Assessment of seismic responses of skewed bridges with bidirectional collision effect

Abstract

Unbonded laminated elastomeric bearings have been used widely for skewed highway bridges in China. This type bearing is likely to slip during an earthquake, which will lead to large girder displacement and collision phenomenon. In order to discuss the effect of different collision models and design parameters on the seismic response of skewed bridges in China, 3D beam-stick models of three-span highway bridges with skew angles varying from 0°to 60°are developed in this paper. The results show that the collision effect is the principal contributor to girder rotation. The collision model considered nonlinear property in this paper can capture the irregular behavior of skewed bridges correctly. The uneven collision phenomenon will be more obvious for changing the initial gap of shear keys, and the overall seismic responses are likely to become complicated. Then, an appropriate gap is recommended to reduce the seismic damage of skewed bridges.