Seismic Behavior of the Combined Viscous-Steel Damping System for a Long-Span Suspension Bridge Considering Wave-Passage Effect

Abstract

This study investigates the working mechanism and seismic behavior of the Combined Viscous-Steel Damping System (CVSDS) considering the longitudinal wave-passage effect. In the CVSDS, the operational status of the fluid viscous damper (FVD) and the steel damper (SD) can be switched by the fuse–lock device (FLD), which is triggered by the output force of the FVD. The configuration and working mechanism of CVSDS are introduced in detail. A test model is manufactured and examined by cyclic tests to verify its fusing–locking function during cyclic motions. The numerical model of CVSDS is proposed based on the experimental result. The fusing–locking behavior and seismic reduction effectiveness of CVSDS installed in a long-span bridge is analyzed, in which the wave-passage effect is considered. The results show that the fuse–lock function under dynamic loading can be achieved by the proposed FLD. The occurrence condition of the locking mechanism activation depends on the viscous damping force. The traveling wave will induce a delay of the locking time, cause large locking intervals between CVSDSs installed at different positions, and lead to a larger required moving capacity of the CVSDSs. The mitigation effectiveness of CVSDS is significantly reduced due to the wave-passage effect.