AASHTO Load Rating Provisions for Implements of Husbandry (2020)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

3 Research Approach NCHRP Project 12-110 consisted of the following 12 tasks in four phases. At completion of each phase, the NCHRP project panel and the program officer reviewed the interim report and approved advancement to the next phase. 2.1 Phase I—Planning Task 1. Conducted a literature review of relevant domestic and international research and guidelines. The domestic review included research conducted through NCHRP; the Strategic Highway Research Program 2; FHWA; and other national, state, and pooled fund-sponsored research. The review covered research findings, existing guidelines, and owner and industry experience. Task 2. Synthesized the literature review to identify the knowledge gaps for IoH. These gaps have been addressed in the final product or in the suggested future research as budget permitted. Task 3. Proposed an analytical program to investigate the load rating of IoH. The proposed analytical program should be based on currently available data. At a minimum, the research should address (1) different bridge types and materials and (2) development of the load enve- lope for IoH, load distribution factors, live load factors and load combinations, and dynamic impact factors. The LRFR specifications shall be calibrated based on proposed reliability indexes, load factors, and load distribution. Task 4. Prepared Interim Report No. 1 that documents Tasks 1 through 3, as well as the data archiving plan, and provided an updated work plan for the remainder of the research no later than 3 months after contract award. The updated plan described the process and rationale for the work proposed for Phases II through IV. 2.2 Phase II—Analytical Program Task 5. Executed the analytical program according to the approved Interim Report No. 1. Task 6. Developed a set of protocols to evaluate IoH with various configurations for load rating and overload permits. Task 7. Identified areas of the AASHTO specifications (i.e., the AASHTO MBE and the AASHTO BDS) that require modification and describe the calibration process. Task 8. Prepared Interim Report No. 2 that documents Tasks 5 through 7 and provided an updated work plan for Phases III and IV no later than 18 months after approval of Phase I. C H A P T E R 2

4 Proposed AASHTO Load Rating Provisions for Implements of Husbandry 2.3 Phase III—Proposed Provisions to the AASHTO Specifications Task 9. Developed specifications and commentary language for proposed provisions to the AASHTO specifications, supported with examples. Task 10. Prepared Interim Report No. 3 that documents Task 9 of Phase III no later than 6 months after approval of Phase II. 2.4 Phase IV—Final Products Task 11. Revised the proposed provisions of the AASHTO specifications after consideration of review comments, then prepared ballot items for consideration by the AASHTO Highway Subcommittee on Bridges and Structures. Task 12. Prepared final deliverables including (1) a final report that documents the entire research effort; (2) the proposed provisions to AASHTO specifications, load-rating examples, and protocols; and (3) a standalone technical memorandum titled “Implementation of Research Findings and Products.”