Dynamic Response and Design Optimization of Box Girder Bridge with Corrugated Steel Webs Subjected to Blast Loads

Throughout the service life, bridge structures may face blast hazards from military conflicts, terrorist attacks, and accidental explosions. Dynamic responses and damage modes of box girder bridges with corrugated steel webs under blast loading remain scarce. This study investigates the dynamic response and optimal design of box girder bridges with corrugated steel webs under blast loading. A box girder bridge model with corrugated steel webs is established through the software LS-DYNA, and the dynamic response of the bridge model subjected to blast loads is studied. Parametric studies are conducted to evaluate the effects of key geometric parameters, including the folding angle, height–span ratio, and dip angle of corrugated steel webs, on the blast-resistance performance of the bridge. The results indicate that a folding angle of 55° provides optimal blast resistance by balancing local stiffness and stress concentration. The 3.0 m height of corrugated steel webs maximizes the energy absorption capacity of corrugated steel webs while minimizing mid-span residual deflection. A dip angle of 85° ensures effective deformation constraint and load transfer, reducing damage in both the upper and bottom bridge decks. This study highlights the critical role of corrugated steel web geometry in enhancing blast resistance and provides practical guidelines for optimizing the design of box girder bridges with corrugated steel webs under extreme loading conditions.