A replacement to Article 6.10 of the AASHTO "LRFD Design Bridge Design Specifications" was proposed to the Subcommittee on Bridges and Structures (SCOBS) (June 2003). With data obtained from AASHTO's Virtis Load Rating System, approximately 200 steel bridges were analyzed and reviewed by using the proposed load and resistance factor design (LRFD), the current LRFD, and the current load factor design methods. The engineering process, a comparison of the results obtained by the different methods, and the observed trends are outlined. The goal was to determine the effects that the proposed AASHTO LRFD Article 6.10 modifications had on bridges before the adoption of the specification revisions by the AASHTO SCOBS. Oral presentations at the AASHTO Annual Meeting helped bridge engineers to understand the effects of the new version of Article 6.10 on practice. This process, which uses NCHRP 12-50, is outlined, and the results are systematically reported. This is the first truly systematic validation of a significant specification modification before its adoption. The experience is noteworthy and should be documented. This process could become a trend in specification development.
Samenvatting