Effects of using lower steel grade on the critical members to the seismic performance of steel truss bridge structures

This paper investigated the effect of using lower steel grade material on the critical members of steel truss bridge structure to their maximum stress and strain. Full truss bridge structure with uniform and not uniform steel grade on their critical members were used as the present models. Two direction earthquake motion were applied on the bridge supports. Results indicated that using lower steel grade in the critical members in the truss bridge resulted higher strength reduction in carrying earthquake load than any other parts in the steel truss bridge structure.