Steel box girders are widely used in cable-stayed bridges, while they are prone to severe damage under explosions. This paper investigates the deformation and energy dissipation of steel box girder of cable-stayed bridges under blast impact, caused by the accidental explosions of tanker trucks and vehicles. In this study, Hypermesh and LS-DYNA are employed to simulate the dynamic responses of a real steel box girder cable-stayed bridge under explosions. The deformation response and energy absorption of the box girder under explosions are investigated. Several failure modes and failure processes are analyzed and summarized. The findings indicate that the failure mode of an orthotropic steel bridge panel under blast impact is primarily local damage, with the damage process being divided into three stages: local plate deformation, fragment formation, and petal formation. For bridge deck explosions, the main energy dissipation components of steel girders are the bridge panel, web, diaphragm and rib stiffeners. The research results can provide the basis for the follow-up study on the anti-explosion safety of bridge structures.

Cable-stayed bridge, steel box girder, deformation response, energy dissipation, explosion load