Chap 5.pdf

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This PDF is available at http://nap.nationalacademies.org/25262
Guidelines for Managing Geotechnical
Risks in Design Build Projects (2018)
80 pages | 8.5 x 11 | PAPERBACK
ISBN 978-0-309-39060-6 | DOI 10.17226/25262
Douglas D. Gransberg, Michael Loulakis, Ali Touran, Ghada Gad, Kevin McLain,
Shannon Sweitzer, Dominique Pittenger, Ivan Castro Nova, Ricardo Tapia Pereira,
and Milagros Pinto-Nunez; National Cooperative Highway Research Program;
Transportation Research Board; National Academies of Sciences, Engineering, and
Medicine
National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for
Managing Geotechnical Risks in Design Build Projects. Washington, DC: The
National Academies Press. https://doi.org/10.17226/25262.

Guidelines for Managing Geotechnical Risks in Design–Build Projects
Copyright National Academy of Sciences. All rights reserved.
35
There is a need to align differences in perception of the geotechnical risk between owner and
contractor to avoid overestimating or underestimating the risks by either party and reduce con
flicts by effectively sharing the risk. This chapter will report the effective practices (tools) within
the context of available strategies and methods for managing geotechnical risk for DB projects.
5.1
Geotechnical Issues and Available
Risk Mitigation Strategies
The major factors for which a risk mitigation strategy is needed to resolve common geo
technical issues present in most DB projects are as follows. The list is not comprehensive but
general enough to apply to most, if not all, DB project delivery environments.
• Delays due to untimely actions by third party stakeholders.
• Inefficiencies in the project delivery process due to failure to include salient geotechnical risk
issues in the procurement process.
• Lost opportunities to avoid difficult geotechnical conditions.
• Claims due to DSC.
• Delays due to utility coordination, existence, and location failures.
• Poor quality post-award geotechnical investigations.
The corresponding list of respective strategies to align differences in perception of the geo
technical risk between owner and contractor and address the causes of geotechnical-related
issues on DB projects is as follows:
1. Implement early contractor design involvement through encouraging geotechnical ATCs
during procurement.
2. Use DB process to address other subsurface issues like utility company timeliness by involving
third party stakeholders as early as practical in project development and delivery.
3. Raise the visibility of geotechnical issues in DB projects to ensure competing contractor teams
understand the level of criticality on each project.
4. Avoid DSC claims through enhanced contract mechanisms designed specifically for address
ing geotechnical risks.
5. Promote an atmosphere of life cycle–based design and construction decision making with
respect to geotechnical risk on DB projects.
5.2 Methods for Implementing Tools
A method is a “regular, systematic way of accomplishing something.” Thus, in the geotechni
cal risk context, the method corresponds to the specific stage of project delivery in which the
project is being considered. Each stage has regular, systematic procedures that constrain the
C H A P T E R 5
Geotechnical Risk Management
Strategies, Methods, and Tools

36 Guidelines for Managing Geotechnical Risks in Design–Build Projects
ability of the project team’s use of the tools. Therefore, the appropriate methods for implement
ing the tools are defined as follows:
• Pre-advertising geotechnical risk management. This method consists of the typical activities
undertaken during preliminary engineering to identify and quantify geotechnical risks for
inclusion in a DB RFP.
• Procurement geotechnical risk management. This method consists of activities undertaken to
refine the DB project’s geotechnical risk profile during competitive DB proposal preparation.
• Pre-construction geotechnical risk management. This method consists of activities undertaken
after the award of the DB contract during the design phase of the project.
• Construction geotechnical risk management. This method consists of activities undertaken after
the award of the DB contract during the construction phase of the project.
5.3 Tools
A set of tools is identified as effective practices implemented by DOTs across the nation. An
effective practice is defined as “a practice found in the literature and validated as effective by
agencies.” Considering that there is no unified approach toward managing the geotechnical risk
in DB projects, this compilation of tools is made available for DOTs to implement and improve
practices as necessary.
Three of these tools (progressive DB, scope validation period, and multiple construction
notices to proceed) are identified as potential solutions for achieving an aligned approach
toward managing the geotechnical risks in DB projects. These tools are designed to get the
construction contractor into the field as early as practical to uncover the subsurface condi
tions and determine if there are indeed conditions that differ materially from those that would
reasonably have been expected during price proposal preparation. The use of one of these
tools shifts the geotechnical engineering from being design-centric to construction-centric
and recognizes that even the most extensive geotechnical investigations can still miss DSCs.
Therefore, the object of the post-award effort in this area is to expose those risks as quickly
as practical at a point early enough in project execution that the cost impact of the remedies
is minimized and any schedule impacts occur at a point where the maximum project float is
available to mitigate any delays.
This section identifies and describes the tools that can be implemented to manage geotechni
cal risks in DB projects. Table 5.1 lists the tools.
This section provides a brief description of each tool. More information is in Appendix C.
1. Flexible footprint for NEPA clearance. This tool depends on the agency selecting DB project
delivery early enough to influence the final form of the NEPA clearance. In essence, this tool
seeks to provide as much flexibility in the final permit as practical to avoid the potential that
attractive geotechnical design solutions are not unintentionally disallowed by commitments
made to obtain the permit in a timely manner.
2. Furnish geotechnical baseline report. Developed by the owner, who collects all the relevant
data from similar previous projects and the test results for the current project and assembles
the information into what will serve as the geotechnical baseline for bidders for decreasing
geotechnical uncertainty during procurement, which can make proposals received more
competitive.
3. Geotechnical conditions database. The advancement of computing power and the reduction
in data storage costs have made it feasible for agencies to create corridor-level geotechni
cal databases consisting of all the data gathered in past projects. The database can then be
mined to furnish information on site conditions for upcoming projects.

Geotechnical Risk Management Strategies, Methods, and Tools 37
4. Site conditions history from property owners during right-of-way acquisition.Property owners
will often have knowledge of a given parcel’s history and may be able to provide information
with regard to previous utilities and structures. Additionally, they may also have knowledge
of the presence of buried material such as demolition materials from previous structures,
as well as provide potential warning that contaminated material may be present. The tool
merely adds these questions to the right-of-way or ROW acquisition process and may trigger
the need to conduct sampling during preliminary engineering.
5. Prescriptive geotechnical design. DB project delivery is by definition performance-based in that
the contract is awarded before the design is complete. However, since geotechnical issues are
oftenonthecriticalpath,thistoolinvolvestheagencyprescribingageotechnicaldesignapproach
with which it is comfortable and stating in the DB RFP that no deviations will be permitted.The
result saves time during initial design reviews of subsurface features of work, which potentially
allows those design packages to be released for construction as early as practical if desired.
6. Performancespecificationsforpost-constructionperformance(subsidence,etc.).Tomitigatepoten
tial geotechnical-related failures in the operation phase of the project,an owner might include
a requirement for specific geotechnical-related performance warranties by the contractor.
7. Include differing site conditions clause. Much of the geotechnical claim generally falls under
changes due to DSC. The typical DSC clause provides broad relief to a contractor for site
conditions that differ materially from what is expected according to the contract documents.
The FHWA does not have a DSC mandate for DB projects. Nevertheless, many state DOTs
use a DSC clause in their DB contracts.
# Tool
1 Flexible footprint for National Environmental Policy Act of 1969 (NEPA)
clearance
2 Develop and furnish GBR in RFP
3 Geotechnical conditions database
4 Site conditions history from property owners during right-of-way acquisition
5 Prescriptive geotechnical design
6 Performance specifications for post-construction performance (subsidence, etc.)
7 Include DSC clause
8 Progressive DB
9 Request of geotechnical and/or utilities ATCs
10 Define no-go zones for geotechnical ATCs
11 Competitor designated boring locations
12 Competitors permitted to conduct supplementary borings at own expense.
13 Unit prices for contaminated material, over-excavation, etc.
14 Weight geotechnical evaluation criteria
15 Include life cycle criteria in best value award scheme
16 Scope validation period
17
Multiple NTPs with one designated for geotechnical investigation, design, and a second
specifically to commence excavations, utility work, etc.
18 Contractor produced GBR-C
19 Negotiated GBR interpretation
20 Differing site conditions allowance
21 Contaminated material allowance
22 Unforeseen utilities allowance
23 Assign design–builder responsibility for utility coordination
24 Validate proposed life cycle elements during design
25 Encourage life cycle related value engineering proposals from subcontractors
Table 5.1. List of tools for managing and mitigating
geotechnical risks.

8. Progressivedesign–build.Progressivedesign–build’sattractiontothegeotechnicalriskmanage
ment realm is the ability to negotiate the geotechnical risk after award and after the geotech
nical investigation has been completed rather than depending on the DSC clause to allocate
the subsurface risk. With progressive design–build, the first design and construction pack
age released for construction could begin the subsurface investigation and conduct selected
excavation on the project site to identify where the geotechnical issues will be encountered
and their magnitude. Thus, a fair and equitable amount for the realized subsurface risk can
be established. This eliminates the need for adding unnecessary contingencies in the price
because the uncertainty of the subsurface conditions is eliminated early in the project.
9. Request of geotechnical/utility-related alternative technical concepts (ATCs). ATCs allow pro
posers to submit alternative solutions to potential subsurface problems before the contract
is awarded; request ATCs (which the agency will hold confidential and preapprove if appli
cable) to identify geotechnical issues and enhance innovation in geotechnical design and
subsurface construction means and methods.
10. Define no-go zones for geotechnical ATCs.ATC no-go zones are those areas of the geotechnical
baseline design that may not be proposed for change during the DB procurement.
11. Competitor designated boring locations. Reduce geotechnical risk by conducting subsurface
explorations (borings) at strategic locations to provide reasonable geotechnical parameters
to the bidders. Additional borings are made available to all competitors but sometimes the
agency performs more borings to avoid giving away the location requested by a proposer so
the competitive advantage is retained. An important element for the success of the project
during the procurement phase is to have sufficient geotechnical information that allows
competitors to price the project without excessive contingencies.
12. Competitors permitted to conduct supplementary borings at own expense. Allow competing
design–builders to conduct their own pre-bid geotechnical investigations before devel
oping their proposals to reduce geotechnical uncertainty; an important element for the
success of the project during the procurement phase is to have sufficient geotechnical
information that allows competitors to price the project without excessive contingencies.
13. Unit prices for contaminated material, over-excavation, etc. A formalized geotechnical risk
allocation technique to draft the contract provision that uses selective unit pricing, which
provides an effective means for managing geotechnical quantity uncertainty.
14. Weight geotechnical evaluation criteria. Tailor relative geotechnical weight for the contractor
selection process in each DB project.
15. Include life cycle criteria in best value award scheme. Because design is where the quality
standards for construction are established,it is important that agency expectations for post-
construction life cycle performance be articulated in the solicitation and used to identify
successful approaches for managing geotechnical risks across the DB project’s life cycle. It
is also important to discuss those practices that did not adequately address the geotechnical
requirements and caused the agency to hold geotechnical liabilities that it had hope to shed.
16. Scope validation period. A period incorporated into the contract to allow the contractor
to discover any site conditions that differ from owner-furnished information early in the
project. After the end of the scope validation period, the design–builder’s claim rights are
waived for items not previously raised. This approach allows for an early resolution of
geotechnical-related issues and establishes a limit for the owner’s liability by assigning a
specific timeframe for DSC claims.
17. Multiple notices to proceed. Using multiple NTPs allows the owner to reduce the risk of DSC
by issuing an NTP only for the contractor’s subsurface exploration and underground work
before releasing the entire scope of work. This way there is a prioritization in removing the
uncertainty of the subsurface conditions early in the project so any differing site condition
is addressed before advancing to the next stages of the project.
18. Contractor produced geotechnical baseline report for construction (GBR-C). Developed for
baselining geotechnical conditions for a project to allocate geotechnical risk encountered

during construction; the owner collects all the relevant data from similar previous projects
and the test results for the current project (geotechnical data report).On the basis of the data
collected and test results the owner prepares a GBR for Bidding (GBR-B). The bidder uses
the GBR-B and augments it with its approach and design to develop a new version: the GBR
for Construction (GBR-C). It will incorporate the contractors’interpretation and approach
and the proposed means and methods. The owner should review the GBR-Cs prepared
by bidders and seek clarification on any issues as needed. On the basis of this review, the
owner will have the opportunity to seek adjustment of contract price if appropriate. After
the bidder has been selected, the bidder’s GBR-C will be incorporated into the DB contract
documents and forms the basis for risk allocation during the design–construction phase.
19. Negotiated GBR interpretation. This tool generally involves the use of a GBR-C as described
above and a GBR-B (the owner’s GBR used during bidding).After award of the DB contract
and the subsequent completion of the GBR-C, the owner and the design–builder compare
the two GBRs and agree on how to interpret a final GBR (GBR-F) during construction with
respect to the contract’s DSC clause. The aim is to mutually agree on what constitutes a
“material difference” and in doing so share the DSC risk on a project specific basis.
20. Differing site conditions allowance. Including a specified dollar amount (allowance) in the
RFP agreement for DSC to mitigate this commonly misallocated geotechnical risk.
21. Contaminated material allowance. Including a specified dollar amount (allowance) in the
RFP agreement for testing and handling of hazardous materials to mitigate this commonly
misallocated geotechnical risk.
22. Unforeseen utilities allowance. Including a specified dollar amount (allowance) in the RFP
agreement for addressing utilities discovered during construction to mitigate this commonly
misallocated geotechnical risk.
23. Assign design–builder responsibility for utility coordination. Transfer of utility coordination
activities from in-house personnel to contractor to enhance collaboration and early contrac
tor involvement.
24. Validate proposed life cycle elements during design. DB procurements often include both
design and evaluation criteria that seek to encourage life cycle design decision making by the
competing proposers.This tool consists of conducting the subsequent life cycle cost analysis
to validate that the winning proposal’s betterments indeed reduce the project’s projected life
cycle cost from that of the baseline design.
25. Encourage life cycle related value engineering proposals from subcontractors. Subcontractors
are technical specialists in their particular areas of expertise.This is particularly true in areas
like jet grouting, seismic retrofits, soil nails, and other geotechnical specialties.As such, they
are normally up to date with the state of technology and should be asked to review their
scopes of work for potential improvements that would reduce life cycle cost.
5.4 Strategies, Methods, and Tools for Risk Mitigation
The tools can be implemented by using the specific methods for executing the five risk mitiga
tion strategies, as presented in Tables 5.2 through 5.6.
In summary, aligning differences in perception of the geotechnical risk between owner and
contractor can potentially help an agency avoid geotechnical risk issues, such as unnecessary
contingencies and DSC claims. The goal is to mitigate the geotechnical risks by encouraging col
laboration between the parties in a DB contract. Implementing effective practices (tools) within
the context of available strategies and methods for managing geotechnical risk for DB projects
can facilitate the process.

Method Tool
Pre-advertising • Include GBR-C provision
• Provide a mechanism to conduct competing team requested additional borings,
i.e., permits, rights of access, etc.
• Collect potential contaminated material information during ROW acquisition
Procurement • Request geotechnical ATCs on DB projects
• Define no-go zones for geotechnical ATCs
• Competitor designated boring locations
• Competitors permitted to conduct supplementary borings at own expense
• Progressive DB
• Unit prices for contaminated material, over-excavation, etc.
Pre-construction • Scope validation period
• Multiple NTPs with one designated for geotechnical investigation, design, and a
second specifically to commence excavations, utility work, etc.
• Contractor produced GBR-C
• Negotiated GBR interpretation
Construction • Not applicable
Table 5.2. Risk Mitigation Strategy 1: Implement early contractor
design involvement.
Method Tool
Pre-advertising • Flexible footprint for NEPA clearance
• Utility conferences
• Site conditions history from property owners during ROW acquisition
Procurement • Request of utility-related ATCs
Pre-construction • Assign design–builder responsibility for utility coordination
Construction • Multiple NTPs with one designated for geotechnical investigation, design, and a
Table 5.3. Risk Mitigation Strategy 2: Involve third party stakeholders
as early as practical.
Method Tool
Pre-advertising • Geotechnical conditions database
• Furnish GBR
• Include GBR-C provision
• Provide a mechanism to conduct competing team requested additional borings,
i.e., permits, rights of access, etc.
• Flexible footprint for NEPA clearance
• Site conditions history from property owners during ROW acquisition
• Performance specifications for post-construction performance (subsidence, etc.)
Procurement • Include DSC clause
• Request of geotechnical ATCs
• Competitors permitted to conduct supplementary borings at own expense.
• Progressive DB
• Weight geotechnical evaluation criteria
Pre-construction • Assign design–builder responsibility for utility coordination
• Scope validation period
Construction • Requesting of utility-related ATCs
• Differing site conditions allowance
• Contaminated material allowance
• Unforeseen utilities allowance
Table 5.4. Risk Mitigation Strategy 3: Raise the visibility
of geotechnical issues.

Method Tool
• Furnish GBR
• Include GBR-C provision
• Prescriptive geotechnical design
Procurement • Request of geotechnical ATCs
• Competitors permitted to conduct supplementary borings at own expense.
Pre-construction • Assign design-builder responsibility for utility coordination
Construction • DSC allowance
• Contaminated material allowance
• Unforeseen utilities allowance
Table 5.5. Risk Mitigation Strategy 4: Enhanced DB geotechnical
contract mechanisms.
Method Tool
• Flexible footprint for NEPA clearance
• Site conditions history from property owners during ROW acquisition.
Procurement • Request of geotechnical ATCs
• Include life cycle criteria in best value award scheme
Pre-construction • Assign contractor responsibility for utility coordination
• Validate proposed life cycle elements during design
Construction • Encourage life cycle related value engineering proposals from subcontractors
Table 5.6. Risk Mitigation Strategy 5: Life cycle–based design and construction
decision making.

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