Analysis about Seismic Constrained System of Single Tower Cable-Stayed Bridge

Abstract

Taking Shihezi single tower cable-stayed bridge as the engineering background to establish finite element seismic model, using the nonlinear dynamic time history to get seismic analysis of the bridge under strong earthquake. In order to study the effect of damping constrained system on single tower cable-stayed bridge's seismic performance, this paper makes a contrastive analysis about the longitudinal, lateral different constrained system. In the longitudinal direction, we make a seismic calculation under the rare earthquake action while the single tower cable-stayed bridge respectively use different constrained system, such as rigid system, floating system, vertical supporting system, vertical support and elastic cable system, vertical support and viscous damper (FVD), etc, drawing the following conclusion: When using the movable support as the vertical bearing, friction resistance of the bearing can greatly improved the seismic performance of the structure, so its influence should be considered while calculating, the system that includes vertical support and the FVD is the optimal longitudinal seismic constrained system correspondingly. In the lateral direction, we respectively make a seismic calculation under the rare earthquake action while the pylons respectively use rigid system, floating system, transverse hinged, transverse free, vertical support and elastic cable, vertical support and viscous dampers (FVD) etc different constrained forms, transition pier respectively use transverse hinged, transverse free, lead rubber bearing, vertical support and viscous dampers (FVD) etc different constrained forms, drawing the following conclusions: If the force of transition pier stress has no conclusive effect on the design, the main tower with vertical support and viscous dampers while the transition pier with transverse hinged is the relatively optimal constrained system, If the force of transition pier stress has conclusive effect on the design, the main tower with vertical support and elastic cable while the transition pier with lead rubber bearings is the relatively optimal constrained system.