Abstract
Steel bridges are generally considered to perform well during seismic activity. Nevertheless, they still suffered much unexpected seismic damage in the Kumamoto earthquake, especially seismic pounding damage. Previous studies on bridge pounding damage have generally focused on reinforced concrete bridges. However, steel bridges' dynamic characteristics are more complex, the stiffness of each component varies significantly, and relevant research remains limited. Therefore, the numerical simulation method is adopted in this paper to study the pounding damage of simple-supported steel bridges under seismic events in detail. The multiscale, fine three-dimensional finite element model was built using the general finite element calculation platform Abaqus, and dynamic implicit analysis was performed. Numerical results show that large and near-fault seismic activity results in obvious pounding damage to steel beams. Specifically, longitudinal pounding causes damage to the steel beam's ends; however, the damage is typically localized and mild. Lateral pounding further causes direct damage to the steel beams, resulting in extensive and serious damage. Horizontal pounding which combines longitudinal and lateral causes rotation of the bridge deck and aggravates the lateral damage to steel beams. In addition, a pounding identification method based only on displacement data is proposed, and a feasible preventive measure for lateral pounding damage is suggested.