The American Association of Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications (BDS) currently contain limited design criteria for disc bearings. The BDS requirements are predominately based on NCHRP Project 10-20A, “High-Load, Multi-Rotational Bearings: Design, Materials, and Construction” initiated in 1986 and published in 1999 as NCHRP Report 432: High-Load Multi-Rotational Bridge Bearings. At the time, only one company manufactured disc bearings and testing samples of their product were limited. Since 1999, multiple companies manufacture disc bearings and industry standards have progressed.
Due to the limited research, bridge designers are reliant on disc bearing manufacturers’ unique in-house designs, which introduces uncertainties that may result in nonuniform reliability and performance. Renewed consideration of high-load multi-rotational (HMLR) disc bearings would likely result in a more thorough and robust design approach. Research is needed to update the current practice for the design, fabrication, and construction of disc bearings.
The objective of this research is to develop design procedures and acceptance testing methods and criteria for HLMR disc bearings for highway bridges. It shall be applicable to all design limit states.
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.
Note: Proposers shall include the schedule for each phase in their research plans. The sequencing of tasks and deliverables (such as technical memorandums or summary reports) shall be structured for delivery in quarterly progress report submissions. An in-person interim meeting, to be held in Washington, DC, should follow the submission of the first interim report.
Task 1. Conduct a literature review on the design and the acceptance testing of HLMR disc bearings. The review shall include published and unpublished documentation and research conducted through the NCHRP; Federal Highway Administration; other national, state, and local agencies; and international organizations.
Task 2. Synthesize the results of the literature review to identify knowledge gaps related to the research objective. These gaps should be addressed in the final product or the recommended future research, as budget permits.
Task 3. Propose the research plan to be executed in Phase II to achieve the research objective. At a minimum, the research plan shall include:
- Development of a theoretical model to describe the response of the bearings to loads as a function of geometry and material properties.
- Development of an experimental program with laboratory tests to calibrate any coefficients in the model and to verify with reasonable accuracy the behavior of bearings.
- Development of testing procedures for predicting long-term performance of the HMLR disc bearing.
- A list of design examples to demonstrate the use of the design procedures. The design examples shall cover a range of bridge geometry.
- A plan for coordinating with domestic manufacturers of HLMR disc bearings.
Task 4. Prepare Interim Report No. 1 that documents Tasks 1 through 3 and provides an updated work plan for the remainder of the research. The updated 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 meet in-person with the project panel to discuss the interim report. Work on Phase II of the project will not begin until authorized by the NCHRP.
Task 5. Execute the research plan according to the approved Interim Report No. 1.
Task 6. Develop design procedures and acceptance testing methods and criteria for HLMR disc bearings.
Task 7. Prepare Interim Report No. 2 that documents Tasks 5 and 6 and provides an updated work plan for the remainder of the research. The updated work plan must describe the process and rationale for 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 meet with the project panel to discuss the interim report. Work on Phase III of the project will not begin until authorized by the NCHRP.
PHASE III—Draft AASHTO Deliverable
Task 8. Revise the proposed design procedures and acceptance testing methods and criteria for HLMR disc bearings after consideration of the panel’s review comments.
Task 9. Develop draft language that may be considered by the AASHTO Committee on Bridges and Structures for inclusion in its next update of the AASHTO LRFD Bridge Design Specifications and AASHTO LRFD Bridge Construction Specifications (hereafter called AASHTO Deliverable).
Task 10. Prepare design examples according to the approved Interim Report No. 2.
Task 11. Prepare Interim Report No. 3 that documents Tasks 8 through 10 and provides an updated work plan for the remainder of the research. The updated work plan must describe the process and rationale for the work proposed for Phase IV.
Note: Following a 1-month review of Interim Report No. 3 by the NCHRP, the research team will meet with the project panel to discuss the interim report. Work on Phase IV of the project will not begin until authorized by the NCHRP.
PHASE IV—Final Products
Task 12. Revise the AASHTO Deliverable and design examples after consideration of the panel’s review comments.
Task 13. Submit the draft final deliverables including (1) the AASHTO Deliverable, (2) a final report that documents the entire research effort, (3) design examples, and (4) a stand-alone technical memorandum titled “Implementation of Research Findings and Products.” See Special Note J for additional information.
Note: Following receipt of the draft final deliverables, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverables. The budget for Phase IV shall be $60,000.
A. The research team should anticipate making two presentations to appropriate technical committees at AASHTO meetings.
B. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs were revised in May 2023. Please take note of the new and revised text which is highlighted in yellow.
C. Proposals must be submitted as a single PDF file with a maximum file size of 10 MB. The PDF must be formatted for standard 8 ½” X 11” paper, and the entire proposal must not exceed 60 pages (according to the page count displayed in the PDF). Proposals that do not meet these requirements will be rejected. For other requirements, refer to chapter V of the instructions.
D. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs have been modified to include a revised policy and instructions for disclosing Investigator Conflict of Interest. For more information, refer to chapter IV of the instructions. A detailed definition and examples can be found in the CRP Conflict of Interest Policy for Contractors. The proposer recommended by the project panel will be required to submit an Investigator Conflict of Interest and Disclosure Form as a prerequisite for contract negotiations.
E. Proposals will be rejected if any of the proposed research team members work for organizations represented on the project panel. The panel roster for this project can be found at https://www.mytrb.org/OnlineDirectory/Committee/Details/6929 . Proposers may not contact panel members directly; this roster is provided solely for the purpose of avoiding potential conflicts of interest.
F. Proprietary Products - If any proprietary products are to be used or tested in the project, please refer to Item 6 in the Information and Instructions for Preparing Proposals.
G. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively knowledgeable in the problem area. The project panel will recommend their first choice proposal 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) how the proposer approaches inclusion and diversity in the composition of their team and research approach, including participation by certified Disadvantaged Business Enterprises; and, if relevant, (6) the adequacy of the facilities. A recommendation by the project panel is not a guarantee of a contract. The National Academy of Sciences (NAS - the contracting authority for the National Academies of Sciences, Engineering, and Medicine) will conduct an internal due diligence review and risk assessment of the panel’s recommended proposal before contract negotiations continue.
Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 11 of the proposal.
H. 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 Academy of Sciences. 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 Academy of Sciences. 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.
I. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the Information and Instructions for Preparing Proposals. 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.
J. The required technical memorandum titled “Implementation of Research Findings and Products” should (a) provide recommendations on how to best put the research findings/products into practice; (b) identify possible institutions that might take leadership in applying the research findings/products; (c) identify issues affecting potential implementation of the findings/products and recommend possible actions to address these issues; and (d) recommend methods of identifying and measuring the impacts associated with implementation of the findings/products. Implementation of these recommendations is not part of the research project and, if warranted, details of these actions will be developed and implemented in future efforts.
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
K. If the team proposes a Principal Investigator who is not an employee of the Prime Contractor, or if the Prime Contractor is proposed to conduct less than 50% of the total effort (by time or budget), then section five of the proposal should include: (1) a justification of why this approach is appropriate, and (2) a description of how the Prime Contractor will ensure adequate communication and coordination with their Subcontractors throughout the project.
L. All budget information should be suitable for printing on 8½″ x 11″ paper. If a budget page cannot fit on a single 8½″ x 11″ page, it should be split over multiple pages. Proposers must use the Excel templates provided in the Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs.