Performance of Girder Bridges under the Composite Action of Blast Loads and Earthquakes

摘要

The research focuses on the dynamic performance of girder bridges and the applicability of cable-sliding friction bearing subjected to blast load and earthquake. In order to accomplish this, numerical simulation and scale model test are performed. In numerical simulation, two seismic waves combing with blast load of 450kg TNT are applied to the girder bridge separately by using software LS-DYNA. After analyzing the area of damage and longitudinal displacement, results show that the most remarkable displacement change of main girder appears when blast occurs at the time that seismic response arrives at the maximum value. Based on the existing research, cable-sliding friction bearing is suggested to be adapted. Next, scale model test is conducted considering two different damping bearing systems and three series of tests are performed to verify the effectiveness of the cable-sliding friction bearing system. The data collected from the test shows that the bearing could prevent beam falling and therefore improve the safety of girder bridges.