Seismic Response Analysis and Seismic Isolation Design of Large-Span Through Arch Bridges

Large-span through arch bridges have complex structures and certain spatial coupling effect. Based on a 216 m long span through arch bridge with steel-box ribs and steel-box girders, a three-dimensional spatial finite element model is established to study the dynamic characteristics and seismic response through response spectrum analysis. The fixed bearings and the fixed piers are vulnerable parts for controlling seismic design. And then cable-sliding friction aseismic bearings (CSFAB) are adopted for seismic isolation design. The analysis results indicate that CSFAB can effectively reduce the seismic response of the substructure, and also prevent excessive displacement of beams. It is a cost-effective means of seismic isolation.