Damage and dynamic response of precast bridge box girder und er blast loading

Abstract

This study numerically investigates the damage and dynamic response of precast bridge box girder subjected to blast loads. Numerical models are developed using LS-DYNA and validated against experimental tests. Then the calibrated modeling method is used to perform depth research on the effects of scaled distance, height-span ratio and concrete strength on the behavior of precast box girder subjected to blast loads. The results indicate, reduction of the scaled distance will transform the failure mode of precast box girder and increase the damage level. Conversely, increasing the height-span ratio will reduce the damage range in the transverse direction, but local damage will expand. Last but not least, enhancing the concrete strength can improve the anti-blast performance of girder. But when the concrete strength exceeds 32.4 MPa, the contribution to anti-blast performance is not obvious.