ESBD_382095_1732287516695_RFB 2024-084 Wetlands Pump Station Project.pdf

Purchasing Services Post Office Box 2570

Waco, Texas 76702-2570 Phone: 254-750-8098

Fax: 254-750-8063 melaniew@wacotx.gov

CITY OF WACO www.waco-texas.com

Date: 11/22/2024

RFB No: 2024-084 Commodity: Wetlands Pump Station Project Purchasing Agent: Melanie Wade

Closing Time: 2:00 P.M. CST, Wednesday, December 4, 2024 Opening Time: 2:05 P.M. CST, Wednesday, December 4, 2024

RFB Opening Location: Via Zoom Video and Dial In

Addendum No: 1

Questions answered at pre-bid Map attached

Geotechnical report

The above-mentioned RFB has been changed. Sign and return addendum to the Purchasing Office by the closing time and date with your RFB response. Returning this page signed by your authorized agent will serve to acknowledge this change. All other requirements of the invitation remain unchanged. If you have any questions, please call or stop by the Purchasing Office at the above address.

Firm:____________________________________________________________________________________

Address___________________________________________________________________________________

Signature of Person Authorized to Sign Bid:______________________________________________________________________

Signor's Name and Title (print or type):_____________________________________________________________________________

E-mail Address:____________________________________________________________________________

Date:____________________Telephone:___________________________Fax:_________________________ mailto:melaniew@wacotx.gov file://NETAPP/HOMES/JodyC/0%20Purchasing/Utilities/2014/RFB%202014-012%20Generator%20Rebuild/www.waco-texas.com

Questions – RFB 2024-084 Wetland Pump Station Project

• Commissioning and start-up coordination, how is that going to unfold? With 3rd party? This will be inspected by the City of Waco, but can change to third party based on availability

• Locations for the Geotech bores See attached reports

• Who is the electric provider and who will be responsible to pull the primary? The electric provider is Heart of Texas Electric Cooperative (HOTEC) and they will be responsible for the service modifications, see bid tab for cost

• Who is doing control, is it designated to someone or up to the contractor. Where is the control narrative and schematic? The programming will be the responsibility of the contractor or designee, see plans in RFB

• Are the pumps functional currently? Not fully functional at the moment

• Is there a need to maintain operation and flow of the station during construction? Answered that continual operation is not necessary

2000 South 15th Street, Waco, Texas 76706 Ph: 254-235-1048 www.LFEctx.com Fx: 254-235-1625

July 8, 2022

City of Waco Public Works Department P.O. Box 2570 Waco, Texas 76702-2570

Attention: Mr. Charles Leist, P.E.

Reference: Geotechnical Report Wetlands Electric Platform Waco, Texas LFE Project No. W22-041

Dear Mr. Leist:

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.

Best Regards, LANGERMAN FOSTER ENGINEERING COMPANY

Texas Registered Engineering Firm No. F-13144

Scott M. Langerman, P.E.

Principal / Geotechnical Engineer

Distribution List:

City of Waco- Mr. Charles Leist, P.E. (CharlesL@WacoTx.gov) City of Waco- Ms. Linda Dvorak (LDvorak@WacoTx.gov) City of Waco- Mr. Chet Warren (ChetW@WacoTx.gov)

GEOTECHNICAL REPORT

Wetlands Electric Platform Waco, Texas

LFE Project No. W22-041

Report Prepared For:

City of Waco Waco, Texas

Report Prepared By:

Scott M. Langerman, P.E.

Principal / Geotechnical Engineer

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

July 8, 2022

Copyright 2022 2000 South 15th Street, Waco, Texas 76706 Page 1 of 9 LFE Project No. W22-041 Ph: 254-235-1048 www.LFEctx.com Fx: 254-235-1625 July 8, 2022

GEOTECHNICAL REPORT

WETLANDS ELECTRIC PLATFORM

WACO, TEXAS

1.0 INTRODUCTION

Purpose: The purpose of this report is to provide geotechnical design and construction criteria for a new Wetlands Electric Platform on Baylor Camp Road. Geotechnical data and recommendations are provided in a brief, and hopefully user friendly manner.

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

GEO22-084R1, dated June 1, 2022. Authorization to proceed was provided by Mr. Charles Leist, P.E. on June 3, 2022 using City of Waco Purchase Order No. 22200247.

2.0 SUBSURFACE EXPLORATION

Drilling Date: June 24, 2022.

Boring Layout: The boring was staked in the field by Walker Partners, and the location is shown on Plates 1 and 2 in the Appendix. Coordinates provided by Walker Partners are listed below.

Grid Northing: 10563984.62 Grid Easting: 3238489.77 Elevation: 466.00 feet

Sampling Methods: Push-tubes and a split-spoon were used to sample soil materials and weathered limestone to a depth of 30 feet. The split spoon sampler was used in conjunction with standard penetration tests, and N-Values were recorded on the boring log.

Limestone was cored with an NX-size (2-inch) cutting bit, and water was used to cool the bit and discharge cuttings. Coring was initiated at a depth of 30 feet in the boring.

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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 (soil) ASTM D 2166

Unconfined Compression (rock) ASTM D 7012

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

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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 28 SANDY LEAN CLAY, LEAN CLAY, and CLAYEY SAND/GRAVEL; brown, dark gray-brown, gray-brown, tan, and gray

II 28 30 WEATHERED LIMESTONE; tan, fractured

III 30 40 LIMESTONE; gray, fractured, with marly layers

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 boring, the site is located within Alluvial Deposits overlying the Washita Group.

Alluvial Deposits are derived from meandering paths and flood events of the Brazos River. Due to the inconsistent means of deposition, the deposits vary both horizontally and vertically in content and engineering properties. At this site, most of the soils consist of interbedded layers of clay, sand, and gravel. From a geologic perspective, terrace deposits are considered recent.

The Cretaceous Period Washita Group is comprised of the undivided Denton Clay, Fort Worth Limestone, Duck Creek Limestone, Kiamichi Clay, and Edwards Formation. We cannot precisely determine which of these sub-formations were present in the boring, and more than one may have been encountered.

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Groundwater: The boring was drilled to a depth of 30 feet prior to using water in the rock core drilling process. Water was used in the core drilling process to cool the core bit and to discharge cuttings. Groundwater was initially encountered at a depth of 12.5 feet. Drilling was then halted for a 10 minute observation period, and the water level rose to 10 feet.

Groundwater will be present during construction due to the proximity of the Brazos River. We generally expect the water level to be within a few feet of the Brazos River stage.

The water observations conducted for this investigation are short-term and should not be interpreted as a groundwater study. However, the presence of groundwater will affect construction and long-term performance of the proposed foundation.

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5.0 GEOTECHNICAL FOUNDATION RECOMMENDATIONS

Project Summary: The projects consists of an Electric Platform that will have dimensions of

20-ft by 20-ft. It will be elevated about 10 feet above the ground, and will be supported with columns extending to drilled piers.

Foundation Type: Straight-Shaft Drilled Piers. Due to the presence of groundwater at a depth of 10 feet, the piers will need to have temporary casing extending to Gray Limestone at a depth of about 30 feet. Above 30 feet, there are not any soils capable of effectively sealing off groundwater coming from the base of the piers.

Bearing Stratum: Gray LIMESTONE

End Bearing: Straight-shaft piers founded in Gray LIMESTONE may be sized for an allowable end-bearing capacity of 30,000 pounds per square foot with a penetration of at least 3 feet into the bearing stratum. The piers should be specified to terminate on a hard layer, and not a softer marly clay layer.

Side Friction: An allowable side friction capacity of 500 psf (either tensile or compressive) may be used starting at a depth of 10 feet below the ground surface. The side friction may be increased to 2,500 psf in Gray

LIMESTONE.

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. End-bearing is not affected by pier spacing provided that the bases are at roughly the same elevation.

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 from clay soils on drilled piers are expected to be minor.

However, we recommend that at least ½ percent steel be used in the piers.

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Lateral Loads: The drilled piers will be subject to lateral forces, and must be designed to limit deflection at the ground surface. Table 5.1 contains geotechnical design parameters for use with L-Pile Version 2018 software.

TABLE 5.1: LATERAL LOAD DESIGN PARAMETERS (L-PILE 2018)

Depth (feet)

Soil Type L-Pile Soil

Type Cohesion

(psf) φ

(deg) Ks (pci)

Unit Wt (2) (pcf) e50 (Soil) or Krm (Rock)

Initial Modulus of Rock Mass (psi)

Uniaxial Comp.

Strength (psi)

0 - 4 Clay Stiff Clay w/out Free Water

200 -- -- 115 0.020 --- ---

4 – 6 Clay Stiff Clay w/out Free Water

500 -- -- 120 0.015 -- --

6 – 8 Clayey

Sand/Gravel Sand -- 30 20 120 -- -- --

8 – 18.5 Clay Stiff Clay w/out Free Water

500 -- -- 120 0.015 -- --

18.5 – 23 Clayey

Sand/Gravel Sand -- 31 50 120 -- -- --

23 – 27 Clay Stiff Clay w/out Free Water

1,500 -- -- 120 0.007 -- --

27 – 28 Clayey

Sand/Gravel Sand -- 36 100 120 -- -- --

28 – 40

Weathered Limestone and Limestone

Weak Rock -- -- -- 135 0.0005 10,000 700

(1) Minor cohesion, unit weight, and modulus as listed above may be used to account for the effect of the overburden soils in the top 4 feet.

(2) Unit weights listed above represent total unit weights. In conditions where soils are below the water table, submerged unit weights should be used. Submerged unit weight is obtained by subtracting the unit weight of water from the unit weight listed above. Unit weight of water is 62.4 pcf.

Copyright 2022 2000 South 15th Street, Waco, Texas 76706 Page 7 of 9 LFE Project No. W22-041 Ph: 254-235-1048 www.LFEctx.com Fx: 254-235-1625 July 8, 2022

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

Casing: Groundwater is expected due to the proximity of the Brazos River, and was logged at a depth of 10 to 12.5 feet in our boring. Temporary steel casing will be necessary to seal out groundwater and prevent caving of the piers. We believe that the casing will need to extend into gray limestone to provide a proper seal. We recommend that the contractor verify the drilling and groundwater conditions prior to commencing drilled shaft installation.

MISCELLANEOUS DESIGN ITEMS:

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.

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 LFE 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.

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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 is expected due to the proximity of the Brazos

River. Temporary steel casing will be required to seal out groundwater and/or prevent the pier 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.

Copyright 2022 2000 South 15th Street, Waco, Texas 76706 Page 9 of 9 LFE Project No. W22-041 Ph: 254-235-1048 www.LFEctx.com Fx: 254-235-1625 July 8, 2022

6.0 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. Such 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 LFE 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.

7.0 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

LFE PROJECT NO. W22-041

PLATE

Wetlands Electric Platform

BORING LOCATION SKETCH

LFE PROJECT NO. W22-041

PLATE

B - 1

Sketch provided by the City of Waco. Boring was staked by Walker Partners with the coordinates listed below.

N 10563984.62 (Grid) E 3238489.77 (Grid)

B-1 2.0 - 4.0 35 16 19 60 15 B-1 4.0 - 6.0 14 123.4 0.6 4.0 B-1 6.0 - 8.0 37 16 21 28 12 B-1 10.0 - 12.0 40 17 23 74 23 B-1 13.0 - 15.0 89 26 B-1 18.5 - 20.0 20 16 B-1 23.0 - 25.0 97 27 B-1 35.1 - 2.6 2.3 B-1 36.2 - 51.8 1.3 B-1 38.2 - 94.4 1.0

Liquid Limit

Unconfined Compressive

Strength (tsf)

Plastic Limit

Plasticity Index

Project: Wetlands Electric Platform

Project Number: W22-041

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

(0)

(52)

12-8-6 (14)

50/3"

50/2"

460.0

458.0

453.0

447.5

443.0

439.0

438.0

436.0

426.0

4.0

2.3

1.3

1.0

0.6

2.6

51.8

94.4

4.5+

4.5+

1.0

0.5

1.0

0.5

0.5

1.5

ST

ST

ST

ST

ST

ST

A

ST

A

SS

A

ST

A

SS

A

RC

T

RC

SANDY LEAN CLAY; brown, with gravel

CLAYEY SAND and GRAVEL; dark gray-brown

LEAN CLAY; gray-brown, with sand

LEAN CLAY; brown, trace sand

CLAYEY SAND and GRAVEL; tan and gray

LEAN CLAY; dark gray-brown

CLAYEY SAND and GRAVEL; tan

WEATHERED LIMESTONE; tan, fractured

LIMESTONE; gray, fractured, with marly layers

--- less fractured below 36 feet

R E

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40 ft.

6/24/22

6/24/22

L. Fleischhauer

Remarks:

Completion Depth:

Date Started:

Completed:

Logged by:

Boring was advanced to a depth of 30 feet before using water in the rock core drilling process. Groundwater was observed at a depth of

12.5 feet. After a 10 minute observation period, groundwater was observed at a depth of 10 feet.

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MATERIAL DESCRIPTION

Approximate Surface Elevation 466 feet

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BORING NO. B-1

CLIENT City of Waco

PROJECT NUMBER W22-041

PROJECT NAME Wetlands Electric Platform

PROJECT LOCATION Waco, Tx

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J Langerman Foster Engineering Company Waco and Harker Heights (Killeen), Texas Ph: 254-235-1048 www.LFECTX.com

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:

• for a different client;

• for a different project or purpose;

• for a different site (that may or may not include all or a portion of 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:

• the site’s size or shape;

• the elevation, configuration, location, orientation, function or weight of the proposed structure and the desired performance criteria;

• the composition of the design team; or

• project ownership.

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:

• confer with other design-team members;

• help develop specifications;

• review pertinent elements of other design professionals’ plans and 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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