Abstract:In order to study the damage effect of large mass falling objects on bridges, based on the drop accident of highway bridge body during the construction process of a railway bridge crossing a highway, the display dynamic analysis software LS_DYNA is used to conduct the numerical simulation. Taking a 32 m-span railway box girder as the research object, a refined model is established to calculate and give the detailed simulating parameters, such as the material type, reinforced concrete coupling mode and element size, which restores the whole accident process in more detail. The damage status and mid span displacement of the box girder, as well as the stress state data of steel bars are analyzed. The results show that compared with small mass impacts such as cargo throwing, the box girder is not only locally damaged such as concrete falling off in the contact zone, but also overall damaged such as cracks along the bridge direction and mesh cracks in the flange plate under the large mass falling impact. And a small portion of ordinary steel bars reaches the yield stress, and the prestressed tendons have not yielded.
