Dynamic response and damage assessment of a prestressed T-shaped simply supported girder bridge under contact explosion

Abstract

Combined with model experiments and numerical simulations, the dynamic response of a 1:10 scaled T-shaped simply supported girder bridge under the contact explosion was researched, and the typical failure modes of the bridge, the bridge deck overpressure distribution and acceleration response characteristics were analyzed; The damage distribution of the bridge after the explosion was discussed, and the classification method of the damage degree of each area of the prestressed T-shaped simply supported beam bridge deck after the explosion was proposed. The results showed that the overall failure mode of the bridge was a combination of local failure and overall deformation, mainly local punching failure at the location of the bridge deck blast center; in view of the characteristics of the lateral weak connection of the upper structure of the prestressed T-shaped simply supported beam bridge, after the explosion, the bridge could be divided into 4 typical damage areas: the bridge decks in region I–III were severely damaged, which were dangerous regions and could not continue to bear the load; region IV needed to be repaired and reinforced after evaluation for temporary passage or normal use; other parts were almost intact and could be used directly for temporary traffic or normal use after assessment of the bearing capacity. Meanwhile, simplified method for dividing the damage region after the anti-blasting of the bridge deck was obtained by parametric discussion. The research results could provide a reference for the post-blast damage assessment of prestressed T-shaped simply supported girder bridges.