Numerical Simulation of a Long-Span Steel Truss Bridge Subjected to Blast Loads

Few studies have focused on the blast load effects on steel truss bridges. To address this research gap, this paper conducts an extensive investigation on the above-deck blast loads on a long-span steel truss bridge. The nonlinear dynamic response and damage modes of reinforced concrete (RC) decks and steel members of the bridge under blast loads are numerically studied using the *Load_Blast_Enhanced (LBE) function and Multi-Material Arbitrary Lagrangian-Eulerian (MM-ALE) method in LS-DYNA to identify a cost-efficient approach with reasonable accuracy to simulate a long-span steel truss bridge subjected to blast loads. The LBE method is proved to be more conservative and cost-efficient than the MM-ALE method for simulating blast load effects on the structures. A high-fidelity finite element model of the bridge (i.e., I-35W truss bridge) in LS-DYNA based on the multi-scale modelling technique and the LBE function to simulate blast loads is developed to investigate the structural response under several blast scenarios. The effectiveness of ultra-high-performance concrete (UHPC) in protecting the steel truss members from blast load effects is also been investigated. The results provide valuable insights for bridge owners on the probable response and possible protective measures for long-span steel truss bridges against intensive blast loads.