Development of Cable- Sliding Friction Aseismic Bearing for Bridges

  • Prof Wan-cheng Yuan, State Key State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China, China
  • Mr Xin-jian Cao, State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, China
  • Dr Pak-Chiu Cheung, Architectural Services Department, Hong Kong Special Administrative Region Government, China
  • Mr Bin-bin Wang, State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, China
  • Mr Zhao-jun Rong, Jiangsu Wanbao Bridge Accessories Co Ltd, Changshu, China

A new aseismic bearing system has been developed based on the advantages of typical seismic isolation devices for bridges reviewed in this paper. It is noted that in currently used bearings with a friction sliding surface of polytetrafluroethylene (PTFE) and stainless steel, displacements induced by lateral force are unconstrained. In this proposed Cable- Sliding Friction Aseismic Bearing with a shear bolt and cables attached to the base of the bearing, restoring forces are provided to limit the displacements of the sliding component. Parameters of stiffness and length of the cables, magnitudes of shear bolt strength and free movement under minor and moderate earthquakes forces are controlling design factors. To demonstrate the effectiveness of the new system, a four-span continuous girder bridge is analyzed with the bearing assumed in place. Numerical finite element simulation approach and experimental testing of a prototype bearing subjected to vertical load and quasi-static lateral load tests are carried out to determine hysteretic responses. It is shown that the numerical simulation data agree well with the experimental force-displacement hysteretic results, confirming the viability of the bearing system.