisture-density testing. The tests will provide a basis for evaluation of fill compaction by in-place density testing. A qualified soil technician should perform sufficient in-place density tests during the filling operations to ensure that proper levels of compaction, including dry unit weight and moisture content are attained.

2/ Onsite soils should not be used as Select Fill.

Fill Placement and Compaction Requirements

Item Requirements

Fill Lift Thickness

All fill should be placed in thin, loose lifts of about

8 inches, with compacted thickness not exceeding

6 inches for compaction with regular equipment. For handheld equipment, loose lifts should be 6 inches, with compacted thickness not exceeding 4 inches

Compaction of Onsite Soil and

Select Fill

95 percent of the material’s Standard Proctor maximum dry density (ASTM D 698)

Moisture Content of On-Site

Soil and Select Fill

Between -2 and +3 percentage points of the optimum moisture content.

Earthwork Construction Considerations

It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Based upon the subsurface conditions determined from the geotechnical exploration, subgrade soils exposed during construction are

Potential Vertical Rise (PVR) (inch) Select Fill Thickness (feet)

1 4

1½ 3

2 2

Facilities | Environmental | Geotechnical | Materials 7 anticipated to be relatively stable. However, the stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Over excavation of wet zones and replacement with granular materials may be necessary.

As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part

1926, Subpart P, “Excavations” and its appendices, and in accordance with any applicable local and/or state regulations.

Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety or the contractor's activities; such responsibility shall neither be implied nor inferred.

Excavations or other activities resulting in ground disturbance have the potential to affect adjoining properties and structures. Our scope of services does not include review of available final grading information or consider potential temporary grading performed by the contractor for potential effects such as ground movement beyond the project limits. A preconstruction/ precondition survey should be conducted to document nearby property/infrastructure prior to any site development activity. Excavation or ground disturbance activities adjacent or near property lines should be monitored or instrumented for potential ground movements that could negatively affect adjoining property and/or structures.

Pavements

Both flexible and rigid pavement systems may be considered for the project. Based on our knowledge of the project, we anticipate that traffic loads will be produced primarily by automobile traffic, school buses, delivery and trash removal trucks.

Subgrade Preparation

Prior to construction, any vegetation and any otherwise unsuitable materials should be removed from the new pavement areas. After stripping, the subgrade should be proof-rolled where possible to aid in locating loose or soft areas. Proof-rolling can be performed with a fully loaded dump truck. Wet, soft, low-density or dry material should either be removed or moisture conditioned and recompacted to the moisture contents and densities described in section Fill Placement and Compaction Requirements prior to placing fill.

Due to the presence of expansive clay soils, movement of the pavement up to 2½ inches should be anticipated. If the pavement movement is not tolerable, then pavement

Facilities | Environmental | Geotechnical | Materials 8 subgrade can be prepared as stated in the Pavement Subgrade Preparation section of the report.

Design Recommendations

For this project Light and Heavy pavement section alternatives have been provided. Light is for areas expected to receive only car traffic. Heavy assumes areas with heavy traffic, such as school bus loop, trash pickup areas, delivery areas and main access drive areas.

The flexible pavement section was designed in general accordance with the National

Asphalt Pavement Association (NAPA) Information Series (IS-109) method (Class 1 for

Light and Class 2 for Heavy). The rigid pavement section was designed using the American

Concrete Institute (ACI 330R-01) method (Traffic Category A (ADTT=1) for Light and A-1

(ADTT=10) for Heavy). If heavier traffic loading is expected, Terracon should be provided with the information and allowed to review these pavement sections.

Components

FLEXIBLE PAVEMENT SYSTEM (inches)

Raw Subgrade Modified Subgrade

Light

Duty

Heavy

Duty

Light

Duty

Heavy

Duty

Hot Mix Asphaltic Concrete 2.0 3.0 2.0 3.0

Granular Base Material 10.0 14.0 6.0 10.0

Lime/Cement Treated

Subgrade 1 --- --- 6.0 6.0

Moisture Conditioned Raw

Subgrade

6.0 6.0 --- ---

1/ In lieu of stabilized subgrade, Tensar HX 5.5 geogrid or similar can be used. The geogrid should be placed atop the prepared subgrade.

Facilities | Environmental | Geotechnical | Materials 9

Components

RIGID PAVEMENT SYSTEM (inches)

Raw Subgrade Modified Subgrade

Light

Duty

Heavy

Duty

Light

Duty

Heavy

Duty

Reinforced Concrete 5.5 7.0 5.0 6.5

Lime/Cement Treated

Subgrade --- --- 6.0 6.0

Moisture Conditioned Raw

Subgrade

6.0 6.0 --- ---

1/ Dumpster pad should be constructed as heavy-duty rigid section.

Pavement areas that will be subjected to heavy wheel and traffic volumes, such as waste bin or "dumpster" areas, entrance/exit ramps, and delivery areas, should be a heavy-duty rigid pavement section constructed of reinforced concrete. The concrete pavement areas should be large enough to properly accommodate the vehicular traffic and loads. For example:

◼ The dumpster pad should be large enough so that the wheels of the collection truck are entirely supported on the concrete pavement during lifting of the waste bin;

and

◼ The concrete pavement should extend beyond any areas that require extensive turning, stopping, and maneuvering.

◼ The pavement design engineer should consider these and other similar situations when planning and designing pavement areas. Waste bin and other areas that are not designed to accommodate these situations often result in localized pavement failures.

Pavement Section Materials

Presented below are selection and preparation guidelines for various materials that may be used to construct the pavement sections. Submittals should be made for each pavement material. The submittals should be reviewed by the Geotechnical Engineer and appropriate members of the design team and should provide test information necessary to verify full compliance with the recommended or specified material properties.

◼ Hot Mix Asphaltic Concrete Surface Course - The asphaltic concrete surface course should be plant mixed, hot laid Type C or D Surface. Each mix should meet the master specifications requirements of TXDOT SS 3076 and specific criteria for the job mix formula.

Facilities | Environmental | Geotechnical | Materials 10

◼ Concrete - Concrete should have a minimum 28-day design compressive strength of 4,000 psi.

◼ Granular Base Material - Base material may be composed of crushed limestone base meeting all of the requirements of 2024 TxDOT Item 247, Type A, Grade 1-2;

including triaxial strength. The material should be compacted to at least 95 percent of the maximum dry density as determined in accordance with ASTM D 1557 at moisture contents ranging from -2 and +3 percentage points of the optimum moisture content.

◼ Lime Treated Subgrade - Due to the presence of clay at this site, the subgrade may be modified with hydrated lime in accordance with TxDOT Item 260 in order to improve its strength and improve its load carrying capacity. We anticipate that approximately 6 to 8 percent hydrated lime will be required. This is equivalent to about 30 to 40 pounds of hydrated lime per square yard for a 6-inch treatment depth. However, the actual percentage should be determined by laboratory tests on samples of the clayey subgrade prior to construction. The optimum lime content should result in a soil-lime mixture with a pH of at least 12.4 when tested in accordance with ASTM C 977, Appendix XI and should reduce the Plasticity Index to 20 or less.

The lime should initially be blended with a mixing device such as a Pulvermixer, sufficient water added, and be allowed to cure for at least 48 hours. After curing, the lime-soil should be remixed to meet the in-place gradation requirements of

Item 260 and compacted to at least 95 percent of the maximum dry density determined in accordance with ASTM D 698 at moisture contents ranging from optimum and 4 percentage points above the optimum moisture content.

◼ Cement Treated Subgrade- The subgrade may be modified with cement in accordance with TxDOT Item 275, in order to improve its strength and improve its load carrying capacity.

For budgetary purposes, an application rate of 5 percent of maximum dry density as determined by the ASTM D698 for subgrade soils, or as required by the agency having jurisdiction, whichever is more stringent should be used. However, the final application rate should be determined based on the laboratory cement series

(Tex-120-E) testing performed on the samples of onsite soils blended with the cement proposed for construction. We anticipate about 25 pounds of cement per square yard (25lbs/sy) will be required for subgrade treatment.

Materials modified with cementitious slurry or Portland cement may not achieve their design strength if mixed at moisture contents greater than 2 percent above the optimum moisture content, or if not allowed to properly cure after placement due to the moisture content being less than 2 percentage points below the

Facilities | Environmental | Geotechnical | Materials 11 optimum moisture content. Therefore, it is important that the recommended moisture content of the modified zone be maintained within 2 percentage points of its optimum during the compaction and curing period. As a check, we recommend the moisture content be evaluated the day before the mixing operations and for at least 3 days after placement to confirm adequate moisture conditions. The cement-stabilized material should extend at least 2 feet beyond the edge of the area to be paved if possible. Soils mixed with cementitious slurry and Portland cement should be compacted and finished within 5 hours and 1.5 hours, respectively, after thoroughly mixing into the soil. The cement-treated subgrade should be compacted to at least 95 percent of the maximum dry density as determined by the standard proctor (ASTM D698).

◼ Moisture Conditioned Subgrade - The subgrade should be scarified to a depth of 6 inches and then moisture conditioned and compacted as recommended in the

Fill Compaction Requirements section of this report.

Details regarding subgrade preparation, fill materials, placement and compaction are presented in Earthwork section under subsections Fill Material Types and Fill

Placement and Compaction Requirements.

Pavement Joints and Reinforcement

The following is recommended for all concrete pavement sections in this report. Refer to

ACI 330 “Guide for Design and Construction of Concrete Parking Lots” for additional information.

Item Description

Distributed Reinforcing

Steel

No. 3 reinforcing steel bars at 18 inches on-center-each-way, Grade 60.

It is imperative that the distributed steel be positioned accurately in the pavement cross section, namely 2 inches from the top of the pavement.

Contraction Joint Spacing

12.5 feet each way for pavement thickness of 5 to

5.5 inches.

15 feet each way for pavement thickness of 6 inches or greater.

Saw cut control joints should be cut within 6 to 12 hours of concrete placement.

Contraction Joint Depth At least ¼ of pavement thickness.

Contraction Joint Width One-fourth inch or as required by joint sealant manufacturer.

Facilities | Environmental | Geotechnical | Materials 12

Item Description

Construction Joint Spacing To attempt to limit the quantity of joints in the pavement, consideration can be given to installing construction joints at contraction joint locations, where it is applicable.

Construction Joint

Depth/Width

Full depth of pavement thickness. Construct sealant reservoir along one edge of the joint. Width of reservoir to be ¼ inch or as required by joint sealant manufacturer. Depth of reservoir to be at least ¼ of pavement thickness.

Isolation Joint Spacing As required to isolate pavement from structures, etc.

Isolation Joint Depth Full depth of pavement thickness.

Isolation Joint Width ½ to 1 inch or as required by the joint sealant manufacturer.

Expansion Joint

In this locale, drying shrinkage of concrete typically significantly exceeds anticipated expansion due to thermal affects. As a result, the need for expansion joints is eliminated provided all joints (including saw cuts) are sealed. Construction of an unnecessary joint may be also become a maintenance problem.

All joints should be sealed. If all joints, including sawcuts, are not sealed then expansion joints should be installed.

All construction joints have dowels. Dowel information varies with pavement thickness as presented as follows:

Parameter 5 to 5½ inches 6 to 6½ inches 7 inches

Dowels ⅝ inch diameter ¾ inch diameter 1 inch diameter

Dowel Spacing 12 inches on center 12 inches on center 12 inches on center

Dowel Length 12 inches long 14 inches long 14 inches long

Dowel Embedment 5 inches 6 inches 6 inches

Facilities | Environmental | Geotechnical | Materials 13

Pavement Drainage and Maintenance

Pavements should be sloped to provide rapid drainage of surface water. Water allowed to pond on or adjacent to the pavements could saturate the subgrade and contribute to premature pavement deterioration. In addition, the pavement subgrade should be graded to provide positive drainage within the granular base section.

Long-term pavement performance will be dependent upon several factors, including maintaining subgrade moisture levels and providing for preventative maintenance. The following recommendations should be implemented to help promote long-term pavement performance:

◼ The subgrade and the pavement surface should be designed to promote proper surface drainage, preferably at a minimum grade of 2 percent.

◼ Install joint sealant and seal cracks immediately.

◼ Extend curbs into the subgrade for a depth of at least 3 inches to help reduce moisture migration into the subgrade soils beneath the pavement section.

◼ Place compacted, low permeability clayey backfill against the exterior side of the curb and gutter.

◼ Slope subgrade in landscape islands to low points should drain to an appropriate outlet.

◼ Edge drains are recommended along pavement/ landscape borders.

General Comments

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration.

Variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. Terracon should be retained as the Geotechnical

Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner

Facilities | Environmental | Geotechnical | Materials 14 is concerned about the potential for such contamination or pollution, other studies should be undertaken.

This report should be provided in its entirety to the key members of the design team, namely the Architect, Civil Engineer, and Structural. In addition, the MEP engineer, the

Landscape Architect, and others should be provided a copy as there may be geotechnical recommendations included herein related to their services.

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

Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly affect excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing. Site safety and cost estimating including excavation support and dewatering requirements/design are the responsibility of others. Construction and site development have the potential to affect adjacent properties. Such impacts can include damages due to vibration, modification of groundwater/surface water flow during construction, foundation movement due to undermining or subsidence from excavation, as well as noise or air quality concerns. Evaluation of these items on nearby properties are commonly associated with contractor means and methods and are not addressed in this report. The owner and contractor should consider a preconstruction/precondition survey of surrounding development. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

Figures

Contents:

GeoModel

-1

D E

P T H

B E

L O

W G

R A

D E

F e e t)

Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project.

Numbers adjacent to soil column indicate depth below ground surface.

NOTES:

B-1 B-2 B-3 B-4

Legend

This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.

GeoModel

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512

SCUCISD Clemens HS Parking Lot Addition

6000 Northwest Pkwy Ste San Antonio, TX

Fat Clay Lean Clay

Clayey Sand

Model Layer Layer Name General Description

1 Dark Brown, Light Brown; Stiff to Hard

2 Light Brown; Medium Dense to Dense

Clay

Sand

Attachments

Exploration and Testing Procedures

Field Exploration

Number of Borings Approximate Boring Depth (feet) Location

4 10 Pavement Area

Boring Layout and Elevations: Terracon personnel provided the boring layout using handheld GPS equipment (estimated horizontal accuracy of about ±10 feet) and referencing existing site features. If elevations and a more precise boring layout are desired, we recommend borings be surveyed.

Subsurface Exploration Procedures: We advanced the borings with a truck-mounted, drill rig using continuous flight augers (solid stem and/or hollow stem, as necessary, depending on soil conditions). Five samples were obtained in the upper 10 feet of each boring and at intervals of 5 feet thereafter. In the thin-walled tube sampling procedure, a thin-walled, seamless steel tube with a sharp cutting edge was pushed hydraulically into the soil to obtain a relatively undisturbed sample. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths.

A 3-inch O.D. split-barrel sampling spoon with 2.5-inch I.D. ring lined sampler was used for soil sampling. For safety purposes, all borings were backfilled with auger cuttings after the groundwater observations were completed.

We also observed the boreholes while drilling and at the completion of drilling for the presence of groundwater. Groundwater was not observed at these times in the boreholes.

The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs included visual classifications of the materials observed during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory.

Laboratory Testing

The project engineer reviewed the field data and assigned laboratory tests. The laboratory testing program included the following types of tests:

■ Moisture Content

■ Atterberg Limits

■ Grain Size Analysis

■ Sulfate Content

The laboratory testing program often included examination of soil samples by an engineer.

Based on the results of our field and laboratory programs, we described and classified the soil samples in accordance with the Unified Soil Classification System.

Site Location and Exploration Plans

Site Location Plan

Exploration Plan

Note: All attachments are one page unless noted above.

Site Location

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

Exploration Plan

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

Exploration and Laboratory Results

Boring Logs

Atterberg Limits Graph

FAT CLAY (CH), dark brown, very stiff

LEAN CLAY (CL), light brown, stiff to very stiff

- trace gravel between 6 and 8 feet

Boring Terminated at 10 Feet

Boring Log No. B-1

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

15.7

24.7

11.0

19.9

14.5

54-16-38

46-16-30

4.0

10.0

5-7-10 N=17

5-11-11 N=22

9-9-11 N=20

7-8-6 N=14

5-6-6 N=12

Advancement Method Flight Auger

Notes

Water Level Observations Groundwater not encountered

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

SCUCISD Clemens HS Parking Lot Addition

Hammer Type Automatic

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512 San Antonio, TX

6000 Northwest Pkwy Ste 100

Drill Rig

CME 55

Driller Burge

Logged by

BC

Boring Started 07-06-2026

Boring Completed 07-06-2026

Abandonment Method Boring backfilled with Auger Cuttings and/or Bentonite

S am pl e

T yp e

Pe rc en t

Fi n es

W at er C o n te n t

) Atterberg

Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.5633° Longitude: -98.2685°

Depth (Ft.)

Fi el d T es t

R es u lt s

FAT CLAY (CH), dark brown, stiff to very stiff

LEAN CLAY (CL), light brown, very stiff to hard

Boring Terminated at 10 Feet

Boring Log No. B-2

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

84.5

11.5

18.2

16.2

15.4

16.9

4-5-9 N=14

5-7-10 N=17

7-11-16 N=27

10-16-17 N=33

8-9-9 N=18

50-17-33

6.0

10.0

Advancement Method Flight Auger

Notes

Water Level Observations Groundwater not encountered

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

SCUCISD Clemens HS Parking Lot Addition

Hammer Type Automatic

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512 San Antonio, TX

6000 Northwest Pkwy Ste 100

Drill Rig

CME 55

Driller Burge

Logged by

BC

Boring Started 07-06-2026

Boring Completed 07-06-2026

Abandonment Method Boring backfilled with Auger Cuttings and/or Bentonite

S am pl e

T yp e

Pe rc en t

Fi n es

W at er C o n te n t

) Atterberg

Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.5628° Longitude: -98.2681°

Depth (Ft.)

Fi el d T es t

R es u lt s

FAT CLAY (CH), dark brown, stiff

CLAYEY SAND (SC), light brown, medium dense

Boring Terminated at 10 Feet

Boring Log No. B-3

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

39.3

14.4

9.7

8.8

5.7

6.1

37-14-23

20-15-5

2.0

10.0

3-5-7 N=12

5-7-7 N=14

8-7-7 N=14

7-9-9 N=18

8-8-9 N=17

Advancement Method Flight Auger

Notes

Water Level Observations Groundwater not encountered

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

SCUCISD Clemens HS Parking Lot Addition

Hammer Type Automatic

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512 San Antonio, TX

6000 Northwest Pkwy Ste 100

Drill Rig

CME 55

Driller Burge

Logged by

BC

Boring Started 07-06-2026

Boring Completed 07-06-2026

Abandonment Method Boring backfilled with Auger Cuttings and/or Bentonite

S am pl e

T yp e

Pe rc en t

Fi n es

W at er C o n te n t

) Atterberg

Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.5624° Longitude: -98.2678°

Depth (Ft.)

Fi el d T es t

R es u lt s

LEAN CLAY (CL), brown, stiff to very stiff

CLAYEY SAND (SC), light brown, medium dense to dense

Boring Terminated at 10 Feet

Boring Log No. B-4

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

13.4

14.3

12.8

5.2

4.3

44-17-27

26-12-14

6.0

10.0

3-6-7 N=13

8-10-14 N=24

5-9-13 N=22

25-17-13 N=30

10-12-16 N=28

Advancement Method Flight Auger

Notes

Water Level Observations Groundwater not encountered

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

SCUCISD Clemens HS Parking Lot Addition

Hammer Type Automatic

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512 San Antonio, TX

6000 Northwest Pkwy Ste 100

Drill Rig

CME 55

Driller Burge

Logged by

BC

Boring Started 07-06-2026

Boring Completed 07-06-2026

Abandonment Method Boring backfilled with Auger Cuttings and/or Bentonite

S am pl e

T yp e

Pe rc en t

Fi n es

W at er C o n te n t

) Atterberg

Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.5618° Longitude: -98.2675°

Depth (Ft.)

Fi el d T es t

R es u lt s

0 10 20 30 40 50 60 70 80 90 100 110

"A " L ine

ASTM D4318

CH

o r

OH

CL

or

OL

ML or OL

MH or OH

39.3 SC-SM

39.3 SC-SM

SILTY, CLAYEY SAND

Atterberg Limit Results

"U " L in e

Liquid Limit

LL PL PI Fines USCS DescriptionFines

Pl a st ic it y

In d ex

CL - ML

Facilities | Environmental | Geotechnical | Materials

2.5 - 4

6.5 - 8

4.5 - 6

2.5 - 4

6.5 - 8

2.5 - 4

6.5 - 8

B-1

B-1

B-2

B-3

B-3

B-4

B-4

Boring ID Depth (Ft)

6000 Northwest Pkwy Ste 100

San Antonio, TXTerracon Project No. 1000028512

1001 Elbel Road | Schertz, TX

SCUCISD Clemens HS Parking Lot Addition

Supporting Information

General Notes

Unified Soil Classification System

Split Spoon

> 4.00

2.00 to 4.00

1.00 to 2.00

0.50 to 1.00

0.25 to 0.50 less than 0.25

Unconfined Compressive Strength Qu (tsf)

SCUCISD Clemens HS Parking Lot Addition

1001 Elbel Road | Schertz, TX

Terracon Project No. 1000028512 6000 Northwest Pkwy Ste 100

San Antonio, TX

N

(HP)

(T)

(DCP)

UC

(PID)

(OVA)

Standard Penetration Test Resistance (Blows/Ft.)

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Unconfined Compressive Strength

Photo-Ionization Detector

Organic Vapor Analyzer

Water Level After a Specified Period of Time

Water Level After a Specified Period of Time

Cave In Encountered

Water Level Field Tests

Water Initially Encountered

Sampling

Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated.

Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations.

General Notes

Location And Elevation Notes

Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and Longitude are approximate. See Exploration and Testing Procedures in the report for the methods used to locate the exploration points for this project. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area.

Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data exist to classify the soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used. ASTM D2488 "Description and Identification of

Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly where insufficient laboratory data exist to classify the soils in accordance with ASTM D2487. In addition to USCS classification, coarse grained soils are classified on the basis of their in-place relative density, and fine-grained soils are classified on the basis of their consistency. See "Strength Terms" table below for details. The ASTM standards noted above are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment.

Exploration/field results and/or laboratory test data contained within this document are intended for application to the project as described in this document. Use of such exploration/field results and/or laboratory test data should not be used independently of this document.

Relevance of Exploration and Laboratory Test Results

Descriptive Soil Classification

> 30

2 - 4

Hard

> 50 Very Stiff

Stiff

Medium Stiff

Soft

Very Soft

30 - 50

10 - 29

4 - 9

0 - 3Very Loose

Loose

Medium Dense

Dense

Very Dense

Relative Density of Coarse-Grained Soils

(More than 50% retained on No. 200 sieve.)

Density determined by Standard Penetration Resistance

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

0 - 1

9 - 15

16 - 30

Relative Density Consistency Standard Penetration or

N-Value (Blows/Ft.)

Standard Penetration or N-Value

(Blows/Ft.)

Strength Terms

5 - 8

Unified Soil Classification System

Criteria for Assigning Group Symbols and Group Names Using

Laboratory Tests A

Soil Classification

Group Symbol Group Name

B

Coarse-Grained Soils:

More than 50% retained on No. 200 sieve

Gravels:

More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels:

Less than 5% fines C

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

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

Gravels with Fines:

More than 12% fines C

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

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

Sands:

50% or more of coarse fraction passes No. 4 sieve

Clean Sands:

Less than 5% fines D

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

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

Sands with Fines:

More than 12% fines D

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

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

Fine-Grained Soils:

50% or more passes the

No. 200 sieve

Silts and Clays:

Liquid limit less than

Inorganic:

PI > 7 and plots above “A” line J CL Lean clay K, L, M

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

Organic:

𝐿𝐿 𝑜𝑣𝑒𝑛 𝑑𝑟𝑖𝑒𝑑

𝐿𝐿 𝑛𝑜𝑡 𝑑𝑟𝑖𝑒𝑑

< 0.75 OL

Organic clay K, L, M, N

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:

𝐿𝐿 𝑜𝑣𝑒𝑛 𝑑𝑟𝑖𝑒𝑑

𝐿𝐿 𝑛𝑜𝑡 𝑑𝑟𝑖𝑒𝑑

< 0.75 OH

Organic clay K, L, M, P

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-inch (75-mm) sieve.

B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

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

E Cu = D60/D10 Cc =

F If soil contains ≥ 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 ≥ 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 ≥ 30% plus No. 200 predominantly sand, add

“sandy” to group name.

M If soil contains ≥ 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.

N PI ≥ 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.

DxD

)(D