STRUCTURAL REDUNDANCY ANALYSIS FOR STEEL TRUSS BRIDGES IN JAPAN

Abstract

The structural redundancy for steel truss bridges is investigated through the case studies for a simply supported steel truss bridge constructed in 1960 and a three-span continuous steel truss bridge designed as a standard model bridge in 1980. Here, the structural redundancy means the capability of a bridge to continue to carry loads after the failure of a member or a part of the bridge. To evaluate the redundancy, the linear structural analysis is employed as a standard procedure. The applicability of linear analysis to redundancy evaluation is examined by comparing with the nonlinear analysis results. In addition, detailed nonlinear FE analysis for a joint of truss bridge is carried out to check effect of a joint failure on the redundancy. Finally, on the basis of the study results, some recommendations toward rational bridge maintenance are presented.