Assessment of redundancy protocols for short-span steel truss bridges

Owner agencies and state transportation departments have expressed concern over costly inspection requirements for short-span steel truss bridges due to the potential designation of members as fracture-critical. This designation has a direct impact on future implementation of these structures as well as perceived inherent safety in existing bridges of this type. Throughout the years, researchers have developed methodologies to determine the degree of load-path redundancy that such structures exhibit, which, once employed, may eliminate the potential for fracture-critical designation, alleviating inspection costs and promoting these types of structures in highway bridge applications. This paper presents the results of a highly accurate, nonlinear finite element investigation of the load-path redundancy of a representative short-span steel truss bridge, which is benchmarked against physical load testing of the bridge. Once validated, the model will undergo a series of severed member analysis to determine the inherent levels of load-path redundancy.