Development of a Strategy To Address Load Posted Bridges Through Reduction in Uncertainty in Load Ratings [Project Title from Cover]

US Transportation Collection2022PDFTech ReportHueste, Mary BethHurlebaus, StefanMander, JohnPaal, StephanieTerzioglu, TevfikStieglitz, MatthewKabir, NuzhatTexas A&M Transportation InstituteTexas. Dept. of Transportation. Research and Technology Implementation OfficeUnited States. Department of Transportation. Federal Highway AdministrationTexas A&M Transportation InstituteTexasUnited StatesBridge designBridgesLoad factorUncertaintyAnalysisSteel bridgesConcrete bridgesRefined analysis,Refined load ratingLoad posted bridgesComposite actionEnd restraintFHWA/TX-19/0-6955-R1-Vol30-6955September 2017\u2013October 2019Maintaining the functionality of the transportation infrastructure depends on the successful management of aging bridge assets. Departments of Transportation rely on the load rating process to evaluate the sufficiency of the bridge structures in their state, and post load restrictions if the capacity of a bridge does not meet the maximum load effect based on the current legal loads. Removing load postings is always of interest because there can be commerce, traffic, and emergency egress issues due to rerouting of vehicles. Posted structures come in various shapes and sizes, built in different eras and environments, and exhibit vastly different structural behaviors. As such, there is no clear-cut single solution for addressing the possibility of removing postings. In this study, strategies have been developed to reduce uncertainty in load rating procedure in a safe and appropriate manner to potentially increase or remove the load postings of typical steel and concrete bridges. The Volume 1 Report documents findings including a review of the state-of-the-practice and state-of-the-art for load rating existing bridges, a review and synthesis of the bridge characteristics of load posted bridges in Texas, and the basic load rating analysis conducted for selected representative bridges to identify the controlling limit states. The Volume 2 Report provides details of further study for typical bridges including refined analysis for more accurate prediction of load distribution, load testing, model updating and calibration, and refined load rating analysis. This Volume 3 Report provides specific recommendations for refined load rating analysis for the four selected bridges types, and provides detailed refined load rating examples for each bridge type. The effect of each refinement on the revised load ratings is evaluated, and the implications for potentially increasing the posted loads or removal of load posting are discussed.143