NCHRP Synthesis 428: Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions revealed that one-dimensional (1-D) equivalent-linear analysis is the de facto standard for state DOT highway facilities at those locations where site-specific ground response analyses are conducted in accordance with provisions in the AASHTO LRFD Bridge Design Specifications (2014) and the AASHTO Design Guidelines for Seismic Bridge Design (2011). However, users have concerns about the applicability of equivalent-linear analyses for the cases for which site-specific response analyses are most useful (i.e., soft soil sites, liquefiable sites, and sites subjected to very strong shaking). While nonlinear 1-D site response analyses are beginning to be used in practice to address these concerns, considerable uncertainty exists with respect to the appropriate manner in which to employ and interpret such analyses. To assist bridge and foundation designers, guidance on the use and selection of 1-D nonlinear software with pore water pressure generation is needed for the effective and economical seismic design of all types of highway structures.
The objective of this research is to provide guidance on the use and selection of analytical methods for 1-D nonlinear seismic site response analysis with pore water pressures generation to quantify the effects of site-specific conditions on earthquake ground response.
At a minimum, the guidance should consider the following: (1) input parameters required for the analyses (e.g., site characterizations, seismic loading); (2) limitation, selection, and validation of analytical methods; (3) the process of model setup; and (4) how to use the results of the analytical methods.
Accomplishment of the project objective will require at least the following tasks.
Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.
Task 1. Conduct a literature review of relevant domestic and international studies for analytical methods for one-dimensional nonlinear seismic site response analysis with pore water pressures generation. The review should include research conducted through the NCHRP; Strategic Highway Research Program 2 (SHRP 2); FHWA; and other relevant national, international, and state departments. The review shall include the identification and collection of available field and laboratory data to achieve the research objective.
Task 2. Synthesize results of Task 1 to identify the knowledge gaps and uncertainties related to the analytical methods for I-D nonlinear seismic site response analysis with pore water pressures generation. These gaps should be addressed in the final product and in the recommended future research as budget permits.
Task 3. Propose analytical and testing programs, to be executed in Phases II and III, to achieve the project objective. The analytical program shall consider at a minimum: different site characterizations, seismic loading, and soil constitutive models (e.g., the effect of soil dilation and pore pressure dissipation); and comparison of equivalent-linear and total stress nonlinear analyses to effective stress nonlinear analyses. At least four commercial software packages shall be used in the analytical modeling and validation.
Task 4. Prepare Interim Report No. 1 that documents the results of Tasks 1 through 3 and provides an updated work plan for the remainder of the project. This report is due no later than 4 months after the contract award. The updated work plan must describe the process and rationale for the work proposed for Phases II through IV.
Note: Following a 1-month review of Interim Report No. 1 by the NCHRP, the research team will be required to meet with the project panel to discuss the interim report. Work on Phases II through IV of the project will not begin until authorized by the NCHRP. Phase I shall be limited to $40,000.
PHASE II—Analytical Program
Task 5. Execute the analytical program according to the approved Interim Report No.1.
Task 6. Finalize the testing program work plan and provide a matrix of the testing specimens and parameters. The testing specimens shall consider the scale effect and testing configurations on the applicability of the results. Describe how the testing results will be utilized to achieve the research objective. The testing program may include field exploration [e.g., cone penetrometer test (CPT), and sounding, cyclic lab testing].
Task 7. Prepare an annotated table of contents for the proposed guidance, to be developed in Phase IV. Propose case studies to demonstrate the application of proposed guidance.
Task 8. Prepare Interim Report No. 2 that documents the results of Tasks 5 through 7 and provides an updated work plan for the remainder of the project. This report is due no later than 9 months after approval of Phase I. The updated plan must describe the work proposed for Phases III and IV.
Note: Following a 1-month review of Interim Report No. 2 by the NCHRP, the research team will be required to meet with the project panel to discuss the interim report. Work on Phases III and IV of the project will not begin until authorized by the NCHRP. Phase II shall be limited to $100,000.
PHASE III—Testing Program and Validation
Task 9. Execute the testing program according to the approved Interim Report No.2.
Task 10. Finalize the analytical program based on the testing program and observed data from the field array. Conduct sensitivity analyses as needed to achieve the research objective.
Task 11. Based on the analytical and testing program, summarize the pros and cons of every analytical method including when and how to use each method and update the table of contents for the proposed guidance.
Task 12. Prepare Interim Report No. 3 that documents Tasks 9 through 11 and provides an updated work plan for the remainder of the project. This report must be submitted no later than 15 months after Phase II approval.
Note: Following a 1-month review of Interim Report No. 3 by the NCHRP, the research team will be required to meet with the project panel to discuss the interim report. Work on Phases IV of the project will not begin until authorized by the NCHRP.
PHASE IV—Final Products
Task 13. Develop the draft guidance and case studies according to the approved Interim Report No. 3. The draft guidance is due no later than 3 months after approval of Phase III.
Task 14. Prepare final deliverables including: (1) the revised guidance that reflects consideration of the panel’s review comments; (2) a final report that documents the entire research effort; and (3) a stand-alone technical memorandum titled “Implementation of Research Findings and Products.” See Special Note D for additional information.
Note: Phases III and IV shall be limited to a total of $500,000. Following receipt of the draft final report, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the revised final report.
A. During the research, the research team should anticipate making presentations to appropriate technical committees at two annual meetings of the AASHTO Highway Subcommittee on Bridges and Structures.
B. To ensure that data produced under this project are accessible, a data archiving and sharing plan shall be prepared by the agency performing the research. The plan must be submitted with Task 4 and shall include a description of expected activities, schedules, limitations, milestones, and required resources. Researchers should describe briefly the expected schedule for data production and archiving in the NCHRP permanent repository, the format of the final dataset, the documentation to be provided, and whether or not any analytic tools and/or results also will be provided. The plan must include a description of actions planned to ensure quality. Moreover, the plan must specify the resources required to archive and distribute the data expected to be obtained in the course of performing the research. Public release of data will not occur before full review and approval by NCHRP.
The data archiving and sharing plan must include the following sections:
· Background and significance;
· Expected data formats;
· Description of data archiving and quality assurance plan;
· Description of data sharing plan;
· Schedule for data archiving and public release of data;
· Milestones for the implementation of the plan; and
· Resources and budget.
C. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the brochure, "Information and Instructions for Preparing Proposals" (http://onlinepubs.trb.org/onlinepubs/crp/docs/ProposalPrep.pdf). Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower-tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower-tier subaward and subcontract in excess of $25,000.
D. The NCHRP is a practical, applied research program that produces implementable products addressing problems faced by transportation practitioners and managers. The benefits of NCHRP research are realized only when the results are implemented in state DOTs and other agencies. Implementation of the research product must be considered throughout the process, from problem statement development to research contract and beyond completion of the research. Item 4(c), "Anticipated Research Results," must include the following: (a) the "product" expected from the research, (b) the audience or "market" for this product, (c) a realistic assessment of impediments to successful implementation, and (d) the institutions and individuals who might take leadership in deploying the research product. The project panel will develop and maintain an implementation plan throughout the life of the project. The research team will be expected to provide input to an implementation team consisting of panel members, AASHTO committee members, the NCHRP Implementation Coordinator, and others in order to meet the goals of NCHRP Active Implementation: Moving Research into Practice, available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP_ActiveImplementation.pdf.
E. Item 5 in the proposal, "Qualifications of the Research Team," must include a section labeled "Disclosure." Information relevant to the NCHRP's need to ensure objectivity and to be aware of possible sources of significant financial or organizational conflict of interest in conducting the research must be presented in this section of the proposal. For example, under certain conditions, ownership of the proposing agency, other organizational relationships, or proprietary rights and interests could be perceived as jeopardizing an objective approach to the research effort, and proposers are asked to disclose any such circumstances and to explain how they will be accounted for in this study. If there are no issues related to objectivity, this should be stated.
F. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively very knowledgeable in the problem area. Selection of an agency is made by the project panel considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) the proposer's plan for participation by Disadvantaged Business Enterprises--small firms owned and controlled by minorities or women; and (6) the adequacy of the facilities.
Note: The proposer's plan for participation by Disadvantaged Business Enterprises should be incorporated in Item 12 of the proposal.
G. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academies of Sciences, Engineering, and Medicine. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academies of Sciences, Engineering, and Medicine. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.