Nonlinear dynamic response analysis of reinforced concrete continuous girder bridge under strong earthquake excitations

To explore the seismic damage evolution and failure history of the continuous girder bridge model, a nonlinear dynamic response analysis was made based on the shaking table test of a scaled 1∶3 bridge model. Collisions between the girder and the abutment and those between the girder and the shear key were discussed to compensate for test results without considering the impact of collision. The analysis results indicate that numerical analysis results are consistent with those from the shaking table array test. The main failure mode of a two-span continuous girder model is the destruction of piers, and the lower cross section of middle pie is the vital place. The bridge model will not collapse under longitudinal shaking on the condition that the acceleration response spectrum of the girder is less than 17.4 m/s2. If the collision between the girder and the abutment is considered, the acceleration of main girder becomes larger, the displacement of main girder becomes less, and the internal forces of pier column will be less. The effects are more significant with the decrease of contact gap. If considering the collision between the girder and the shear key, the acceleration of main girder increases, and the force of pier column increases with the increase of contact gap. This study provides references for subsequent anti-collapse design and seismic retrofit of concrete continuous girder bridges. © 2016, Editorial Department of Journal of Southeast University. All right reserved.