National Academies Press: OpenBook

Guidelines for Managing Geotechnical Risks in Design–Build Projects (2018)

Chapter: Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template

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Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
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Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
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Page 49
Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
×
Page 49
Page 50
Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
×
Page 50
Page 51
Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
×
Page 51
Page 52
Suggested Citation:"Chapter 7 - Design Build Geotechnical Risk Management Planning Workshop Template." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Managing Geotechnical Risks in Design–Build Projects. Washington, DC: The National Academies Press. doi: 10.17226/25262.
×
Page 52

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47 This chapter provides guidance on developing and delivering the required series of DB geo- technical risk management planning workshops. Before embarking on this exercise, an initial meeting is conducted to determine whether DB delivery is appropriate and, if it is, whether the specific project’s geotechnical risk profile is high enough to justify dealing with geotechnical risk differently from the remainder of the risks in the project’s risk register. Figure 7.1 illustrates the flowchart for the initial scoping of geotechnical risk. The output from that process validates the DB delivery decision and prepares an outline plan for addressing geotechnical risk in the plan- ning, preliminary engineering, and procurement phases before DB contract award and the design and construction phases after DB contract award. The basis of the DB geotechnical risk management plan is the development of a geotechnical risk register. This document can be either a stand-alone document devoted specifically to geo- technical risk or an extract from a larger DB project risk register that covers all subsurface risks, including the geotechnical and geophysical ones. As discussed in Chapter 6, the geotechnical risk register is developed during DB project development, updated on the basis of preliminary geo- technical engineering investigation, if applicable, and jointly reviewed and revised after award with the winning design–builder’s geotechnical/construction staff, and updated as new geo- technical risks are encountered during design phase investigations and construction, and also as geotechnical risks are retired. Figure 7.2 provides a flowchart for the continuous management of geotechnical risk and the use of workshops to evaluate, mitigate, and retire geotechnical risks throughout the project development and delivery life cycle. The effort intensifies once the DB contract is awarded and the initial collaboration between the owner and the design–builder commences. Figure 7.2 also shows the points at which spreadsheet templates contained in Appendix C are put to use. 7.1 Design–Build Project Geotechnical Risk Management Plan Table 7.1 provides the outline for a DB project geotechnical risk management plan. The Table 7.1 process is reasonably self-explanatory and proceeds according to the following steps. 1. After the initial geotechnical risk scoping has been completed (Figure 7.1), the project team will then determine which of the five risk mitigation/management strategies are most appro- priate for the project at hand. The team can choose as many as seem prudent for the project on the basis of its initial risk profile. 2. In the next step, the risks identified in the initial risk scoping output are assigned to each strategy as appropriate. Table 2.4 furnishes a ranked checklist for ensuring that the 29 most common risks found in the research are addressed along with the relative impact of each one. C H A P T E R 7 Design–Build Geotechnical Risk Management Planning Workshop Template

48 Guidelines for Managing Geotechnical Risks in Design–Build Projects Yes Assign highly qualified owner geotech personnel to project RFQ: Highly qualified DB’er geotech personnel RFP: − Confidential 1-on-1 meetings − Preapproved ATCs − DB’er additionalsite investigation − Risk-sharing DSC clause − Specify performance measures Mandate high confidence geotech design solutions Assure geotech design quality - Increased agency involvement in geotech design QA Expedite geotech design − Maximize over-the-shoulder design review − Single geotech design review − Early release of geotech design packages Assure geotech construction quality − Increased agency involvement in construction QA − Use of instrumentation to verify geotech performance − Specific geotech verification & acceptance testing plan No Need Early Geotech Design Release? Yes Routine Pre-Award Geotechnical Uncertainty? High Procurement Phase Plan Design Phase Plan Construction Phase Plan Geotechnical Risk Mitigation Approach Treat Geotech Design Same as Remainder of DB Project Select DB Select DBB No Need to Accelerate Project Delivery? Project Geotechnical Requirements Figure 7.1. Initial geotechnical risk scoping flowchart. Procurement phase plan, design phase plan, and construction phase plan bullet items move to the flowchart in Figure 7.2.

Design–Build Geotechnical Risk Management Planning Workshop Template 49 Figure 7.2. Design–build geotechnical risk workshops flowchart.

50 Guidelines for Managing Geotechnical Risks in Design–Build Projects 3. The next step is to correlate the risks to the DB project’s schedule by completing the expected risk exposure/retirement dates to the current schedule for project development. Those dates may not be known at the initial iteration of the process and should be added as project devel- opment progresses and project milestones are added to the schedule. 4. Determining which risks will be addressed before contract award and after contract award is the aim of the next step. There is no rule for when a specific risk is addressed, but the project team must keep in mind that most risks are realized during construction and make plans to ensure all identified risks are covered in the plan. 5. In this step, Tables 5.2 through 5.6 provide guidance for selecting tools and the phase in which they are most effective. The team will then select the specific tools with which they intend to manage or mitigate each risk in the plan and assign them in the appropriate phases. 6. The completed document should be scheduled for a regular periodic review and update as the DB project proceeds from planning to preliminary engineering into procurement and ultimately contract award to completion. 7.2 Example Design–Build Project Geotechnical Risk Management Plan The above process will be illustrated by example for one of the case study projects collected during the research. The below example has been abbreviated for illustration purposes; the actual process was much more detailed. Additionally, the facts of the case study have been retroactively applied to Geotechnical Risk Management Plan Project Phase Strategy Risk # Geotechnical/ Subsurface Risk Risk Exposure Date Exposure Passed Date Expected Retired Date Pre- advertising Procurement Pre- construction Construction Geotechnical Risk Mitigation Tool Assigned to Risk 1 Early Contractor Involve- ment 2 Early 3rd Party Involve- ment 3 Increase Visibility of Geo- technical Issues 4 Enhanced Contract Mechanisms 5 Life Cycle Decision Making Table 7.1. Outline for a DB geotechnical risk management plan.

Design–Build Geotechnical Risk Management Planning Workshop Template 51 the model. Last, accurate risk exposure date data were not available. Therefore, Table 7.2 lists the acronym TBD (to be determined) in some cells. Not knowing the expected exposure dates will often be the case in early iterations of the process and these may not firm up until the DB con- tract is awarded. Nevertheless, the dialogue stimulated among the project delivery team members about these dates will add value to the overall risk analysis process. The project is the Trunk Highway 61 Hastings Bridge Replacement DB Project completed by the Minnesota DOT. The project involved replacing an existing bridge over the Mississippi River at Hastings, Minnesota, with the difficult foundation conditions that had to be dealt with on the north approach to this bridge. The project involved replacing an existing bridge whose northern abutment had serious settlement issues throughout its 30-year service life. In fact, the abutment had been jacked back up into alignment three times. During the proposal preparation period, the Minnesota DOT successfully employed the use of preapproved elements that resulted from the analysis of ATCs proposed and discussed during confidential one-on-one meetings that resulted in the winning design–builder proposing a column-supported embankment to address the extremely poor north approach subsurface conditions. After the decision to select DB project delivery, the Minnesota DOT chose to use three of the strategies and the following corresponding tools: • Risk Mitigation Strategy 1 (see Table 5.2) – Tool 9: Request of geotechnical and/or utilities ATCs – Tool 17: Multiple NTPs – Tool 23: Assign design–builder responsibility for utility coordination • Risk Mitigation Strategy 3 (see Table 5.4) – Tool 3: Geotechnical conditions database – Tool 5: Prescriptive geotechnical design – Tool 6: Performance specifications for post-construction performance – Tool 7: Include DSC clause – Tool 14: Weight geotechnical evaluation criteria Example Project: Hastings Bridge Replacement DB Project Geotechnical Risk Management Plan Project Phase Strategy Risk # Geotechnical/ Subsurface Risk Risk Exposure Date Exposure Passed Date Expected Retired Date Pre- advertising Procurement Pre- construction Construction Geotechnical Risk Mitigation Tool Assigned to Risk 1 Early Contractor Involve- ment 8 Underground manmade debris TBD TBD TBD 17 23 11 Settlement of bridge approaches TBD TBD TBD 9 17 20 Sensitiveness of public considerations (parks, historic buildings, etc.) TBD TBD TBD 9 3 Increase Visibility of Geo- technical Issues 24 Soft clays, organic silts, or peat TBD TBD TBD 3 7, 14 5, 6 6 25 Highly compressive soils TBD TBD TBD 7, 14 5 5 Life Cycle Decision Making 23 Settlement in general TBD TBD TBD 15 24 26 Scour of bridge piers TBD TBD TBD 25 Table 7.2. Example of a geotechnical risk management plan.

52 Guidelines for Managing Geotechnical Risks in Design–Build Projects • Risk Mitigation Strategy 5 (see Table 5.6) – Tool 15: Include life cycle criteria in best value award scheme – Tool 24: Validate proposed life cycle elements during design – Tool 25: Encourage life cycle-related value engineering proposals from subcontractors The specifics of each tool for this project are not important to demonstrate the use of the template. However, the essential highlights of each are as follows: • Tool 3: The complete database of geotechnical conditions on the project site was furnished along with the RFP. • Tool 5: Minnesota DOT prescribed supplemental investigations to be conducted by the design–builder after award in areas of known geotechnical uncertainty. • Tool 6: Performance criteria for subsidence was prescribed and, as a result, the winning proposal submitted an ATC that proposed the installation of instrumentation to permit the Minnesota DOT to accurately monitor settlement of the north approach over the 3-year warranty period. • Tool 7: A standard DSC clause was included in the contract and was used to settle issues dealing with the impact of flooding that occurred during construction. • Tool 9: Minnesota DOT not only requested ATCs but also required preapproved elements for several features of work, including a plan to minimize vibrations that might damage several historic riverfront buildings. • Tool 14: Geotechnical aspects of the proposals were assigned 8% of the weight for the entire project. Past research found that anything over 5% for a single evaluation category would be considered heavy weighting. • Tool 15: The proposed plans to manage settlement, vibrations during construction, and sup- plemental investigations were all evaluated and carried weight in the best value award scheme. • Tool 17: Two NTPs were prescribed in the RFP with the first one including the geotechnical work necessary to support the foundation design. • Tool 23: The winning DB team submitted an ATC that reduced the number of anticipated utility service outages and expedited restoration of service during the bridge span placements. • Tool 24: The evaluation panel checked the life cycle-oriented portions of the geotechnical portion of the proposal. • Tool 25: The proposers were encouraged to submit options for dealing with bridge pier scour. To summarize, the above procedure will use the various templates found in Appendix B as mechanisms to populate Table 7.1. The finished plan can be merged with the project’s overall risk management plan with confidence that geotechnical risk has been provided the appropriate amount of resources based on the DB project’s risk profile.

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TRB's National Cooperative Highway Research Program (NCHRP) Research Report 884: Guidelines for Managing Geotechnical Risks in Design–Build Projects 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. NCHRP Web-Only Document 247: Managing Geotechnical Risks in Design–Build Projects documents the research effort to produce NCHRP Research Report 884.

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