9-04 Geotechnical Report 10.1.2025.pdf

2000 South 15th Street, Waco, Texas 76706 Ph: 254-235-1048 LFEctx.com

October 1, 2025

BRW Architects 175 Century Square Drive, Suite 350 College Station, Texas 77840

Attention: Mr. Justin Hoermann, Associate AIA

Reference: Geotechnical Report Fire Station No. 2 Addition Temple, Texas LE Project No. W25-058

Dear Mr. Hoermann:

This letter transmits our geotechnical report, which has been electronically produced. We appreciate the opportunity to provide engineering services for you.

Once the project plans and specifications are completed, we would be pleased to review those portions that pertain to this report. We would also appreciate the opportunity to provide construction phase services such as materials testing as a part of the success of the project.

If you have any questions regarding our report, please call me at (254) 235-1048 or email JLangerman@LFEctx.com.

Best Regards, LANGERMAN ENGINEERING

Texas Registered Engineering Firm No. F-13144

James P. Langerman Engineering Intern

Distribution List:

• BRW Architects - Mr. Ray Holliday, AIA (RHolliday@BRWArch.com)

• BRW Architects – Mr. Justin Hoermann (JHoermann@BRWArch.com)

GEOTECHNICAL REPORT

Fire Station No. 2 Addition

Temple, Texas

LE Project No. W25-058

Report Prepared For:

BRW Architects Temple, Texas

October 1, 2025

Report Prepared By: Report Reviewed By:

James P. Langerman Engineering Intern

Scott M. Langerman, P.E.

Principal / Geotechnical Engineer

2000 South 15th Street, Waco, Texas 76706 Ph: 254/235-1048 LFEctx.com

Copyright 2025 Offices in Waco and Harker Heights, Texas Page 1 of 15 LE Project No. W25-058 Ph: 254-235-1048 LFEctx.com October 1, 2025

GEOTECHNICAL REPORT

FIRE STATION NO. ADDITION

TEMPLE, TEXAS

1.0 INTRODUCTION

Purpose: The purpose of this geotechnical report is to provide geotechnical design and construction criteria for a new Addition to Fire Station No. 2.

Geotechnical data and recommendations are provided in a brief, and hopefully user-friendly manner.

Authorization: Services were performed in general accordance with LE Proposal No.

GEO25-093, dated July 25, 2025. Authorization to proceed was provided by Mr. Ray Holliday, AIA on August 27, 2025. An amendment to excavate a test pit was authorized on September 8, 2025.

2.0 SUBSURFACE EXPLORATION

Drilling Date: September 11, 2025

Boring Layout: The boring location was staked in the field by Langerman Engineering personnel based on a site plan provided by Ms. Jamie Troester. Plates 1 and 2 show the approximate boring location.

If precise location and elevation data are desired, then a licensed professional land surveyor should be retained to locate the boring and determine the ground surface elevation.

Sampling Methods: Push tubes were used to sample the upper clay soils, and a split spoon sampler was used in hard clay soils and severely weathered limestone. The split spoon sampler was used in conjunction with standard penetration tests, and N-Values were recorded on the boring log. Marl was cored with an NX-size (2-inch) cutting bit. Water was used to cool the bit and discharge cuttings.

Test Pit: A test pit was excavated by hand on September 3, 2025.

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3.0 LABORATORY TESTS

Test Procedures: The following tests were conducted in general conformance with the standards noted in Table 3.1.

TABLE 3.1: LABORATORY TESTS

Test Name Test Method

Atterberg Limits ASTM D 4318

-#200 Mesh Sieve ASTM D 1140

Moisture Content ASTM D 2216

Soil Classification ASTM D 2487

Unconfined Compression (rock) ASTM D 7012

Unconfined Compression (soil) ASTM D 2166

Test Results: Laboratory test results are shown on Plate 3 in the Appendix, and selected test results on the boring log.

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4.0 SUBSURFACE MATERIALS AND SITE OBSERVATIONS

Stratigraphy: Major strata types for the boring are listed in Table 4.1., and a boring log is contained in the Appendix. Material descriptions are general and range of depths approximate because boundaries between different strata are seldom clear and abrupt in the field.

TABLE 4.1: MAJOR STRATA TYPES

Strata Depth to Top of

Strata (ft) Depth to Base of

Strata (ft) General Description

I 0 24 FAT CLAY and LEAN CLAY; brown, tan, and light gray, with calcareous nodules and iron oxide stains

II 24 30 MARL; tan

Strata changes are approximate, and in-situ transitions are usually gradual.

Geology: Based on the available geologic map1 of the area, and the contents of the borings, the site is located within the Taylor Formation.

The Taylor Formation consists of montmorillonitic clays that were deposited in a shallow marine environment. After deposition, the clays consolidated to form a weak rock-like shale and marl material when sufficient amounts of calcium carbonate were present as a cementing agent. This soft rock-like material is usually gray to dark gray in the unweathered state. Subsequent weathering produced highly expansive clay soils that were present in the boring.

Groundwater: Boring B-1 was drilled to a depth of 25 feet prior to using water to core marl. Marl was cored with water to cool the cutting bit and discharge cuttings. Groundwater was not observed above that depth. However, once water is added in the drilling process, further groundwater level readings are unreliable.

Transient groundwater is common in the area, and may be present during construction. The water tends to percolate down through the surficial soils until encountering a relatively impervious layer, and then either flow down gradient or become trapped. Water also flows through fractures in weathered limestone.

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The water observations conducted for this investigation are short-term and should not be interpreted as a groundwater study. However, the presence of groundwater may affect construction and long-term performance of the proposed foundations. If persistent groundwater is encountered during construction, then drain systems may be needed.

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5.0 GEOTECHNICAL FOUNDATION RECOMMENDATIONS

Project Summary: The project consists of a small addition to the fire station. It will have a foundation area of approximately 460 square feet.

Geotechnical recommendations for the new addition are included in

Sections 5 and 6 of this report.

Structural Loads: Details concerning structural design loads were not available for the preparation of this report. We assume that column loads will be similar to other one-story structures, perhaps on the order of 50 to 100 kips. If actual loads will be higher, then we should be contacted to re-evaluate our recommendations.

Expansive Soil: Clay soils in the Central Texas area are subject to expansive soil movements, which include swelling under moist conditions and shrinking under dry conditions. Moisture fluctuations occur due to seasonal wet and dry cycles, but are also influenced after construction by site grading, drainage, landscaping, and groundwater. Actual soil movement is difficult to determine due to the many unpredictable variables involved.

TxDOT uses the Potential Vertical Rise (PVR) procedure to estimate soil movements. For purposes of this project, the results of the laboratory tests, engineering judgment, and experience have also been considered.

The approximate PVR for a typical ground supported slab will be 2½ inches, which is considered moderately high for the Central Texas area.

Actual soil movements will depend on the subsurface moisture fluctuations over the life of the structure. Soil movements may be less than those calculated if moisture variations are minimized after construction. However, significantly larger soil movements than estimated could occur due to inadequate site grading, poor drainage, ponding of rainfall, and/or leaking utilities.

Test Pit: A test pit was excavated to determine the height of the grade beam and whether drilled shafts were used. Photographs of the test pit are included on Plate 2B in the Appendix. An 18-inch diameter drilled shaft was observed under the grade beam. A concrete “mushroom” was present at the top of the pier, likely due to wallowing of the pier hole during construction.

The slab is approximately 5.5 inches thick and appears to have been poured separately from the grade beams. The grade beams extend 12

Copyright 2025 Offices in Waco and Harker Heights, Texas Page 6 of 15 inches below the bottom of the slab.

Foundation Type: Based on the types of soils encountered in the boring, as well as the existing foundation type, we recommend using a slab on grade in conjunction with drilled piers for the addition.

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DRILLED PIERS WITH A SLAB ON GRADE

Figure 5.1: Sketch of Drilled Piers with a Slab on Grade (not to scale)

Risk: A properly designed and constructed foundation system consisting of drilled piers with a slab on grade, in conjunction with select fill, will offer a low risk of future foundation movements.

Elements outside of the building such as flatwork, drainage features, plazas, and utilities will experience adverse movements as a result of shrinking and swelling of the expansive clay soils, which may result in cracking and differential movements.

Straight-shaft Piers: Straight-shaft piers founded in Tan MARL, which was encountered at a depth of 24 feet, may be sized for an allowable end-bearing capacity of 30,000 pounds per square foot with a penetration of at least 4 feet into the bearing stratum.

An allowable side friction capacity of 2,500 psf (either tensile or compressive) may be used in Tan MARL after an initial penetration of 2 feet.

The piers should be specified to terminate on a hard layer, and not a softer clay layer, after the required penetration is achieved.

Transient Loads: The allowable end-bearing and side friction values may be increased by

30% for transient loads. However, that increase may not be combined with reduced ASD load combinations.

Uplift: Uplift forces will act on the piers as the clay soils surrounding the pier shaft swell. The following equation can be used to estimate the uplift force: UP= 40(d), where d is the pier diameter in feet, and UP is expressed in kips.

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Steel in the piers must be designed to resist uplift forces, and at least ½ percent steel should be used in the piers.

Pier Spacing: The side friction for piers spaced horizontally less than 3 diameters (center to center) should be multiplied by a reduction factor of 50%. Piers with horizontal spacing of 3 diameters or more are not subject to a side friction capacity reduction factor.

Settlement: Properly designed and constructed drilled shafts are expected to have a settlement of ½ inch or less.

Casing: Groundwater was not encountered during our field exploration, but may be present at the time of construction. Temporary steel casing may be necessary to seal out groundwater and prevent caving of the piers. We recommend that the contractor verify the drilling and groundwater conditions prior to commencing drilled shaft installation. Any adjustments to the pier depths must be made by LE.

Interior Slab: The slab must be supported in a uniform manner. At least 6 feet of the existing subgrade must be removed and then replaced with imported Select Fill below the building slab. The resultant PVR will be 1 inch or less.

Select fill must extend a horizontal distance of at least 2 feet beyond the perimeter of the new addition. Specifications for select fill are provided in Section 6. Carton forms below the grade beams are not necessary.

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MISCELLANEOUS DESIGN ITEMS:

Flatwork: This site is on highly expansive clay soils. Be aware that concrete flatwork such as sidewalks, drainage features, plazas, and utilities will be subject to adverse soil movements. The owner should be prepared to repair and even replace these items over time, depending on the magnitude of movement that actually occurs. Where the ground is intentionally sloped and graded to provide positive drainage, the ground may swell and shrink (or settle) sufficiently over time to reverse the intended drainage, and must be remediated when necessary.

The magnitude of shrink/swell movements can be reduced by placing select fill below items such as sidewalks and approaches to entrances.

From a practical standpoint, about 1-ft of select fill will help reduce the effects of the expansive clay soils. Cracks in ground-supported flatwork should be anticipated.

Connection to the Existing Structure: The new Addition will connect to the existing building. Care must be exercised in all excavations to avoid undermining the existing foundations.

Sheeting or shoring of excavations may be needed and must be evaluated by an engineer specializing in excavation stability.

The Addition should be structurally isolated, to the extent practical, from the existing structure to avoid cracking at the interface. We expect that differential movements will occur between the new/old foundations because the existing foundations have likely settled over time. The use of drilled piers for the new addition will help reduce future movements between the new/old. However, differential movements cannot be completely eliminated.

The contractor must include the proximity to adjacent features when planning their method of excavation and support. These features include, but are not limited to, adjacent structures and utility lines. The contractor must also be prepared to manage varying amounts of subsurface water.

Dewatering quantities will depend on drainage features, any groundwater, and rainfall prior to and during construction.

It is critical that excavations near the existing foundation do not cave and create voids. Figures 5.2 and 5.3 show two usual methods of excavating for select fill placement. When the wedge method is used, special care must be taken during rain events to avoid erosion of the wedge. It is desirable to place the select fill promptly after the excavation is complete.

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Figure 5.2: Create a 1:1 Wedge

Figure 5.3: Install Shoring (designed by competent professional)

Seismic: For structural designs based upon the 2018 IBC, the following criteria will apply. The Site Class is C. The Mapped Spectral Response Acceleration at short periods (SS) is about 0.08g, and the Mapped Spectral Response Acceleration at a 1 second period (S1) is about 0.04g. Site Coefficients are as follows: Fa= 1.3 and Fv= 1.5.

Hazards associated with slope stability, soil liquefaction, surface rupture, and lateral spreading are not considered an issue with this site due to the study area being in a seismically inactive area.

Vapor Barriers: The need for vapor barriers, and where to place them, must be determined by the architect or structural engineer based on the proposed floor treatment, building function, concrete properties, placement techniques, code requirements, and the construction schedule. When moisture barriers are used, precautions should be taken during the initial floor slab concrete curing period to reduce differential curing and possible curling of the slabs.

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Impervious Seal: We recommend that an impervious seal consisting of at least 12 inches of clay soil be constructed on top of the backfill material around the building perimeter. The intent of this impervious seal is to reduce surface runoff water from infiltrating the backfill. The seal must be sloped away from the foundation. In addition, a “plug” of clay soil must be placed at the exit points of the utilities from the foundation to reduce water intrusion into utility trenches.

Subgrade Improvement: Some of the onsite soils may be subject to pumping of the subgrade, and we should be contacted if this situation occurs. Clean crushed stone may be placed at the base of the excavations to create a firm working surface where needed and/or specified. We expect that a layer of about 6 to 8 inches in thickness will be needed if soft and/or wet subgrade conditions are present, but field conditions may dictate an increased thickness. If more than about 10 inches is needed, then a filter fabric may be needed to avoid migration of fines.

The crushed stone must be clean, and should generally range in size from

3 to 6 inches. Compaction specifications do not apply; however, the stone should be placed in such a manner that will stabilize the bottom of the excavations. This type of clean stone is normally used to stabilize construction entrances, and should be readily available. Be aware that plumbing and other features that require trenching will be difficult to install if the trenches extend into the clean stone.

Utility Connections: Utilities resting on or within expansive soils are subject to soil movements.

Utility connections should account for such movement potential, such as using flexible connections.

Based on our previous experience, clay soils are corrosive to buried metals.

Corrosion protection should be provided for such metals. If granular backfill materials are used for the utility lines, then a clay plug must be placed at the exterior foundation penetrations to avoid water intrusion and collection within the utility trenches.

Review by MEP: We recommend that this report be provided to the project Mechanical, Electrical, and Plumbing engineers (MEP’s). Their designs should account for the estimated soil movement potential. We are available to help with questions they may have about soil movements.

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6.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS

Site Preparation: Surficial vegetation, root systems, existing utilities, old foundations, and any underground structures must be removed below the building pad. The stripping depth must be based on field observations with attention given to old drainage areas, uneven topography, and wet soils. Proof-rolling should be used to detect soft spots or pumping subgrade areas. Proof-rolling should be performed using a heavy pneumatic tired roller, loaded dump truck, or similar piece of equipment weighing at least 25 tons.

Grading: Grading, landscaping, and drainage pose a significant risk factor for future performance of the foundation systems. Prevention of water ponding around the foundation is critical. We suggest the following general guidelines for perimeter drainage:

1. The building pad or the finished floor elevation must be elevated from the exterior finished grade to assist in draining the surface water away from the structure.

2. Where possible, extend paved surfaces up to the building line to serve as a barrier to soil moisture evaporation and infiltration. These surfaces must slope away from the building.

3. Outlets for gutter systems must rapidly discharge water away from the foundation.

4. Roots from trees and decorative vegetation remove moisture from soils, which causes soil shrinkage (settlement). Trees should have root blockers near the foundation or be located as far away from the foundation as practical.

5. Sprinkler systems must be properly maintained and over-watering of the soils should be avoided.

Subgrade: The subgrade soils should be compacted to at least 95 percent of ASTM D698 (or TEX-113-E) maximum dry density at 0 to +3% of the optimum moisture content. Proof-rolling may be used in lieu of compaction testing of the subgrade, but will require approval by LE on a case-by-case basis. In most cases, compaction testing will be required.

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Select Fill: Imported Select Fill should meet the requirements of 2014 TxDOT Item 247, Type A, Grade 3 or better. The select fill material should be compacted to at least 95 percent of ASTM D698 (or TEX-113-E) maximum dry density at 0 to +3% of the optimum moisture content. Crusher fines are not acceptable.

A maximum compacted lift thickness of six inches must be specified, with each lift tested for compliance prior to the addition of subsequent lifts.

The placement and compaction of fill material must be observed, monitored, and tested by LE on a full-time basis.

Foundation: Foundation and drilled shaft construction recommendations are listed below.

1. A minimum pier shaft diameter of 24 inches is normally specified to allow for cleaning, minimum construction tolerances, and conventional concrete mix designs. Smaller diameters may be used at the discretion of the structural engineer.

2. The foundation construction must be observed by LE to determine that the proper bearing material has been reached in accordance with the recommendations given herein.

3. Prior to the placement of concrete, water must be removed from the foundation excavations. Prolonged exposure or inundation of the bearing surface with water may result in changes in bearing strength and compressibility characteristics. If delays occur, drilled shaft excavations should be deepened and cleaned, in order to provide a fresh bearing surface.

4. Concrete must be placed promptly after the excavations are completed, cleaned, and observed. Drilled piers must be concreted before the end of the work day.

5. The reinforcement steel cage placed in the shaft must be designed from the standpoint of meeting at least two requirements: (1) the structural requirements for the imposed loads; and (2) stability requirements during the placement of concrete.

6. Groundwater was not encountered during our field exploration, but may be present during construction. Temporary steel casing may be required to seal out groundwater and/or prevent the pier

Copyright 2025 Offices in Waco and Harker Heights, Texas Page 14 of 15 holes from caving. Special concrete design and construction procedures as described in ACI 336.1 and ACI 336.3R should be specified in order to properly extract the casing during concrete placement. The pier concrete should be placed at a minimum slump of 6 inches when temporary steel casing is used. We advise that the bid schedule include installation of temporary casing as a separate unit-price bid item.

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7.0 DESIGN REVIEW AND LIMITATIONS

Design Review: The recommendations contained in this report were based on preliminary site plans and design information provided by the Client. Our recommendations may not be applicable if changes have been made to the original information that formed the basis for this report, and we must be retained to make a determination if changes have been made. We also must be given the opportunity to review construction documents to affirm that our recommendations have been interpreted correctly. We cannot be responsible for misinterpretations if not given the opportunity to review aspects of the project that are based on the contents of this report.

A review is considered an additional service.

Limitations: This report has been prepared for the exclusive use of our client and their designated project design team. Preparation of the report has been performed using that degree of care and skill ordinarily exercised under similar conditions by reputable geotechnical engineers practicing in the same locality. No warranties, express or implied, are intended or made.

As stated in the attachment “Important Information about Your Geotechnical Engineering Report”, the subsurface conditions are interpreted from samples taken only at the boring locations. During construction, variations will be encountered, and will require interpretation by LE to verify the adequacy of the geotechnical recommendations. Other concerns and limitations are discussed in the attachment.

This investigation did not include environmental testing or evaluations, and does not address whether landfilling operations, as defined by the State of Texas, have occurred on the property. An environmental professional should be retained to address environmental issues.

8.0 REFERENCES:

1. Geologic Atlas of Texas, Waco Sheet, Bureau of Economic Geology, The University of Texas at Austin, Austin, Texas 1970.

APPENDIX

Site Location Map Boring Location Sketch Laboratory Test Results Boring Logs Important Information about Your Geotechnical Engineering Report

SITE LOCATION MAP

FIRE STATION NO. 2 ADDITION

LE PROJECT NO. W25-058

PLATE

Fire Station No. 2

BORING LOCATION MAP

2A

B - 1

Test Pit

BORING LOCATION MAP

2B

B-1 0.0 - 2.0 18 106.8 6.9 6.0 B-1 2.0 - 4.0 48 17 31 95 17 B-1 4.0 - 6.0 15 115.4 5.7 2.4 B-1 6.0 - 8.0 43 17 26 85 15 B-1 10.0 - 12.0 56 19 37 93 18 B-1 18.5 - 20.0 94 15 B-1 25.1 - 93.9 2.0 B-1 26.7 - 84.3 1.5

Liquid Limit

Unconfined Compressive

Strength (tsf)

Plastic Limit

Plasticity Index

Project: Fire Station No. 2

Project Number: W25-058

Summary of Laboratory Results

Moisture Content

Percent Passing No. 200 Sieve

Sample Depth

(ft.)

Boring No.

Strain at Failure

Unit Dry Weight

(pcf)

Plate 3

6.0

2.4

2.0

1.5

6.9

5.7

93.9

84.3

(44)

4.5+

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4.5+

4.5+

4.5+

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ST

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A

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A

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RC

LEAN CLAY; brown, with calcareous nodules

--- iron oxide stains below 3 feet

LEAN CLAY; tan, with sand and iron oxide stains

--- light gray below 8 feet

FAT CLAY; light gray, with calcareous nodules and iron oxide stains

--- tan and light gray below 18.5 feet

MARL; tan

12-19-27 (46)

30-50/3"

ATTERBERG

LIMITS

Remarks:

Completion Depth:

Date Started:

Completed:

Logged by:

Boring was advanced to a depth of 25 feet before using water in the rock core drilling process. Groundwater was not observed above that depth.

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Geotechnical-Engineering Report Important Information about This

Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.

While you cannot eliminate all such risks, you can manage them. The following information is provided to help.

The Geoprofessional Business Association (GBA) has prepared this advisory to help you – assumedly a client representative – interpret and apply this geotechnical-engineering report as effectively as possible. In that way, you can benefit from a lowered exposure to problems associated with subsurface conditions at project sites and development of them that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed herein, contact your GBA-member geotechnical engineer.

Active engagement in GBA exposes geotechnical engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for everyone involved with a construction project.

Understand the Geotechnical-Engineering Services Provided for this Report Geotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities.

The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations.

Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions.

Geotechnical-Engineering Services are Performed for Specific Purposes, Persons, and Projects, and At Specific Times Geotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client.

Likewise, geotechnical-engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical-engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project.

Do not rely on this report if your geotechnical engineer prepared it:

the original site); or

• before important events occurred at the site or adjacent to it;

e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations.

Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time – if any is required at all – could prevent major problems.

Read this Report in Full Costly problems have occurred because those relying on a geotechnical-engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only. Read and refer to the report in full.

You Need to Inform Your Geotechnical Engineer About Change Your geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys.

Typical changes that could erode the reliability of this report include those that affect:

function or weight of the proposed structure and the desired performance criteria;

As a general rule, always inform your geotechnical engineer of project or site changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.

Most of the “Findings” Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site’s subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly, whenever needed.

This Report’s Recommendations Are Confirmation-Dependent The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation.

This Report Could Be Misinterpreted Other design professionals’ misinterpretation of geotechnical-engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team, to:

specifications; and

• be available whenever geotechnical-engineering guidance is needed.

You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction-phase observations.

Give Constructors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect.

Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes.

To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations,” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions.

Your geotechnical engineer should respond fully and frankly.

Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical-engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site, ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance.

Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer’s services were not designed, conducted, or intended to prevent migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies.

Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team.

Geotechnical engineers are not building-envelope or mold specialists.

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