Study On Collision Effect Of Long-span Cable-stayed Bridge Between Main Span And Approach Span

In recent years,with the earthquake frequently occurring,huge losses and difficulties to earthquake relief would be brought when the bridge,as a lifeline engineering,collapsed during the earthquake.Cable-stayed bridge is one of the most widespread bridges with the characteristics of long-span capability,economization of materials,simple construction and beautiful shape.The floating system was often designed for the long-span cable-stayed bridge.A very large displacement would be occurred under the strong earthquake which would cause a collision between main span and approach span,even a girder falling of approach span.In view of this,collision factors,traveling wave effect on collision and measures for collision avoidance and collapse-proof were studied by taking the collision effect between main span and approach span as the research object.The main contents are as follows:(1)Such aspects of research were reviewed as collision factors between main span and approach span,simulation method of collision effect and measures for collision avoidance and collapse-proof,based on the comprehensive reading and understanding of related references home and abroad.(2)Based on a typical long-span cable-stayed bridge,influence of period ratio,expansion joint gap and PGA on internal force and displacement under four different sites was studied by using SAP2000 to establish finite element model.(3)Based on the analysis of long-span cable-stayed bridge seismic response by traveling wave effect,internal force,relative displacement between bridge piers and girders and relative displacement between main span and approach span were studied under four different sites.(4)A new device with limit component and energy dissipation component was researched based on the comprehensive reading and understanding of measures for collision avoidance and collapse-proof home and abroad.The reasonable parameter value of mechanical properties was studied.The damping effect of coupling-beam limit device and the device with limit component and energy dissipation component was analyzed by using uniform excitation and traveling-wave excitation.