Managing Geotechnical Risks in Design–Build Projects (2018)

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NCHRP Web-Only Document 247: Managing Geotechnical Risks in Design-Build Projects Douglas D. Gransberg IOWA STATE UNIVERSITY Ames, IA Michael Loulakis CAPITAL PROJECT STRATEGIES, LLC Reston, VA Ali Touran NORTHEASTERN UNIVERSITY Boston, MA Ghada Gad CALIFORNIA STATE POLYTECHNIC UNIVERSITY Pomona, CA Kevin McLain MISSOURI DOT Jefferson City, MO Shannon Sweitzer S&ME Raleigh, NC Dominique Pittenger ARBOR SERVICES, LLC Norman, OK Ivan Castro Nova Ricardo Tapia Pereira Milagros Pinto-Nunez IOWA STATE UNIVERSITY Ames, IA Contractor’s Final Report for NCHRP Project 24-44 Submitted February 2018 ACKNOWEDGMENT This work was sponsored by the American Association of State Highway and Transportation Officials (AASHTO), in cooperation with the Federal Highway Administration, and was conducted in the National Cooperative Highway Research Program (NCHRP), which is administered by the Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FRA, FTA, Office of the Assistant Secretary for Research and Technology, PHMSA, or TDC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. DISCLAIMER The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research. They are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors. The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.

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iii Contents Summary ......................................................................................................................................... 1  Chapter 1:  Background ............................................................................................................... 3  1.1.  The Research Problem ..................................................................................................... 3  1.2.  Background ...................................................................................................................... 7  1.3.  Choosing Alternative Project Delivery ............................................................................ 8  1.4.  Research Problem Statement .......................................................................................... 11  1.5.  Research Objectives ....................................................................................................... 12  Chapter 2:  Research Approach ................................................................................................. 16  2.1.  Research Framework ...................................................................................................... 16  2.1.1.  Phase 1: Benchmark the State-of-the-Practice in Geotechnical Risk ..................... 18  2.1.2.  Phase 2: Geotechnical Risk Assessment ................................................................. 28  2.2.  Phase II Work Plan Task Completion ............................................................................ 35  2.2.2.  Risk Quantification Approach ................................................................................ 36  Chapter 3:  Findings and Applications ...................................................................................... 49  3.1.  Introduction .................................................................................................................... 49  3.2.  Summary and Analysis of the Literature Review and Content Analysis. ...................... 49  3.2.1.  Geotechnical Risk Literature .................................................................................. 49 

iv 3.2.2.  Design-Build Literature .......................................................................................... 54  3.2.3.  Findings from the Literature ................................................................................... 55  3.2.4.  Findings from the Content Analysis ....................................................................... 56  3.3.  Summary and Analysis Surveys ..................................................................................... 65  3.3.1.  Findings from Survey of State DOTs (Survey 1) ................................................... 65  3.3.2.  Survey of DB Geotechnical Risk Experts (Survey 2) ............................................. 96  3.4.  Summary and Analysis of Case Study Interviews ....................................................... 109  3.5.  Summary and Analysis of Legal Review ..................................................................... 111  3.6.  Application of the Findings .......................................................................................... 112  Chapter 4:  Conclusions and Suggested Research ................................................................... 117  4.1.  Benchmarks: ................................................................................................................. 117  4.2.  Perception of the Geotechnical Risk ............................................................................ 118  4.3.  Strategies for Aligning the Perceived Geotechnical Risk. ........................................... 119  4.4.  Tools for Managing Geotechnical Risks ...................................................................... 120  4.5.  Potential Solutions to Achieve an Aligned Approach to Geotechnical Risk. .............. 122  4.6.  Suggested Future Research and Implementation ......................................................... 123  References ................................................................................................................................... 125  Abbreviations and Acronyms ..................................................................................................... 130  Appendix A: State of the Practice ............................................................................................. A-1  Appendix B: Case Study Reports .............................................................................................. B-1 

v Appendix C: Details of Geotechnical Risk Management Tools ................................................ C-1  Appendix D: Final Guidelines ................................................................................................... D-1  Appendix E: Detailed Results of the Geotechnical Legal Review ............................................. E-1  Appendix F: Interview and Survey Forms.................................................................................. F-1  Table of Figures Figure 2.1 – Phase 1 Research Work Plan.................................................................................... 17  Figure 2.2 – Phase 2 Research Work Plan.................................................................................... 18  Figure 2.3 – Conceptual Research Framework for Quantitative Geotechnical Risk Analysis ..... 26  Figure 2.4 – Risk Quantification Approaches .............................................................................. 37  Figure 2.5 – The Proposed Two-step Procedure for Estimating Project Risk Score .................... 39  Figure 2.6 – Risk Register for Quantitative Risk Assessment (Adapted from VDOT Risk Management Matrix) .................................................................................................................... 44  Figure 2.7 – Partially Filled-out Risk Register with Identified Risk Factors ............................... 44  Figure 2.8 – Cost Estimate for Risk Factors .................................................................................45  Figure 2.9 – Total Cost for Geotechnical Risks (a- Probability distribution; b- Cumulative distribution) .................................................................................................................................. 45  Figure 2.10 – The Effect of Mitigation Effort .............................................................................. 46  Figure 3.1 – Differing Site Conditions Risk Liability Flow Chart (Hanna et al. 2015). .............. 51  Figure 3.2 – Color Coding for a Section of the Borinquen Dam 1E Foundation Geological Profile (Tapia et al. 2017). ........................................................................................................................ 52 

vi Figure 3.3 – Example of DB Decision Change Based on Geotechnical Risk Assessment (Tapia et al. 2017). ....................................................................................................................................... 53  Figure 3.4 – Respondent Group/Section Assignment. .................................................................. 66  Figure 3.5 – Use of Alternative Contracting Methods .................................................................. 67  Figure 3.6 – How many DB projects has your agency delivered? ................................................ 68  Figure 3.7 – How long has your agency been using DB projects delivery? ................................. 69  Figure 3.8 – How much preliminary geotechnical investigation is completed before making the decision to use DB project delivery for a given project? .............................................................. 70  Figure 3.9 – Steps Taken to Address Geotechnical Issues in the DB RFQ/RFP Where the Geotechnical Risks Are Considered Significant ........................................................................... 71  Figure 3.10 – Is a formal geotechnical risk analysis conducted on a typical project in any of the following areas? ............................................................................................................................ 72  Figure 3.11 – Within the geotechnical risk management process that is conducted by the agency or required of the design builder? ................................................................................................. 73  Figure 3.12 – Which of the following best describes the content of the risk register of geotechnical issues? ........................................................................................................................................... 74  Figure 3.13 – What types of geotechnical risks do you typically encounter on DB projects and how are they allocated? ......................................................................................................................... 75  Figure 3.14 – DOTs and Geotechnical Factors Weight in the Evaluation Plan. .......................... 76  Figure 3.15 – DOT Survey Response Results Regarding Geotechnical Content Provided RFP. 77  Figure 3.16 – RFP Additional Geotechnical Information by Design Builders. ............................ 78  Figure 3.17 – DOTs Procurement Phase Practices DB Project with Significant Geotechnical Risks ....................................................................................................................................................... 78 

vii Figure 3.18 – Average Scores of Importance of Geotechnical Areas to the Success of the Project During the Procurement Process ................................................................................................... 80  Figure 3.19 – Type of Payments in a DB Project ......................................................................... 81  Figure 3. 20 – Geotechnical Aspects of DB Contracts ................................................................. 82  Figure 3.21 – What document, if any, is used to define a differing geotechnical site condition? 84  Figure 3.22 – How do you rate the final quality of geotechnical work on DB projects compared to DBB projects? ............................................................................................................................... 86  Figure 3.23 – Please rate the following geotechnical factors for their impact on the final quality/performance of the DB project. ........................................................................................ 87  Figure 3.24 – Geotechnical Evaluation Criteria Weighting. ......................................................... 89  Figure 3.25 – Impact of Geotechnical Risk Factors ..................................................................... 90  Figure 3.26 – Geotechnical Risk Allocation ................................................................................. 91  Figure 3.27 – Formal Geotechnical Risk Analysis ....................................................................... 92  Figure 3.28 – Perception of Geotechnical Risk Impact .............................................................. 102  Figure 3.29 – Importance Index of Geotechnical Risk Factors .................................................. 104  Figure 3.30 – Geotechnical Risk Allocation in DB Contract. .................................................... 107 Figure A. 1 – Changes vs Ratio of Borehole Length to Tunnel Length (Hoek and Palmeiri 1998) ..................................................................................................................................................... A.6  Figure A. 2 – Cost Overrun vs Site Investigation Expenditures (Mott McDonald & Soil Mechanics Ltd 1994) ..................................................................................................................................... A.7  Figure A. 3 – Development of Geotechnical Investigation Program .......................................... A.8  Figure A. 4 – Use of Geotechnical Baseline in DB projects .................................................... A.12  Figure A. 5 – Sources of Error or Uncertainty in Soil Property Estimates (Baecher 1987) ..... A.14 

viii Figure A. 6 – A Risk-based Design Approach for Slope Stability (Clayton 2001) ................... A.15 Figure A. 7 – Proposed Modeling Approach for Geotechnical Risk Analysis in DB Projects.... A.16 Figure A. 8 – Risk Assessment Process .................................................................................... A.17  Figure A. 9 – Generic DB Timeline .......................................................................................... A.19 Figure B.1 – Plan View of Dallas Horseshoe Project ................................................................. B.25  Table of Tables Table 1.1 – Project Characteristics that Indicate a Given Project Is a Poor Candidate for DB Project Delivery Found in the Literature (Gransberg and Loulakis 2011)….……………………………… 12 Table 3.1 – List of Projects in Content Analysis ........................................................................... 57  Table 3.2 – Content Analysis: Scope of Information Provided Pre-bid........................................ 59  Table 3.3 – Content Analysis: Extent to Which the Geotechnical Gathering Process Is Table 3.4 – Content Analysis: Description of Project with Significant Geotechnical Issues ....... 60  Table 3.5 – Content Analysis: Information Required from Contractors in Post-award ............... 60  Table 3.6 – Content Analysis: Evaluation Criteria in Selection Process ....................................... 61  Table 3.7 – Content Analysis: Weight of Geotechnical Factors in Proposal Evaluation .............. 61  Table 3.8 – Content Analysis: Design and Performance Criteria to be Submitted in Proposal..... 62  Table 3.9 – Content Analysis: Use of Performance Verification and Measurement Methods ...... 62  Table 3.10 – Content Analysis: Differing Site Conditions Clause ................................................. 63  Table 3.11 – Content Analysis: Warranties used for Geotechnical Performance .......................... 63  Table 3.12 – Content Analysis: Provisions for Alternative Technical Concepts (ATCs) .............. 64  Table 3.13 – Content Analysis: Methods for Mitigating High-risk Geotechnical Conditions ....... 64  Table 3.14 – Survey Respondent and Categorization Based on Experience in DB Projects .......... 88  Interactive .…..……………………………………………………………………...................... 59

ix Table 3.16 – Frequency of Geotechnical Factor Risk in DB Projects .......................................... 98  Table 3.17 – Impact of Geotechnical Factor Risk in DB Projects ................................................ 99  Table 3.18 – Importance Index of Geotechnical Factor Risk in DB Projects ............................. 101  Table 3.19 – List of Geotechnical Risk Factors .......................................................................... 103  Table 3.20 – Geotechnical Risk Factors that Make Not to Pursue/Recommend a DB Project .. 106  Table 3.21 – Ten Most Encountered Geotechnical Risk Factors ................................................ 107  Table 3.22 – Case Studies and Interviews .................................................................................. 110  Table 3.23 – Summary of Case Studies–Geotechnical Risk Mitigation Actions. ...................... 111  Table 3.24 – Implement Early Contractor Design Involvement ................................................. 114  Table 3.25 – Involve Third Party Stakeholders as Early as Practical ......................................... 115  Table 3.26 – Raise the Visibility of Geotechnical Issues ........................................................... 115  Table 3.27 – Enhanced DB Geotechnical Contract Mechanisms ............................................... 116  Table 3.28 – Life Cycle-based Design and Construction Decision-making .............................. 116 Table 4.1 – List of Tools …..……………………………………………………………………125 Table 3. 15 – Summary of Chi-Square Test Results–Experienced vs Non-experienced ............. 90 

x Author Acknowledgments The research reported herein was performed under NCHRP Project 24-44 by the Institute for Transportation Research (InTrans) at Iowa State University. Additionally, Northeastern University (NU) and California Polytechnic University at Pomona (CPP) provided Co-Principal Investigators (Co-PI). InTrans was the prime contractor for the study. The authors would like to acknowledge the contribution of the Missouri Department of Transportation furnished by making Dr. Kevin McLain, PE, its Director of Geotechnical Engineering, available to the project at no cost. Michael Loulakis, JD Capital Project Strategies, LLC, Reston, VA, Shannon Sweitzer, PE of SM&E, Inc., Raleigh, NC, and Dr. Dominique Pittenger of Arbor Services, Inc. Norman, OK all served as Co-PIs. Dr. Douglas Gransberg, PE of ISU led the team as PI with Drs. Ali Touran, PE (NU) and Ghada Gad (CPP) were Co-PIs. The ISU Graduate Research Assistants on the project were Ivan Castro Nova now of Manatts Construction, Des Moines, Iowa and Dr. Ricardo Tapia Pieria, now of the Panama Canal Authority, and Dr. Milagros Pinto Nunez of the Technical University of Panama.

xi Abstract This research developed a set of geotechnical risk management guidelines for design-build (DB) transportation projects. Geotechnical uncertainty is always high in DB projects where foundation conditions are unknown at the time the contract is awarded and where the design-builder is expected to conduct the subsurface investigations necessary to complete the design after establishing the project contract price. This issue is exacerbated by the fact that public agencies typically select DB project delivery when they want to accelerate project delivery. The guidelines are based primarily on the data gathered by a survey of state DOTs, a second survey of both DOT and industry respondents with experience in DB geotechnical risk mitigation experience, and 20 case study projects. The major finding was a significant disparity in the perceptions of geotechnical risk of DOT engineers versus the industry experts. This led to the conclusion that DB geotechnical risk management strategies must necessarily permit an opportunity to align perceptions of risk and, if possible, mutually apportion the project’s geotechnical risk profile. The use of progressive DB, scope validation periods, and multiple notices to proceed are recommended as contractual tools to achieve this purpose.