Experimental study on transverse pounding reduction of a high-speed railway simply-supported girder bridge using rubber bumpers subjected to earthquake excitations

Abstract

The pounding between shear keys and bearing padstones has been identified as one of critical factors affecting transverse seismic responses of bridges. It is inevitable since the role of shear keys is to limit the excessive displacement of girders during earthquakes. Therefore, it is necessary to perform investigations on reducing the adverse transverse pounding effects on bridges. This paper presents an experimental study on the transverse pounding reduction of a high-speed railway (HSR) simply-supported girder bridge using rubber dampers. A series of shaking table tests were performed on a 1/6-scaled bridge model to investigate the influence of pounding on transverse seismic responses of the bridge model and the pounding reduction effects of rubber bumpers. The fast Fourier transform (FFT) of seismic responses was performed to further discuss the pounding reduction mechanism of rubber bumpers. The experimental results showed that the rubber bumpers are effective on reducing the transverse seismic responses. The pounding between shear keys and bearing padstones evidently increases the high frequency seismic responses of the bridge model. However, the presence of the rubber bumpers can significantly weaken the high frequency responses, and thus mitigates the adverse seismic responses caused by the pounding. In addition, a numerical model incorporating the pounding and rubber bumpers was developed to verify the validity and the accuracy of the numerical modeling. A good agreement between the calculated results and the experimental ones was found.