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Managing Geotechnical Risks in Design–Build Projects (2018)

Chapter: Appendix B: Case Study Reports

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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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Suggested Citation:"Appendix B: Case Study Reports." National Academies of Sciences, Engineering, and Medicine. 2018. Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25261.
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B-1 Appendix B: Case Study Reports As part of Task 3a of the research proposal, a case study protocol was developed based on the findings from the surveys, the content analysis and the literature review with the objective of identifying, analyzing and understanding the current models for successful geotechnical risk management on projects delivered using DB project delivery. This protocol is then used to conduct structured face-to-face interviews, producing results with established points of comparison and a high level of reliability. Interviews were performed on eleven (11) case study projects identified by the research team across nine (9) states: California, Indiana, Maryland, Missouri, North Carolina, Ohio, South Carolina, Texas and Utah. All of these case studies are projects that involved significant geotechnical risks and several differences and similarities were found in the way the DOTs managed them, which provided valuable insight towards identifying different strategies, tools and methods that are currently being used to handle the geotechnical risk. Table B.1 shows a listing of all the performed case studies. Table B.1 - List of Performed Case Studies (Task 3a) Case No. Agency Case Study Project Contract Award Year Contract Amount 1 Missouri DOT I-64 Daniel Boone Bridge over the Missouri River 2012 $111,000,000 2 Caltrans I-15/I-215 Interchange at Devore 2012 $208,000,000 3 Indiana DOT PR 69 from Taylor Ridge Road to 1435 west of CR 750E 2013 $110,000,000 4 Utah DOT I-15 Corridor Reconstruction Project 1997 $1,600,000,000 5 Utah DOT SR-73 Pioneer Crossing, Lehi 2009 $282,361,000 6 Texas DOT Dallas, Horseshoe Project 2012 $818,000,000 7 Maryland SHA IS-270 Innovative Congestion Management Project ~2017 $100,000,000 8 Ohio DOT Columbus Crossroad - Project 1 2011 $200,350,000 9 Ohio DOT Cleveland Innerbelt CCG1 (I90WB Bridge) 2010 $287,400,000 10 South Carolina DOT Port Access Road 2016 $220,700,475 11 North Carolina DOT I-40 Landslide Project 2004 $10,574,740

B-2 This appendix details the findings from each of the performed case study interviews and provides supporting information on the way the geotechnical risks were contractually handled by the different agencies. Table B. 2 shows a summary of the distinct characteristics representing how the risk was managed in terms of mitigation actions implemented pre-award. Table B. 2 - Summary of Case Studies - Geotechnical Risk Mitigation Actions Case No. State Case Study Mitigation Action 1 Missouri I-64 Daniel Boone Provide as much information as possible to proposers, accepting requests for additional investigation. 2 California I-15/I-215 Devore Perform additional studies if the project requires it. Prescriptive requirements. 3 Indiana PR 69 Perform as much geotechnical investigation as DBB. Mandatory soil improvement design. 4 Utah I-15 Reconstruction GDR nearly 100% AASHTO. Increase settlement warranty requirement. 5 SR-73 Pioneer Exclude owner's studies from DSC clause. Mandatory specifications and extended warranty for settlement. 6 Texas Dallas Horseshoe DSC clause with caps. Two NTPs. Not limiting contractor's geotechnical investigation. Mandatory pavement designs. 7 Maryland IS-270 Innovative C Progressive DB. Scope validation period. Appropriate amount of studies (not too much). 8 Ohio Columbus Crossroad First $250,000 of DSC is considered incidental. Requirement for contractor to provide GBR for tunneling. 9 Cleveland Innerbelt Robust subsurface exploration. Requirements for deep foundations and drilled shafts. A $500,000 DSC threshold was included. 10 South Carolina Port Access Road Extensive geotechnical and environmental investigation (including deep boring). Threshold for Hazmat. Seismic parameters provided. Elimination of geotechnical DSC. 11 North Carolina I-40 Landslide Provide as much raw data as possible in the contract. Allow requests for more borings. No DSC clause. Nested DB. Case Study 1: I-64 Daniel Boone Bridge over the Missouri River – St. Louis, Missouri This project was selected as a case study to illustrate the benefits of incorporating the proposers’ criteria in the geotechnical risk identification before awarding the contract and how the Missouri DOT (MoDOT) handles projects with high potential of geotechnical risks. Although MoDOT treats every major bridge as a project with significant geotechnical risks, in this case study the proposers identified the risk of liquefaction in one of the abutments during the two-phase letting process.

B-3 Location: St. Louis, Missouri Award Year: 2012 Contract Amount: $111,000,000 Status: Completed Scope of work: The project consists of building a new bridge over the Missouri River to connect St. Charles and St. Louis, replacing the existing 80-years old structure which is required to be removed, and constructing a bicycle pedestrian facility to connect the Katy Trail State Park to the Monarch Levee Trail. Geotechnical Risks: MoDOT considers that every bridge project has a higher geotechnical risk as compared to other projects. The risk analysis initially performed by MoDOT included the identification of Differing Site Conditions, Scour and Settlement as geotechnical risks related to this project. Table B. 3 shows MoDOT’s Risk Assessment Worksheet for this project where a quantitative analysis was performed for each identified risk. This case study stands out for analysis since a complex geotechnical risk such as the potential for liquefaction was identified by the proposers during the procurement process. Additionally -during construction- the design-builder found metallic underground debris (sheet piles) and boulders near the bridge piers, which impacted the foundation works. Table B. 3 - MoDOT Risk Assessment Worksheet – Geotechnical / Daniel Boone Bridge Project Risk Element Impact to Project Goals Low—Med— High 0 3 6 Effort to Mitigate Risk Low—Med— High 0 3 6 Probability of Impact (if no action taken) 0—1.00 Risk Factor A*B*C Differing Site Conditions 6 6 .3 10.8 Scour 6 3 .3 5.4 Subsurface Investigations 6 6 1 36 Settlement of STL Approach 4 3 1 12 Settlement of STC Approach 2 2 .5 2

B-4 Project Delivery Method: MoDOT performed an initial Risk Assessment on the I-64 Daniel Boone Bridge Project and determined that Design-Build Delivery Method was an appropriate delivery method for the project risks. The advantages of MoDOT’s innovative Design-Build contracting method are as follows: Design-Build (DB) contracts include design and construction under one contract, which is procured using a two-phased, contractor selection process. MoDOT scores proposals using a best value or “build-to-budget” scoring scenario. Nationally, Design- Build projects are completed 33 percent faster and 6 percent cheaper than conventional Design- Bid-Build. Contractual Provisions: Alternative Technical Concepts (Additional Applicable Standards): An Additional Applicable Standard (AAS) was received to request additional subsurface investigation, the proposers identified the potential for liquefaction in one of the abutments of the bridge. MoDOT performed and provided more borings to the proposers as a result. - Contractual clause extract: “3.5 Contents and Evaluation of Part 3 - Additional Applicable Standards and Proposer Defined Elements The Proposers shall meet MoDOT, AASHTO, and FHWA requirements unless alternative requirements are proposed and accepted by MoDOT and FHW A. The Proposers are encouraged to propose alternative technical requirements and Additional Applicable Standards for the Project that strive to meet or exceed the Project goals. All Additional Applicable Standards accepted by MoDOT and FHWA will be incorporated into Book 3 of the Contract Documents.

B-5 The Proposers shall provide the Additional Applicable Standards that include construction specifications, special provisions, design requirements (by discipline), standard drawings, materials and testing requirements, and manuals proposed for the Project.” Differing Site Conditions (DSC) clause: The contract includes a DSC clause but does not refer directly to the geotechnical studies provided by the owner. A change order was awarded to the contractor under this clause due to the finding of Metallic underground debris (sheet piles) and boulders near one of the bridge piers, which interfered with the foundation works. The impact of the change was an additional cost of $672,000.00 in the project cost and the additional resources that were required for the solution, which consisted in changing the sheet-pilling configuration to avoid the debris. The change is related to different subsurface conditions, which is directly related to the amount of investigation performed so it is considered a geotechnical-related change. - Contractual clause extract: “5.3 Process to be followed for Discovery of Certain Site Conditions 5.3.1 Notification to the Commission If the Contractor becomes aware of: (i) any on-Site material that the Contractor believes may contain Hazardous Substances that is required to be removed or treated (other than on-Site materials that are included in the re-use or beneficial use permits attached in Book 4) (ii) any human remains, artifacts, and/or other items of historical, archaeological or geological significance within the Right of Way; or (iii) any Differing Site Conditions, as a condition precedent to the Contractor’s right to a Change Order, the Contractor shall immediately notify the Commission thereof by telephone or in person, to be followed by written

B-6 notification as soon as practicable. The Contractor shall immediately stop Work and secure the area…” Agency approach to manage the geotechnical risk: The overall approach to manage the geotechnical risks in this project was to provide as much information as possible to the proposers in the form of a GBR. This includes performing additional borings -as requested by the proposers- before awarding. Additionally, the difference between available budget and the price of the awarded contract was allocated for contingencies and early completion incentives. During construction, the agency approached the debris problem by issuing a contractual modification under the DSC clause for $672,000.00, along with the supporting resources that were required for the solution which consisted in changing the sheet-pilling configuration to avoid the debris. The agency considers that the main geotechnical risk factor in DB contracts is the lack of a detailed design when the contract is awarded. In this case, the agency had to estimate the location of the piers or the final alignment of the bridge to perform the geotechnical studies Geotechnical risk considerations for DB projects: The agency considers that the main geotechnical risk factor in DB contracts is the lack of a detailed design when the contract is awarded. In this case, the agency had to estimate the location of the piers or the final alignment of the bridge to perform the geotechnical studies. The estimated location ended up being different than the final position of the foundation, hence the finding of unexpected underground debris. However, in order to manage geotechnical risk, Missouri DOT believes that the agency should provide as much information as reasonably possible and perform additional explorations required by the proposers.

B-7 Case Study 2: I-15/I-215 Interchange – San Bernardino, California This project was selected as a case study due to the highly complex geotechnical conditions that were identified and addressed prior to advertising the RFP. This project is located in an area between two major faults (San Andreas and Jacinto) and the geotechnical report that was prepared during preliminary engineering identified two potential faults within the project limits. Therefore, it was decided to perform a fault trench study to confirm the presence of a fault and estimate the degree of fault rupture. In addition, adequate subsurface explorations (borings) were conducted at strategic locations to help provide reasonable geotechnical parameters to the bidders. This was expected to reduce the geotechnical risks. Location: San Bernardino, California Award Year: 2012 Contract Amount: $208,000,000 Status: Completed Scope of work: The project consists of designing and building improvements to the I-15/I- 215 interchange by eliminating existing lane reductions on I-15, reducing operational issues due to weaving trucks, reducing interchange operational deficiencies such as non-standard design features, and correct arterial highway deficiencies. Geotechnical Risks: The project site is located in the highly seismic Southern California region within the influence of two fault system (San Jacinto and San Andreas) that are considered to be potentially active. The owner anticipates that the project site will periodically experience ground acceleration due to of small to moderate magnitude earthquakes. The geotechnical report prepared by the owner during the preliminary engineering design identified the two potential faults within the project limits as well. Project Delivery Method: Lump Sum, Best Value Design-Build.

B-8 Contractual Provisions: Alternative Technical Concepts: ATCs were received from non-winning proposers utilizing spread footings. - Contractual clause extract: “3.7 Alternative Technical Concepts Department has chosen to use the Alternative Technical Concepts (ATC) process set forth in this Section 3.7 to allow innovation and flexibility, to allow the design and construction to be completed together thereby minimizing conflicts and maximizing speed and efficiency, and ultimately to obtain the best value for the motoring public. Department will only entertain ATC submittals that propose alternatives to the following Books and Sections: Book 2, Section 10 Earthwork Book 2, Section 12 Drainage Book 2, Section 13 Structures Book 2, Section 18 Maintenance of Traffic Proposers may propose up to twelve (12) alternatives that are equal to or better in quality or effect as determined by Department in its sole discretion and that have been used elsewhere under comparable circumstances. Rejected ATCs and submitted ATCs that are deemed by Department to not qualify as an ATC are included in the maximum number of ATCs allowed.” Differing Site Conditions (DSC) clause: “Differing Site Conditions

B-9 (a) subsurface or latent physical conditions that differ from those reasonably assumed by Design-Builder based on incorrect boring logs provided in Book 2 to the extent that correct boring logs would have resulted in accurate assumptions, or (b) physical conditions of an unusual nature, differing materially from those ordinarily encountered at the Site and generally recognized as inherent in the Work provided for in the Contract, provided in all cases that Design-Builder had no actual or constructive knowledge of such conditions as of the Proposal Due Date. The foregoing definition shall not apply to Utilities, or Force Majeure events, nor shall it include any differences in groundwater depth or subsurface moisture content from that identified in the RFP. Clause (a) of this definition shall specifically exclude situations in which accurately reported boring data does not represent prevailing conditions in the area.” Agency approach to manage the geotechnical risk: Although this project was the first design-build project in their district, the agency knew that there was an inherent risk that needed to be dealt with. In order to manage the geotechnical risk, the agency decided to do a fault trench study to determine and confirm the presence of a fault and to estimate the degree of fault rupture. In addition, adequate subsurface exploration such as borings, were conducted at strategic location to help to provide reasonable geotechnical parameters to the proposers. Geotechnical risk considerations for DB projects: One main concern about geotechnical risk in DB projects is the lack of a comprehensive geotechnical design meaning that geotechnical parameters and data available are not complete and identified during the procurement phase. The agency also suggested that a project with significant geotechnical issues would be better served by

B-10 using design-bid-build or CM/GC contract. In the case of DB project, a detailed geotechnical exploration and design parameters should be provided up front prior to the release of the RFP. Case Study 3: PR 69 from Taylor Ridge Road to 1435 west of CR 750E– Greene County, Indiana This project was selected for a case study being a DB contract that had significant geotechnical challenges that were identified in the preliminary engineering. These arise from the geology of the site, consisting of bedrock hills with a thin layer of windblown and residual soils, which includes depositions during post-glacial recession of deep lacustrine deposits from the glacial slack water from tributaries to the White River valley. The construction in the valley included stage construction of embankments with high strength geotextile, ground modifications/improvements, Bridge with 13 spans spanning this valley and an array of geotechnical instrumentation monitoring. The variability of the soil profile and the combination of extremely high embankments with extremely weak soil made this project a good example of a geotechnically-complex DB project. Location: Greene County, Indiana Award Year: 2013 Contract Amount: $110,000,000 Status: Completed Scope of work: The project consisted of the construction of embankments with high strength geotextile, ground modifications/improvement (mandatory design), the construction of a bridge with 13 spans, and an array of geotechnical instrumentation monitoring which was a strong aspect of the design. Geotechnical Risks: The agency considered the project as a high geotechnical risk given the project site which is a valley. The geological profile not only was variable, but also was not

B-11 adequate to support future structures such as the combination of extremely high embankment with extremely weak soil. In addition, the design of environmental specifications to be made was considered as a geotechnical risk. Project Delivery Method: Originally, the project was procured as a DBB but the agency after having received complaints regarding the schedule and proposals to do activities as a DB delivery from bidders, the agency decided to procure the project as a DB. Contractual Provisions: Alternative Technical Concepts: Several ATCs were received from the proposers for this project with various objectives and methods, including 1) realignment of the structure to put all the bridge over the rock, 2) change the location of the embankment due to the ground conditions, 3) reduce the weight of the embankment, 4) replace the weak soil with borrow material for stabilization (Lime stabilization), 5) reduce the weight of the embankment by shifting the bridge 6) replace the weak soil with pea material. - Contractual clause extract: “DESIGN ALTERNATES The Design/Builder may schedule up to 2 design alternate meetings with the Department and their representatives for the purpose of proposing and discussing proprietary design alternates. The Department will review proposed design alternates and provide a written response to the Design/Builder. Proposed design alternates, except for proposed Traffic Control Plan alternates, shall not necessitate a revision to the Scope of Services, Special Provisions, or Specifications. Proposed design alternates discussed in design alternate meetings will be held confidential by the Department.

B-12 The Design/Builder shall present proposed concepts for variation to vertical and horizontal alignment shown in the contract plans, variations to median widths and variations to the Black Ankle Valley bridge at the Design Alternate Meetings. The Design/Builder may also propose revisions to the contract, including the Scope of Services, Special Provisions, or Specifications, for review by the Department. If approved, the Department may elect to revise the contract documents. Such revisions will be issued to all bidders prior to letting. The Design/Builder will be notified of approved and rejected proposed design alternates and proposed contract revisions. The decision of the Department will be final. The Design/Builder’s Project Schedule shall incorporate all major design and construction activities. Milestones shall include all witness and hold points, controlling items of work, intermediate completion dates, the contract completion date, contract closure periods and earliest or latest dates to start work. The schedule shall be shown in chronological order with the witness and hold points incorporated with the associated construction activities. The schedule shall indicate the critical path for completion of the project. During the course of design and construction of the project, the schedule shall be adjusted to reflect realistic anticipated progress of the project. The Design/Builder shall furnish updates of the schedule to the Engineer in accordance with the requirements herein.” Agency approach to manage the geotechnical risk: Knowing that the project was considered to have a high geotechnical risk profile, the agency approach was not only to conduct

B-13 as much geotechnical investigation is made as DBB project delivery, but also to do it right. INDOT consulted the geotechnical risk with its pre-qualified consultants, and specified a mandatory soil improvement design in the contract. Geotechnical risk considerations for DB projects: One consideration of INDOT to use DB delivery method is when the project requires innovation. Usually, a problematic area or significant issue is inherent to a non-common project. INDOT considers the lack of accurate and quality of geotechnical data and its interpretation as one of the main geotechnical factors associated with DB contracts. Case Study 4: I-15 Corridor Reconstruction Project – Salt Lake City, Utah This project was the first large Design-Build project developed by Utah DOT, it was selected for inclusion to illustrate the differences in managing the geotechnical risks as compared with a more recent case study in this research. The project consisted of reconstructing 16 miles of the I-15 Corridor in Salt Lake City, widening to five lanes each way by including a High Occupancy Vehicle (HOV) lane and a general purpose lane, the construction of a new interchange and significantly reconfigure all existing interchanges. The project was considered to have a high geotechnical risk due to the presence of soft compressive soil and the overall magnitude of the job. Location: Salt Lake City, Utah Award Year: 1997 Contract Amount: $1,600,000,000 Status: Completed Scope of work: The detailed scope of work is extracted from the contract as follows. “The I-15 Corridor Reconstruction project extends approximately 26 km (16 miles) from 10800 South to 600 North along the existing I-15 Corridor. The I-15 Mainline will be widened to

B-14 5 lanes in each direction with the addition of a high occupancy vehicle (HOV) lane and a general purpose lane. In selected areas, auxiliary lanes are to be added between interchanges. One new interchange will be added at 400 South. All existing interchanges and junctions will be significantly reconfigured. Most of the local street interchanges will be converted to “single point urban interchanges” (SPUI’s) from the existing “diamond” configuration. The exceptions are the interchanges at 10600 South and 1300 South. The reconstruction will include modifications to I-215 in the vicinity of 6400 South between State Street and 700 West; I-80 in the vicinity of 2400 South between State Street and I-15; State Route 201 from I-15 to a point just west of the Jordan River crossing; and I-80 in the vicinity of North Temple from I-15 to 1000 West. The project will include replacement or construction of all pavements and all structures (except the I-80 Eastbound bridges over 900 West and 1000 West and the 10600 South bridge over I-15) along the corridor, including the reconstruction of all of the interchanges, the railroad grade separation structures in the vicinity of 9000 South and 10600 South, and the 400 South, 500 South and 600 South and 600 North viaducts leading in and out of the Salt Lake City central business district. Numerous frontage roads and local streets will be modified, relocated and/or reconstructed along the corridor.” Geotechnical Risks: This project was considered to have a high geotechnical risk because the presence of soft compressive soil was identified in the preliminary studies, which creates the potential for settlement. Despite the accuracy of the information provided in the RFP, a change order had to be issued by the DOT after a claim was filed due to the occurrence of settlement in the structures adjacent to the project due to the weight of the embankment. The solution to the

B-15 problem was to redesign the embankment so the dimensions are reduced and the load on the soil lowered. Project Delivery Method: The decision to use DB was motivated by 1) the strong pressure from the public for completing the project as soon as possible to minimize the congestion time associated with traffic redirection on I-15, and 2) by the need to have the project completed before the 2002 Winter Olympics that were to be hosted in Salt Lake City. DB was selected as the appropriate project delivery method to accomplish those goals. Contractual Provisions: Alternative Technical Concepts: “3.3.8.1 Technical Concept Review Each proposer may submit its technical concepts for aesthetics, pavement, structures, geotechnical design and construction, and maintenance of traffic to the Department between October 23 and December 1, 1996 for initial review and comment. The Proposer may also submit proposed changes to the Phase I design basic alignment configuration and its work breakdown structure and Baseline Plan concepts. Submit the Technical Concepts to the address shown in RFP Section 3.3.9.1. The review of concepts will be “blind”; i.e., those reviewing the concepts will not know the identity of the proposer(s). See RFP Section 3.4.2 for instructions. The proposer shall submit five (5) copies of each technical concept identified by a separate cover letter that identifies the proposer. See Form 0, Technical Concepts Cover Sheet. No information on text or drawings shall identify the Proposer or any member of its organization. If the information is provided in 3-ring binders, the binders shall be plain with no names, graphics, symbols, or logos appearing on the binders.

B-16 Department comments will be limited to a statement that the proposer’s approach appears to be generally acceptable and within the requirements of the RFP documents, or identification of areas in which the approach appears to be inconsistent with the RFP requirements. Department comments will be returned to the proposer not later than two (2) weeks after receipt of the concepts. The contents of the technical concepts package and all communications regarding such concepts will be kept in the strictest confidence, subject to the provisions in RFP Section 3.2.5 pertaining to future use of ideas submitted by proposers who receive the stipend. 3.3.10.1.2 Geotechnical The proposal shall address: a) Geotechnical design  Earthwork  Embankments (i.e. types, material source, quality and stability)  Settlements (i.e. total, differential, secondary, monitoring and mitigation plans)  Walls (i.e. types, foundation systems, settlements and stability)  Fondation types (i.e., pile, caissons, etc.) and installation techniques” Differing Site Conditions (DSC) clause: “13.9 Differing Site Conditions, Utilities and Certain Force Majeure Events 13.9.1 Differing Site Conditions. Subject to the limitations contained in this Section 13.9, and upon Contractor’s fulfillment of the requirements of this Section 13 regarding requests for Change Orders, Department

B-17 shall be responsible for, and agrees to issue Change Orders for additional costs due to changes in the Work directly attributable to Differing Site Conditions and not reasonably avoidable by Contractor. 13.9.1.1 Burden of Proof. Contractor shall bear the burden of proving that a Differing Site Condition exists and that it could not reasonably have worked around the Differing Site Condition so as to avoid additional cost. Each request for a Change Order under this Section 13.9.1 shall be accompanied by a statement signed by a qualified professional setting forth all relevant assumptions made by Contractor with respect to the condition of the Site, justifying the basis for such assumptions and explaining exactly how the existing conditions differ from those assumptions, and stating the efforts undertaken by Contractor to find alternative design or construction solutions to eliminate or minimize the problem and the associated costs. For Differing Site Conditions involving Utilities, Contractor shall describe the nature of the investigations undertaken under Section 6.6.1.1 hereof and explain why it could not have been expected to discover such Utility in the course of its investigations.” Agency approach to manage the geotechnical risk: Being their first large DB project, UDOT approached the geotechnical risk by providing a GDR including nearly 100% AASHTO standard borings which they consider uncommon for a project delivered under the DB scheme. During the construction, it was found that approximately 95% of the data was within 5%-7% variation from the actual conditions on the site. Additionally, having identified the risk of settlement in the preliminary studies, UDOT decided to increase the settlement warranty requirement for this project to three years instead of their standard two years.

B-18 Case Study 5: I-15 SR-73 Pioneer Crossing – Lehi, Utah This project is the second case study obtained from Utah DOT and is particularly interesting to this research to illustrate how geotechnical risks are currently being handled as compared to their first large DB project in 1996, the I-15 Corridor Reconstruction Project in Salt Lake City. This project was not initially identified as one with a high geotechnical risk, but the presence of a wetland in the area combined with the implementation of an ATC increased the risk and ended up requiring a geotechnical-related change order. Location: Lehi, Utah Award Year: 2009 Contract Amount: $282,361,000 Status: Completed Scope of work (contract extract): “Pioneer Crossing includes six miles of a new east-west connector from American Fork Main Street through Lehi to Redwood Road in Saratoga Springs. Project features include a new Diverging Diamond Interchange, a new 60-in. waterline for the Central Utah Water Conservancy District, a 5- to 7-lane urban arterial with PCCP pavement, new bridges over the Jordan River and Union Pacific Railroad, new concrete box culverts at the Dry Creek and Lehi Trail crossing, noise walls, retaining walls, aesthetics/landscaping, drainage, utility relocations, ATMS, and traffic signal work. The innovative Diverging Diamond Interchange (DDI) Bridge at I-15 replaces the existing diamond interchange and includes new ramps and I-15 widening. The DDI, which includes twin, two-span pre-stressed concrete girder structures replacing an existing four-span structure over I-15, is a unique innovation in transportation design. The four individual spans have a maximum length of 190 feet and weigh approximately 2,300 tons each.”

B-19 Geotechnical Risks: This project was not considered to have particularly high geotechnical risks when estimated by UDOT. The presence of a wetland was identified but the original alignment was not intended to use that area. During the procurement process, an ATC was received to shift the alignment. The ATC was approved but the new alignment did cross through the wetland area resulting in encountering soft soil conditions which led to a claim that was settled in favor of the contractor by means of a contractual change order. Project Delivery Method: The delivery method selected for this project is Design-Build with lump sum compensation method. Design-Build is selected by UDOT when the design will take too much time or due to loss of expertise in the DOT. Contractual Provisions: Alternative Technical Concepts: An ATC was received in this project that resulted in an alignment shift in one of the bridges. The new alignment crossed over a wetland area and presented technical challenges due to soft soil conditions, which were addressed in a contractual change order based on the Differing Site Conditions clause after the contractor presented a claim. - Contractual clause extract: “ITP.3.1 ATC GOALS AND ELIGIBILITY Sections ITP.3.1 through 3.2 set forth a process for pre-Proposal review of Alternative Technical Concepts (ATCs) that conflict with the requirements for design and construction of the Project, or otherwise require a modification of the technical requirements of the Project. This process is intended to: (A) Allow Proposers to incorporate innovation and creativity into the Proposals;

B-20 (B) Allow the Department to consider Proposer ATCs in making the selection decision; (C) Avoid delays and potential conflicts in the design associated with the deferring of reviews of ATCs to the post-award period; and (D) Obtain the best value for the public. ATCs eligible for consideration hereunder shall be limited to those deviations from the requirements of the as-issued Contract Documents that result in performance and quality of the end product that is equal to or better than the performance and quality of the end product absent the deviation, as determined by the Department in its sole discretion. A concept is not eligible for consideration as an ATC if, in the Department’s sole judgment, it is premised upon or would require: (A) A reduction in Project scope, performance, or reliability; (B) The addition of a separate Department project to the Contract (such as expansion of the scope of the Project to include additional roadways); or (C) An increase in the amount of time required for Substantial Completion. Any ATC that, if implemented, would require further environmental evaluation of the Project, may be allowed, provided that the Proposer will bear the schedule and cost risk associated with such additional environmental evaluation. If the Proposer is not able to obtain the approvals necessary to implement the ATC, the Proposer will be obligated to develop the Project in accordance with existing approvals and without additional cost or extension of time.

B-21 Any ATC that has been pre-approved may be included in the Project, subject to the conditions set forth herein. If a Proposer is unsure whether a concept is consistent with the requirements of the RFP or if that concept would be considered an ATC by the Department, the Department recommends that Proposer submit such a concept for review as an ATC.” Differing Site Conditions (DSC) clause: The DSC clause was used in this project to compensate the contractor for improving poor soil conditions that weren’t properly identified in the new alignment on one of the bridges. - Contractual clause extracts: “Definition: Differing Site Conditions: Subsurface or latent physical conditions at the Project site that (a) differ materially from those indicated in the Contract, or (b) unforeseen physical conditions that differ materially from those ordinarily encountered at the geographical location where they were discovered; provided that such conditions could not have been discovered by reasonable site investigation or review of other available information prior to the Proposal Due Date. The term “Differing Site Conditions” specifically excludes variations in soil moisture content from that represented in reports, borings, or tests conducted by the Department and included in the Contract Documents.” “1.8 DIFFERING SITE CONDITIONS, CHANGES, AND REQUESTS OR CLAIMS FOR ADDITIONAL COMPENSATION

B-22 A. Immediately notify the Department verbally of alleged changes to the Contract due to Differing Site Conditions. Verbal notice of Differing Site Conditions shall be promptly followed by written notice. 1. Leave the site undisturbed and suspend Work unless directed otherwise when Differing Site Conditions on the Project are encountered; 2. Obtain written authorization from the Department to perform affected Work and incur expense for Contract items after discovering the change, condition, or event; 3. Site conditions to report include: a. Conditions differing materially from those indicated in the Contract; b. Unforeseen physical conditions that differ materially from those ordinarily encountered at the geographical location where they were discovered; provided that such conditions could not have been discovered by reasonable site investigation or review of other available information prior to the Proposal Due Date; and c. Circumstances or occurrences that may result in a request for additional Contract Time or monetary compensation. 4. Failure to provide required notice under this Article 1.8 constitutes a waiver for any claim resulting from the alleged change, condition, or event; and 5. If the site conditions indicated from the Design-Builder’s site exploration in any area differ materially from the conditions indicated in the Contract for such area, the notification required by Article 1.8.A.4.a

B-23 shall be made promptly after completion of the site exploration in the area, and the Plans shall be based on the conditions as identified in such exploration. B. To request additional time or compensation, follow the requirements set forth in Section 1282S, Article 9. Contract adjustment is made as written modification to the Contract through Change Order when warranted, in accordance with and subject to the limitations and restrictions set forth in Article 9 of Section 01282S. C. No claim may be made for Differing Site Conditions under Article 1.8.A.4.b. if a reasonable site investigation and exploration during the pre-construction phase would have indicated the condition. D. The Design-Builder shall bear the burden of proving that a Differing Site Condition exists and that it could not reasonably have designed the Project or worked around the Differing Site Condition so as to avoid additional cost. E. For equitable adjustments relating to existing utilities at the Site, the provisions of this Article 1.8 is subject to Article 1.9.” Agency approach to manage the geotechnical risk: UDOT provided a Geotechnical Data Report (GDR) in the contract with an estimated cost of 0.5% of the total project amount and dedicate around six (6) months to perform the preliminary studies. Additional studies are allowed to be performed by the proposers if requested, which did not occur in this project. Along with the GDR and the contractual provisions for ATCs and the DSC clause, UDOT provided specifications that had to be followed to mitigate differential settlement and also required at least 2 years of warranty against settlement.

B-24 Geotechnical risk considerations for DB projects: UDOT’s opinion stands that liquefaction and seismic-related risks could preclude a project from being DB delivery method given that the effect of these risks will not be apparent during construction or the warranty period. Therefore, the design-builder might attempt to ignore those risks. Case Study 6: Horseshoe Project – Dallas, Texas This project was selected for inclusion due to the complex foundation work and high geotechnical risk involved, and the selected project delivery method where the majority of work is to be performed as a Design-Build Project but one of its components, the Margaret McDermontt Bridges designed by Santiago Calatrava, was a Design-Bid-Build portion within the project. The geotechnical conditions of the site along with the design of the Margaret McDermontt Bridges presented challenges and required a contractual change order. The contractor proposed an ATC before winning the contract to use a different correlation chart to design the drilled shaft based on site-collected data. Figure B.1 shows a plan view of the project with all its components. Location: Dallas, Texas Award Year: 2012 Contract Amount: $818,000,000 Status: Completed Scope of work: The U-shaped $818 million bridge and roadway project near Dallas’ Central Business District is referred to as The Horseshoe Project. TxDOT will replace bridges that cross the Trinity River on Interstate 30 and I-35E, as well as upgrade the connecting roads just south of downtown Dallas. The Horseshoe improves safety and increases capacity on these bridges and roadways, which are central to the vitality of the Dallas economy.

B-25 Figure B.1 - Plan View of Dallas Horseshoe Project Project components: - Replace bridges that cross Trinity River on I-30 and I-35E - Connect roadways where they converge near the downtown Dallas Central Business District - Upgrade outdated roadway design improving safety, and increasing capacity and mobility - Meets the North Central Texas Council of Governments 2035 Metropolitan Transportation Plan (MTP) Geotechnical Risks: This project is considered to have high geotechnical risks due to the high uncertainty related to presence of around 30 to 40 feet of loose clay and soft soil (poor soil conditions) in the site. These conditions present a challenge, especially for the foundations of the Margaret McDermott Bridges due to their inclined design.

B-26 Project Delivery Method: The Project Delivery Method used is Design-Build with the exception of the Margaret McDermott Bridges, for which the design was developed by the owner and provided in the specifications (Design-Bid-Build). Although it was not used on this project, TxDOT has implemented a Project Delivery Method Selection Tool based on TCRP Report 131. TxDOT, FHWA and the consulting industry participated in the development of the model. The tool suggests a delivery method and the PM has to get approval from the Transportation Commission. Contractual Provisions: Alternative Technical Concepts: There was a geotechnical-related ATC in this project, the contractor proposed to create a new correlation chart for Allowable Skin Friction vs Texas Cone Penetrometer by performing pilot drilled shafts in three locations, test them and use that data to create a new chart instead of the chart provided in TxDOT’s geotechnical manual. TxDOT agreed to the proposal with the condition that the contractor must use the new chart even if it is more conservative than the one in the manual. After the tests were performed (with the contract awarded), the chart ended up being more conservative than TxDOT’s, therefore, the contractor had to use the new chart and absorb the costs of designing more conservatively. - Contractual clause extract: 3.1 Alternative Technical Concepts “Alternative Technical Concepts,” or “ATCs,” are concepts that conflict with the requirements for design, construction, and capital maintenance of the Project or otherwise require a modification of the Technical Provisions but that may

B-27 nevertheless be proposed in accordance with the terms and conditions set forth in this ITP. Sections 3.1 through 3.5 set forth the process for pre-Proposal review of ATCs. This process is intended to allow Proposers to incorporate innovation and creativity into the Proposals, in turn allowing TxDOT to consider Proposer ATCs in making the selection decision, to avoid delays and potential conflicts in the design associated with deferring of reviews of ATCs to the post-award period, and, ultimately, to obtain the best value for the public. ATCs eligible for consideration hereunder shall be limited to those deviations from the requirements of the as-issued DBA Documents and CMA Documents that result in performance and quality of the end product that is equal to or better than the performance and quality of the end product absent the deviation, as determined by TxDOT in its sole discretion. A concept is not eligible for consideration as an ATC if, in TxDOT’s sole judgment, it is premised upon or would require (a) a reduction in Project scope, performance or reliability; (b) the addition of a separate TxDOT project to the DBA or CMA (such as expansion of the scope of the Project to include additional roadways); or (c) an increase in the amount of time required for Substantial Completion of the Work under the DBA. ATCs that, if implemented, would require further environmental evaluation of the Project, may be allowed; provided, however, that DB Contractor will bear the schedule and cost risk associated with such additional environmental evaluation. If DB Contractor is not able to obtain the approvals necessary to implement the ATC, DB Contractor will be obligated to

B-28 develop the Project in accordance with existing approvals without additional cost or extension of time. Any ATC that has been pre-approved may be included in the Proposal, subject to the conditions set forth herein. If a Proposer is unsure whether a concept is consistent with the requirements of the RFP or if that concept would be considered an ATC by TxDOT, TxDOT recommends that Proposer submit such concept for review as an ATC. Differing Site Conditions (DSC) clause: “13.8.1 Differing Site Conditions Subject to the restrictions and limitations set forth in this Section 13, DB Contractor shall be entitled to a Change Order for certain additional costs which are directly attributable to any Differing Site Conditions to the extent permitted in this Section 13.8.1. No time extension shall be available with respect to Differing Site Conditions, and no delay or disruption damages shall be recovered. To the extent that additional costs are incurred in connection with the Project due to changes in DB Contractor’s obligations relating to the Work resulting from the existence of Differing Site Conditions and which are not reimbursed by insurance proceeds, TxDOT and DB Contractor shall share the risk as follows: DB Contractor shall be fully responsible 13.8.1.1. for, and thus shall not receive a Change Order with respect to, the first $150,000 in additional costs incurred directly attributable to changes in DB Contractor’s obligations hereunder resulting from each separate occurrence of Differing Site Conditions, subject to an aggregate cap of $2,100,000 for such

B-29 additional costs resulting from the $150,000 “deductible” amounts borne by DB Contractor. 13.8.1.2. TxDOT shall be fully responsible for any additional costs incurred in excess of (1) $150,000 directly attributable to changes in DB Contractor’s obligations hereunder resulting from each separate occurrence of Differing Site Conditions, and (2) the $2,100,000 cap described in Section 13.8.1.1, and a Change Order shall be issued to compensate DB Contractor for such additional costs. 13.8.1.3. During progress of the Work, if Differing Site Conditions are encountered, DB Contractor shall immediately notify TxDOT thereof telephonically or in person, to be followed immediately by written notification. DB Contractor shall be responsible for determining the appropriate action to be undertaken, subject to concurrence by TxDOT. In the event that any Governmental Approvals specify a procedure to be followed, DB Contractor shall follow the procedure set forth in the Governmental Approvals. 13.8.1.4. DB Contractor hereby acknowledges and agrees that it has assumed all risks with respect to the need to work around locations impacted by Differing Site Conditions. DB Contractor shall bear the burden of proving that a Differing Site Condition exists and that it could not reasonably have worked around the Differing Site Condition so as to avoid additional cost. DB Contractor shall track the first $150,000 in costs associated with a Differing Site Condition in accordance with the requirements and limitations in Section 13.7 and shall track the costs incurred in excess of $150,000 in accordance with the requirements and limitations in Section 13.6.

B-30 13.8.1.5. Each request for a Change Order relating to a Differing Site Condition shall be accompanied by a statement signed by a qualified professional setting forth all relevant assumptions made by DB Contractor with respect to the condition of the Site, justifying the basis for such assumptions, explaining exactly how the existing conditions differ from those assumptions, and stating the efforts undertaken by DB Contractor to find alternative design or construction solutions to eliminate or minimize the problem and the associated costs. No time extension or costs will be allowed in connection with any work stoppage in affected areas during the investigation period described above.” Changes to the Margaret McDermont Bridges: “13.8.5 Bridges Design Change If a Change Order is necessary due to a Margaret McDermott Bridges Design Change as described in Section 4.4.3 other than a DB Contractor-Initiated Margaret McDermott Bridges Design Change, and upon DB Contractor’s fulfillment of all applicable requirements of this Section 13 and subject to the limitations in this Section 13 and the other provisions of this Agreement, TxDOT shall issue Change Orders: (a) to extend the Completion Deadlines for Segment B, as applicable, as the result of any delay in a Critical Path for the Margaret McDermott Bike/Pedestrian Bridges caused by such Margaret McDermott Bridges Design Change, to the extent that it is not possible to work around such change; and (b) to compensate DB Contractor for additional costs incurred directly attributable to such Margaret McDermott Bridges Design Change in accordance with Section 13.8.5.1 below. 13.8.5.1. Determination of Reimbursable Amount

B-31 Except as otherwise provided and subject to the limitations in this Section 13.8 and other provisions of this Agreement, TxDOT shall be responsible for the aggregate additional construction costs incurred by DB Contractor directly attributable to such Margaret McDermott Bridges Design Change, such that a Change Order will be issued in the amount of 100% of such additional costs. In determining whether a Change Order is allowed under this Section 13.8.5, DB Contractor shall bear the burden of proving that all costs incurred are reasonable and necessary and could not have been avoided by reasonable construction techniques.” Agency approach to manage the geotechnical risk: Given the inherent geotechnical risk, TxDOT procured the project as a DB delivery in order to encourage innovation. In addition, TxDOT managed the geotechnical risk by not limiting geotechnical investigations to be performed by the contractor, promoting the proposal of ATCs, and letting the contractor decide on geotechnical solutions like using a bridge instead of a retaining wall. However, some mandatory design parameters are included as a mitigation action, such as standard pavement designs and a full geotechnical manual that has to be followed except for approved ATCs as occurred in this project (Allowable Skin Friction vs Texas Cone Penetrometer Chart). TxDOT also included liability caps to the DSC clause to clearly establish the shared responsibility of the geotechnical risks and incorporated two notices to proceed (NTP) in the contract; the first NTP included preliminary work and studies, and the second NTP corresponds to all other work pertaining the Project. The contract language is detailed as follows: “4.1.3 TxDOT anticipates issuing NTP1 concurrently with execution and delivery of this Agreement. Issuance of NTP1 authorizes DB Contractor to perform (or, continue performance of) the portion of the Work necessary to obtain TxDOT’s approval of the component parts, plans and

B-32 documentation of the Project Management Plan that are labeled “A” in the column titled “Required By” in Attachment 2-1 to the Technical Provisions. It also authorizes DB Contractor to enter Project Right of Way owned by TxDOT for the purpose of conducting surveys and site investigations, including geotechnical, Hazardous Materials and Utilities investigations. Refer to Sections 12.1.4 and 15.9 regarding a Price adjustment to be made in certain circumstances if the effective date of the NTP1 is later than 180 days after the Proposal Due Date, and regarding DB Contractor’s remedies for certain delays in issuance of NTP1 beyond 365 days after the Effective Date. 4.1.4 TxDOT anticipates issuing NTP2 concurrently with TxDOT’s approval of all the foregoing component parts, plans and documentation of the Project Management Plan and the Project Schedule. Issuance of NTP2 authorizes DB Contractor to perform all other Work and activities pertaining to the Project.” Geotechnical risk considerations for DB projects: TxDOT expressed that major unforeseen geotechnical conditions and hazardous material are the main risk factors associated with DB delivery, and the existence of hazardous materials could cause to advise against delivering projects using DB. In this project, the costs related to treating Hazardous Materials were shared. Case Study 7: Innovative Congestion Management Project – Montgomery and Frederick Counties, Maryland This project was selected for inclusion to analyze the benefits of delivering a project using Progressive Design-Build, a new concept in transportation projects. This new project being procured by Maryland DOT has the potential to eliminate the inherent risk associated with decision-making based on one-sided preliminary geotechnical studies by segmenting the project

B-33 and progressively issue notices to proceed as preliminary studies and design advance under a guaranteed maximum price. Location: Montgomery and Frederick Counties, Maryland Award Year: 2017 (Est.) Contract Amount: $100,000,000 Status: Not awarded Scope of work: The project consists of a 32-mile corridor, there is no specified scope of work in the RFQ, but mobility, operation and safety are the overall goals. What follows is an extract from the RFP: “The project area is the IS 270 corridor from IS 495 (including the IS 270 spur) to IS 70. The study corridor is one of the most congested in Maryland with average daily traffic of approximately 240,000 in many segments. Over saturated conditions and extended peak periods greatly impact reliability. The inside travel lane of IS 270 functions as a High Occupancy Vehicle (HOV) lane from 6:00 am to 9:00 am in the southbound directions from IS 370 to IS 495 and from 3:30 pm to 6:30 pm in the northbound direction from IS 495 to MD 121. It is expected that the HOV usage will be required to be maintained for any future project. The SHA is developing a contract to solicit a Design-Builder to reduce congestion and improve reliability along the IS 270 corridor. The SHA has not developed any preferred solutions, but is looking for the engineering and construction industries to provide implementable and innovative solutions to increase vehicle throughput, reduce delay and increase reliability along IS 270 within the project’s budget. The current budget for the project is $100,000,000. This includes all work for the project including design, right-of-way acquisition, utility relocations, construction services, and construction management services. The budget for the Design-Build contract has not been established, but is anticipated to be in the high-$70 to low $80 million range.

B-34 The SHA has developed goals for the project. The goals are as follows: 1. Mobility – Provide improvements that maximize vehicle throughput, minimize vehicle travel times, and create a more predictable commuter trip along I-270. 2. Safety – Provide for a safer I-270 corridor. 3. Operability/Maintainability/Adaptability – Provide improvements that minimize SHA operations and maintenance activities while being adaptable to future transportation technological advancements. 4. Well-Managed Project – Provide a Project Management and Work Plan that addresses communications, coordination and risk management, achieves a collaborative partnership with all members of the project team and stakeholders, and successfully advances the project goals.” Geotechnical Risks: Given that this project is procured using Progressive DB, the design- builder and the owner have flexibility to vary the geotechnical scope of the project. This project is considered as a common project with regards of the geotechnical risk. Considering that the contract has not been awarded at the moment of this study and the scope is very broad at this point; there are no specific geotechnical risks identified. Project Delivery Method: This project is the first time that the agency implements Progressive DB, the objective is to encourage innovation from the industry in collaboration with the DOT. “This Progressive Design-Build (PDB) contract is a two-phase, fixed value contract. Phase one of the contract will be for the selected Design-Builder to provide Design and Preconstruction Services to SHA to develop the project to the level necessary to submit a price for construction for work packages proposed by the Design-Builder.

B-35 Once the design has been completed to the necessary level for any work package to submit a price, the SHA will attempt to reconcile a Construction Agreed Price (CAP) for the construction of that work package. As multiple packages are allowed and anticipated, multiple CAPs may be agreed upon as long as the overall sum of all CAPs does not exceed the contract’s fixed value. If the SHA agrees to a CAP, then notice to proceed for phase two construction services would be issued for that package. The SHA reserves the right to not proceed with phase two of the contract and bid a package competitively if a CAP cannot be reached. If SHA chooses to deliver the project by other means, the selected Design-Builder will not be permitted to submit a proposal or bid. The intent is to form a partnership with the owner (SHA) and the Design-Builder. The goals of this partnership are to mitigate risk, streamline the design process, improve the decision-making process with better information, and develop a project that meets the project goals while adhering to the budget. We anticipate the involvement of the Design- Builder will help reduce errors in design, maximize the achievement of project goals, improve the overall constructability of the project and support the Practical Design process. The fixed value of the contract is an aggregate of the Design-Builder’s Design and Preconstruction Services Fee, the Design-Builder’s Construction Management Fee, and the Construction Services Costs. Construction services will include all CAPs, costs for any necessary right-of-way acquisition, and costs for any utility relocations required due to the construction of the contract. The fixed value of the contract will be $100,000,000. When right-of-way acquisition is required, the Administration will establish the right-of- way costs based on the needs established by the Design-Builder. All costs for right-of-way acquisition will be subtracted from the established cost for Construction services. Right-of-way acquisition services are expected to be completed by the Administration; however, the

B-36 Administration will consider placing acquisition services on the Design-Builder if agreed upon in the development of a CAP. When utility relocations are required, the Administration will establish relocation costs for utilities to be relocated by parties other than the Design-Builder. Any costs for utility relocations to be performed by the Design-Builder will be included in any CAP. All costs for utility relocations will be subtracted from the established cost for Construction services. Early procurement or construction work may be considered for acquisition of long lead items or to complete early construction tasks that can be completed and turned over to another Design-Builder or Contractor, should a CAP for final construction not be agreed upon. Early right-of-way acquisition, utility work or construction work may be considered with the understanding that early phases are not a guarantee of agreement of a CAP for final construction. Early phases must be independent and severable from the final construction package, with well- defined end point. Construction will not begin until a CAP has been accepted for a Plans, Specifications & Estimates (PS&E) package.” Contractual Provisions: Alternative Technical Concepts (contract extract): Proposed Technical Concepts (PTC): “As part of the second step, the RCL may submit Proposed Technical Concepts (PTCs) to the Administration for review. The PTC process allows each Proposer to submit solutions it may propose in the Technical Proposal for Administration feedback. This process is intended to assist the Proposers in best determining which concepts it will propose for implementation in its Technical Proposal.”

B-37 RFQ page 21: “A stipend in the amount of $750,000.00 may be paid to a Proposer not meeting either of the above conditions if the Proposer has a Proposed Technical Concept (PTC) the Administration wishes to utilize in the final design.” Differing Site Conditions (DSC) clause: Standard differing site conditions clause. Since the DB company is taking on the engineering responsibilities as well, the DOT thinks that their risk is minimal. The DB company is responsible for “all” risks. Agency approach to manage the geotechnical risk: The agency considers that there should be a balance in the amount of information that is given to contractors, as too much information or interpretation can give foundations for change orders during the project execution. Giving the DB additional information could reduce the initial cost but cause a change order down the line. Additionally, a scope validation period is incorporated in the contract to allow the contractor to incorporate any differing site conditions early in the project. “Geotechnical The Administration has performed ground penetrating radar (GPR) and obtained soil borings on existing shoulders at selected locations along the project corridor (refer to appendices for locations) and performed laboratory testing of the samples. The boring logs and laboratory test data are included on ProjectWise. Pavement history has been collected and provided as supplemental information. Soils information from the Watkins Mill Interchange Project is also included on ProjectWise. These studies were performed with reasonable care and recorded in good faith. The Administration considers the information Engineering Data and will stand behind its accuracy at

B-38 the location studied. The Administration assumes no responsibility in respect to the sufficiency of the studies for design. The Design-Builder will need to perform additional geotechnical testing and analysis to complete the project. The Design-Builder is responsible for performing a complete geotechnical program including additional borings, sampling, in-situ and laboratory testing, analysis, and design, as necessary to complete design and construction.” “Scope Validation and Identification of Scope Issues A Scope Validation Period of 120 days from the date of the Notice to Proceed for Design and Preconstruction Services will be provided on this contract. During the Scope Validation Period, the Design-Builder shall thoroughly verify and validate that the Design-Builder’s understanding of the scope of work and its ability to complete it within the Design and Preconstruction Services Fee. Any Scope Issues determined during this period shall not be deemed to include items that the Design-Builder should have reasonably discovered prior to submission of its Technical Proposal. If the Design-Builder intends to seek an adjustment to the Design and Preconstruction Fee due to a Scope Issue, it shall promptly, but in no event later than the expiration of the Scope Validation Period, provide the Administration in writing with a notice of the existence of such Scope Issue and basis for such Scope Issue. Within 30 days of the notice, the Design-Builder shall provide documentation that specifically explains its support for the Scope Issue, which shall include among other things: (a) the assumptions the Design-Builder made during the preparation of its Proposal that form the basis of its allegation, along with documentation verifying it made such assumptions in developing its Proposal; (b) explanation of the Scope Issue that the Design- Builder could not have reasonably identified prior to submission of the Technical Proposal; (c)

B-39 specific impact on the Design and Preconstruction Services. For the avoidance of doubt: (1) The Design-Builder shall not be entitled to raise any Scope Issues that were not previously addressed with a notice; and (2) Design-Builder shall have no right to seek any relief for any Scope Issues not identified in a notice provided to the Administration during the Scope Validation Period. Within a reasonable time after the Administration’s receipt of the documentation, the parties shall meet and confer to discuss the resolution of such Scope Issues. If the Administration agrees that the Design-Builder has identified a valid Scope Issue, a change order will be executed to increase the value of the Design and Preconstruction Fee; however, the Construction services will be adjusted to retain the overall fixed value of the contract. Notwithstanding anything to the contrary in the Contract Documents or a matter of law, the Design-Builder shall have the burden of proving that the alleged Scope Issue could not have reasonably been identified prior to the submission of the Technical Proposal and such Scope Issue materially impacts its Design and Preconstruction Services Fee. The parties acknowledge that the purpose of the Scope Validation Period is to enable the Design-Builder to identify those Scope Issues that could not have reasonably been identified prior to the submission of the Technical Proposal. By submission of the Technical Proposal, the Design- Builder acknowledges that the Scope Validation Period is a reasonable time to enable the Design- Builder to identify Scope Issues that materially impacts its Design and Preconstruction Fee. The Design-Builder will assume and accept all risks to complete the Design and Preconstruction Services at the conclusion of the Scope Validation Period without any change in the fee absent any change to the Contract requirements after the completion of the Scope Validation Period.”

B-40 Geotechnical risk considerations for DB projects: According to the interviewee, the major disadvantage of DB delivery is the loss of DOT control on the project. Public considerations can be sensitive when working on projects near park or areas of public interest. Schedule and scope can also be negative factors that could go against the use of DB. The agency perceives that giving additional geotechnical information could reduce the initial cost but might cause a change order down the line. Case Study 8: Columbus Crossroad - Project 1 – Columbus, Ohio This project was the first of two selected as case studies to illustrate the way the Ohio DOT manages large DB projects with regards of geotechnical risks. The project is considered to have a high geotechnical risk due to its magnitude, and there were some significant considerations such as the need for dewatering due to a high water table, and the contractual requirement for a baseline tunneling report for micro tunneling work. Location: Columbus, Ohio Award Year: 2011 Contract Amount: $200,350,000 Status: Completed Scope of work: The work involved realignment of l-670 EB so through traffic stays to the left and traffic to I-71 exits to the right and work on I-71 from over Jack Gibbs to Long Street. Includes 21 mainline, ramp and overhead bridges. Includes one bridge cap on Spring St and two bridge caps on Long St. Geotechnical Risks: Given the overall size of the project, the geotechnical risk was considered higher compared to other projects. In addition, other risks were the high water table on

B-41 northern section of project, the required dewatering to occur prior to construction, the micro tunnel required with location of pre-determined receiving pits. The location of the project was categorized as: Below the pavement and topsoil layers, the borings encountered primarily medium dense to very dense sand and gravel consisting of gravel (a-1-a), Gravel with sand {a-1-b), fine sand (a-3) and coarse and fine sand {a-3a) With lesser amounts of gravel with sand and silt (a-2-4) and gravel with sand, silt, and clay (a-2-6). Hea vino sands were also encountered generally below depths of 15.0 feet. Conditions of specific layers were of quality and gradation that it met the requirements of MSE wall backfill. Contractor did utilize on-site materials for MSE walls with synthetic reinforcement (Tensar). Project Delivery Method: The Project was to be the first of the Columbus Crossroads project. Funding came available through ARRA funding. Accelerated delivery was required, therefore a DB project delivery was utilized. Contractual Provisions: Alternative Technical Concepts: An ATC was received for the Microtunnel Manhole Spacing: the preliminary plan and profile shows a spacing of greater than 500 ft between the jacking and receiving pits, with each pit containing a manhole. One pipe run between pits/manholes measures 1371 ft. When the tunnel is complete, additional manholes will have to be "doghoused" on the microtunnel. The installation will be difficult and will require additional maintenance of traffic and shoring to handle deep excavations. Differing Site Conditions (DSC) clause: “104. 02.B Differing Site Conditions. Notify the Engineer as specified in C&MS 104. 05 upon discovery of any of the following conditions:

B-42 1) Subsurface or latent physical conditions at the site differing materially from those indicated in the Contract Documents and are not discoverable from an investigation and analysis of the site by the DBT meeting the standard of care for such an investigation and analysis. 2) Unknown physical conditions of an unusual nature differing materially from those ordinarily encountered and generally recognized as inherent in the Work provided for in the Contract Documents, are encountered at the site. Provide required notification before disturbing any differing site condition. Irrespective of the previous paragraph, the following will not be considered Differing Site Conditions for purposes of this section: Work involving utility relocations or utility coordination. This work will be addressed in accordance with the Project Scope. Section 6. Upon notification from the DBT, the Engineer will investigate potential differing site conditions. The Engineer will determine if differing site conditions have been encountered and notify the DBT of the Department's determination. If the Department determines that conditions materially differ and cause an increase or decrease in the cost or time required for the performance of any Work under the Contract, the Department will make an adjustment and modify the Contract as specified in CMS 109.05 and as follows: 1) The first $250.000 of direct costs and associated impact will be the responsibility of the DBT.

B-43 2) All costs which exceed the amount identified in item #1 above will be computed and paid to the DBT without any markup. The Department acknowledged differing site condition Work is excusable, compensable, as defined by CMS 108.06 D except as noted in this section.” Agency approach to manage the geotechnical risk: The first $250,000 of differing site conditions was to be considered incidental. Micro Tunnel required with location of pre-determined receiving pits defined. Requirement to provide a geotechnical baseline tunneling report from Design-Builder to address risks with tunneling. Geotechnical risk considerations for DB projects: According to the agency, a geotechnical risk factor associated with DB delivery is the liberal interpretation of geotechnical data where design-builders may take risk with the strengths and reactions of the underground materials in order to save expenses. Highly variable geotechnical conditions make a project not be a good DB candidate. Case Study 9: Cleveland Innerbelt CCG1 (I90WB Bridge) – Cleveland, Ohio This project was the second of two selected as case studies to illustrate the way the Ohio DOT manages large DB projects with regards of geotechnical risks. The project is considered to have a high geotechnical risk due to its magnitude, and there were some significant considerations such as the need to stabilize landslides, abandoned foundations, deep layer of poor quality soil, and vibration impact on nearby structures. Location: Cleveland, Ohio Award Year: 2010 Contract Amount: $287,400,000 Status: Completed

B-44 Scope of work: Replacement of the I90 Bridge over Cuyahoga River Valley in downtown Cleveland. Includes associated roadway work to reconfigure the Interchanges adjacent to the bridge work. First project includes new bridge which will initially carry bi-direction I90 traffic, but in the future will carry only I90WB traffic. The project included approximately 2 miles of mainline interstate reconstruction, including a 4,000’-long viaduct over the Cuyahoga River Valley, system ramps, on/off ramps, local street grid modifications. The work includes reconstruction of 15 bridges and 17 retaining walls. Geotechnical Risks: ODOT only identified the stabilization of landslides (west slope adjacent to Cuyahoga River) as complex geotechnical activity. However, given the size of the contract, the project was considered as a complex. In addition, geotechnical risks identified were: abandoned foundations; 150' average depth of poor quality soils above bedrock, for main viaduct bridge; vibration impact on existing structures; control over foundation and wall types; and mitigation of unsuitable soils. Project Delivery Method: Due to structural issues with the 1950s lnnerbelt truss bridge, project delivery was accelerated. Additionally, this project was also the last ARRA/stimulus project sold by ODOT. Plan was to utilize this project to spend any remaining ARRA funding. Due to the accelerated time frame, design-build delivery had to be utilized. Due to the unique project scope and cost, it was felt value based design-build made sense. Due to the concerns with slope stability on the west bank of the Cuyahoga River, a decision was made to design a slope stabilization approach to this region and include full construction plans for this slope stabilization as part of the design-build project. Contractual Provisions: Differing Site Conditions (DSC) clause:

B-45 “104.02.B Differing Site Conditions. Notify the Engineer as specified in C&MS 104.05 upon discovery of any of the following conditions: 1) Subsurface or latent physical conditions at the site differing materially from those indicated in the Contract Documents and are not discoverable from an investigation and analysis of the site by the DBT meeting the standard of care for such an investigation and analysis. 2) Unknown physical conditions of an unusual nature differing materially from those ordinarily encountered and generally recognized as inherent in the Work provided for in the Contract Documents, are encountered at the site. Provide required notification before disturbing any differing site condition. Irrespective of the previous paragraph, the following will not be considered Differing Site Conditions for purposes of this section: 1) Work involving regulated materials (e.g., asbestos) of the buildings to which the DBT did not have access to during development of their Technical Proposal. This work will be compensated as per the Project Scope, Section 5. 2) Work involving utility relocations or utility coordination. This work will be addressed in accordance with the Project Scope, Section 6. Upon notification from the DBT, the Engineer will investigate potential differing site conditions. The Engineer will determine if differing site conditions have been encountered and notify the DBT of the Department's determination. If the Department determines that conditions materially differ and cause an increase or decrease in the cost or time required for the performance of any Work under the Contract, the Department will make an adjustment and modify the Contract as specified in CMS 109.05 and as follows:

B-46 1) The first $500, 000 of direct costs and associated impact will be the responsibility of the DBT. 2) All costs which exceed the amount identified in item #1 above will be computed and paid to the DBT without any markup. Department acknowledged differing site condition Work is excusable, compensable, as defined by CMS 108. 06 D except as noted in this section.” Agency approach to manage the geotechnical risk: the agency conducted a robust subsurface exploration program in advance of the procurement, prescribed the west bank slope stabilization with sealed construction plans in the contract documents, and provided scope language requiring deep foundations to bedrock for the main viaduct bridge, and drilled shaft foundations for main viaduct substructures located within the Cuyahoga River west bank zone. A $500,000 differing site conditions threshold was included in the contract. Geotechnical risk considerations for DB projects: Concerns of ODOT about geotechnical risk are the less oversight over interpretation of data can be a risk when designers and/or contractors are motivated by schedule and budgets, the risk that the DB team provides an inadequate body of supporting geotechnical exploration and design information that weakens its position in future dispute resolution or litigation, and lack of sufficient geotechnical data upon which proposers base a responsive bid. ODOT considers that projects with geotechnical risks that are not quantifiable in simple probabilistic terms and cannot economically be solved by DB procurement should be candidate to DBB delivery because it would be more effective and efficient.

B-47 Case Study 10: Port Access Road – Charleston County, South Carolina This project was selected as a study due to the high geotechnical risk involved. The project is located in a highly seismic location and the subsurface conditions consisted of liquefiable soils, soft compressive clays, high variability due to dipping stratum, and the potential for environmental contamination. The site is considered to have higher seismic acceleration than California. Location: Charleston County, South Carolina Award Year: 2016 Contract Amount: $220,700,475 Status: Ongoing Scope of work: “The Port Access Road is a new roadway and structure Project to provide direct access between the proposed marine container terminal location on the former Navy Base and I-26 while maintaining adequate service for local, commuter, and commercial traffic. Included in the Project’s purpose is the intent to safely integrate container terminal traffic with existing traffic; support local and regional planning policies and strategies; and minimizing adverse impacts on communities and the environment. The Project consists of the construction of a new fully directional interchange on I-26, a Bainbridge Connector Road, the extension of Stromboli Avenue and associated roadway improvements to surface streets to serve the proposed Naval Base Terminal (NBT) in Charleston County, South Carolina.” Geotechnical Risks: The risk was perceived to be very significant, therefore, extensive geotechnical and environmental testing was completed prior to advertising the project to assess the potential risk. The project is located in a highly seismic area. Underground conditions consist of soil potential for liquefaction, soft compressive clays, variable conditions and dipping stratum, and the potential for environmental contamination.

B-48 Project Delivery Method: The following criteria determines the project delivery method: size/estimated dollar value of the project, challenging ground conditions, environmental contamination, and potential for innovation. The agency is evaluating the use of a decision-making matrix for future projects, a Design-Build Manual is under development. Contractual Provisions: Alternative Technical Concepts: ATCs were received for this project, but none based on geotechnical considerations. No ATCs were allowed for changing the seismic criteria in this project. - Contractual clause extract: “An Alternative Technical Concept (ATC) is a confidential request by a Proposer to modify a contract requirement, specifically for that Proposer, prior to the Proposal due date. The ATC process provides an opportunity for design-build proposals to promote innovation, find the best solutions, and to maintain flexibility in the procurement process. ATC’s are evaluated for approval or denial by SCDOT within the deadline set forth in the Milestone Schedule. In order to be approved, an ATC must be deemed, in SCDOT’s sole discretion, to provide a Project that is “equal or better” on an overall basis than the Project would be without the proposed ATC. Concepts that simply delete scope, lower performance requirements, lower standards, conflict with environmental commitments, or reduce contract requirements are not acceptable as ATC’s. SCDOT reserves the right in its sole discretion to reject any ATC. No ATC shall be included in the proposal unless approved by SCDOT in writing prior to the proposal submission deadline.” Differing Site Conditions (DSC) clause:

B-49 “XIII. DIFFERING SITE CONDITIONS A. “Differing Site Conditions” are defined as concealed or latent physical conditions at the Site that (i) materially differ from the conditions reasonably assumed to exist based on the information contained in the RFP, this Agreement and its Exhibits; or (ii) are of an unusual nature, differing materially from the conditions ordinarily encountered and generally recognized as inherent in the work. For this project, geotechnical/geological conditions WILL NOT be considered as a Differing Site Condition.” Agency approach to manage the geotechnical risk: A total of about $1.2 million and more than 7000 man-hours were used for performing the geotechnical and environmental investigations in this project, around a third of the cost was due to deep boring for seismic consideration. There is interpretation of the data, though it doesn’t specifically reference DSC clause and is provided for information only. Interpretation of the data is used in part in developing the RFP to determine liquefaction potential and preliminary stability analysis. Some additional actions are detailed as follows: - More information was made available to the proposers, including deep boring. As much drilling as the agency could do was performed, up to approximately 70% of what would have been done for a DBB. Regular projects are around 20-30% or enough to meet NEPA test. - The alignment was narrowed down for this project, so the contractor did not have too much freedom to change it. - Seismic parameters where provided. Liquefaction or loss of shear capacity and slope stability.

B-50 - An attempt to reduce overall risk was made by conducting relatively extensive geotechnical and environmental testing prior to issuing an RFP. A specified dollar allowance was included in the RFP Agreement for testing and handling of hazardous materials (environmental contamination). - Differing Site Conditions rights due to geotechnical/geological issues were eliminated from the contract. The contract also included compensation for the encountering of hazardous materials on the site: “G. Compensation for SUBSURFACE Hazardous Material: … 5. Contractor shall be responsible for the first $2,000,000 of Hazardous Materials Costs and shall include $2,000,000 for Hazardous Materials Cost as a part of its “Total Cost to Complete” in its Cost Proposal Bid Form. The $2,000,000 Hazardous Materials Costs shall be included in the Schedule of Values as a separate item. SCDOT will track Hazardous Materials Costs per the SCDOT Standard Specifications. 6. SCDOT shall compensate Contractor for 100% of the total chargeable Preexisting Subsurface Hazardous Materials costs that exceed $2,000,000. 7. Contractor shall take all reasonable steps to minimize generation of any such Hazardous Waste. 8. Time Extensions: Contractor shall not be entitled to an extension of Contract Time with regard to any work or activities connected to or associated with subsurface Hazardous Materials…” Geotechnical risk considerations for DB projects: Unexpected subsurface conditions seems to be the biggest risk factor in DB projects; particularly when conditions differ from those provided

B-51 in GBRs or Data Reports. The agency believes that projects where there is significant risk of long- term settlement of embankments and/or structures, or any risks for which the agency needs to retain control are geotechnical factors that SCDOT would advise against the use of DB delivery method. Case Study 11: I-40 Landslide Project – Haywood, North Carolina This project was selected for inclusion to demonstrate how the North Carolina DOT (NCDOT) managed the geotechnical risks in a time-sensitive and complex project. This project consisted of an emergency repair on I-40 due to several landslides in the area, the Project Delivery Method used was Design-Bid-Build with a ‘nested’ Design-Build component. NCDOT does not allow change orders due to Differing Site Conditions. Due to the emergency nature of the project, a geotechnical designer was selected by NCDOT for the ‘nested’ DB component and the General Contractor had to work with them. Location: Haywood, North Carolina Award Year: 2004 Contract Amount: $10,584,740.53 Status: Completed Scope of work: The 2004 hurricane season wreaked havoc in western North Carolina from four different storm events with immense rainfall. These rains caused a massive amount of damage to the communities and transportation facilities in western North Carolina. The Pigeon River, swollen with runoff from Hurricanes Jeanne and Ivan and a flood release from the Walters Dam scoured away the toe of several embankment slopes supporting Interstate 40 near the North Carolina-Tennessee border. On September 17, 2004, several landslides occurred between Mile

B-52 Markers 1 and 4. Portions of eastbound I-40 fell into the river. I-40 was closed in both directions and traffic was rerouted. The NCDOT was faced with the challenge of re-opening all lanes of traffic on I-40 to the traveling public as soon as possible. Numerous units from the Design Branch and the Division Construction staff of the NCDOT had to work together within a tight schedule in order to accomplish this task. Geotechnical Risks: NCDOT realized that the required tie-backs for the retaining wall were going to have to be long, a risk was identified for the case that the required length ends up being longer than expected due to the site conditions. In addition, the potential was identified for finding underground boulders on the site, which would impact the project execution. Project Delivery Method: NCDOT calls the delivery method used for this project a ‘Nested Design-Build’. The project has Design-Bid-Build components (scour protection system) as well as Design-Build (Tie-back retention wall). The delivery method was selected to accelerate the project due to the emergency situation. NCDOT selected the geotechnical design firm to work with the General Contractor for the ‘nested’ DB component. “The successful prime contractor subsequently shall enter into a subcontract with the successful geotechnical subcontractor chosen by the Department.” Contractual Provisions: Alternative Technical Concepts: No ATCs were allowed for this project. Differing Site Conditions (DSC) clause: NCDOT does not allow change orders due to Differing Site Conditions, a state law was passed to eliminate the contractual clause. - Contractual clause extracts: NCDOT’s Standard Specifications Manual states the following:

B-53 “102-7 SUBSURFACE INVESTIGATION REPORT If a subsurface investigation report is available on a project, a copy may be obtained by the plan holders upon request. The subsurface report and the subsurface investigation on which it is based was made for study, planning and design and not for construction or pay purposes. The various field boring logs, rock cores and soil test data available may be reviewed or inspected in Raleigh at the office of the Geotechnical Engineering Unit. Neither the subsurface investigation report nor the field boring logs, rock cores, or soil test data is part of the contract. General soil and rock strata descriptions and indicated boundaries are based on a geotechnical interpretation of all available subsurface data and may not necessarily reflect the actual subsurface conditions between borings or between sampled strata within the borehole. The laboratory sample data and the in-place test data can be relied on only to the degree of reliability inherent in the standard test method. The observed water levels or soil moisture conditions indicated in the subsurface investigations are as recorded at the time of the investigation. These water levels or soil moisture conditions may vary considerably with time according to climatic conditions including temperature, precipitation and wind, as well as other non-climatic factors. The bidder or contractor is cautioned that details shown in the subsurface investigation report are preliminary only; the final design details may be different. For bidding and construction purposes, refer to the contract for final design information on this project. The Department does not warrant or guarantee the sufficiency or accuracy of the investigation made, nor the interpretations made or opinions of the Department as to

B-54 the type of materials and conditions that may be encountered. The bidder or contractor is cautioned to make independent subsurface investigations, as he deems necessary, to satisfy himself as to conditions to be encountered on this project. The Contractor shall have no claim for additional compensation or for an extension of time for any reason resulting from the actual conditions encountered at the site differing from those indicated in the subsurface investigation.” Agency approach to manage the geotechnical risk: NCDOT provides as much raw geotechnical data (no interpretation) as possible in their contracts. In this project, due to the emergency nature, four different geotechnical firms were contracted to perform borings and collect data at each landslide location. A total of 35 borings were performed in a 3-week timeframe, which was the time spent for letting and awarding the contract. The geotechnical studies in this project represented around 5% of the project total amount, when the typical value for NCDOT’s DB projects is around 1%. The proposers are typically able to request additional borings to be performed by NCDOT during the letting process. The results of these 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. Geotechnical risk considerations for DB projects: The agency considers that giving as much geotechnical information as they can might reduce the probability of contractors increasing their prices. Moreover, geotechnical risks such as highly compressive or too soft soils and the presence of special structures such as historic buildings could cause the agency to advice against delivering a DB project.

Next: Appendix C: Details of Geotechnical Risk Management Tools »
Managing Geotechnical Risks in Design–Build Projects Get This Book
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TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 247: Managing Geotechnical Risks in Design–Build Projects documents the research effort to produce NCHRP Research Report 884: Guidelines for Managing Geotechnical Risks in Design–Build Projects.

NCHRP Research Report 884 provides guidelines for the implementation of geotechnical risk management measures for design–build project delivery. The guidelines provide five strategies for aligning a transportation agency and its design–builder’s perception of geotechnical risk as well as 25 geotechnical risk management tools that can be used to implement the strategies on typical design–build projects. This report helps to identify and evaluate opportunities to measurably reduce the levels of geotechnical uncertainty before contract award, as well as equitably distribute the remaining risk between the parties during contract execution so that there is a positive impact on project cost and schedule.

In addition to the guidelines, the report is accompanied by an excel spreadsheet called the Geotechnical Risk Management Plan Template.

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