Impact in Truss Bridge Due to Freight Trains

Abstract

The dynamic responses of a railway bridge members due to vehicle‐track‐bridge interaction were investigated for the effects of vertical and lateral track irregularities, approach track quality, and bridge damping. In each case, a train consisting of three vehicles moving at constant speed was simulated traveling on the bridge. It was found that: (1) Greater approach irregularities produce higher impact factors and dynamic forces in bridge members; (2) impact factors in members with low static stress are high, but the dynamic stresses produced are low; (3) in general, impact factors reduce slightly due to bridge damping; and (4) the dynamic forces in lower lateral bracing members are small as compared to their allowable values.