Seismic Fragility Analysis of Skew Bridges with Cable-Slide Modular Expansion Joints

Abstract:

In order to investigate the influence of sliding-cable modular expansion joints on the seismic performance of a three-span concrete skew continuous beam bridge with a 30° skew angle， sliding-cable modular expansion joints are adopted to restrict the rotation of skew bridge girders， the seismic performance of the skew bridge equipped with sliding-cable modular expansion joints in pulse-like and no pulse-like ground motions is explored using analytical fragility curves， and the post-earthquake repair cost curve is proposed to evaluate the seismic performance of bridge structures. The results show that the fragility of piers and bearings is significantly reduced after cable-sliding modular expansion joints are adopted. Under the influence of velocity pulse effect， the fragility of both skew bridge bearings and piers with cable modulus expansion joints significantly increase but the structure failure mode remains the same， and the use of cable-sliding modular expansion joints effectively reduces the seismic repair cost of the bridge regardless of whether ground motions are pulse-like or not.

Key words:skew bridge;sliding-cable modular expansion joint;seismic fragility analysis;seismic repair cost;velocity pulse effect