Study of seismic performance of three-tower cable-stayed suspension bridges

Xin-Jun Zhang, Zhi-Yong Hu and Dong-Jie Xu

Abstract

The longitudinal flexibility of the center tower in three-tower cable-stayed suspension bridges(3TCSSB) significantly reduces structural stiffness, rendering these systems highly vulnerable to seismic actions. In this work, the dynamic characteristics and seismic performance of a 3TCSSB with double 1400 m main spans were numerically investigated using MIDAS/Civil software. Nonlinear time-history and response spectrum analyses were conducted to evaluate the structural responses under horizontal and vertical seismic excitations. A comparative analysis with three-tower cable-stayed(3TCSB) and suspension bridges(3TSB) of equivalent spans reveals that 3TCSSB exhibits superior seismic performance due to its balanced stiffness and reduced seismic responses. The findings propose 3TCSSB as an optimal structural system for kilometer-scale multi-tower cable-supported bridges in seismically active regions.

Key Words

dynamic characteristics; nonlinear time-history analysis; response spectrum analysis; seismic response; threetower cable-stayed suspension bridge

Address

Xin-Jun Zhang: College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, P.R. China; Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology of Zhejiang Province, Hangzhou 310023, P.R. China Zhi-Yong Hu: College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, P.R. China Dong-Jie Xu: College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, P.R. China

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