考虑行波效应下的多塔斜拉桥减隔震体系研究

摘要

A nonlinear three-dimensional finite element model was established for a multi-pylon cable-stayed bridge.Seismic response analyses of the bridge under excitations considering the travelling wave effect were conducted for both the Conventional System (CS)and the Seismic Isolation System (SIS).The results show that:(1 )For the CS,the traveling wave effect can significantly increase the internal force of upper tower bot-tom;but the SIS that uses the CSFAB has a decreasing amplitude ratio;(2)Sesismic responses of the pier decrease at the loading cases considering the traveling wave effect and the SIS can further reduce the pier forces;(3)Bearing displacement of the approach span increases obviously under traveling wave effect;there-fore,the CSFAB is recommned to be adopted;(4)The relative displacement between the main spane and ap-proach span was further enlarged under the traveling wave effect.Therefore,it is suggested that restrain de-vices and bumper devices should be set up at this place in order to improve seismic behaviors.%以一座主跨908 m 的多塔斜拉桥为研究背景，建立全桥动力计算模型，分析了行波效应下该结构常规体系与减隔震体系的地震响应，结果表明：①对于常规体系，行波效应会增大上桥塔内力，但采用拉索减震支座的减隔震体系具有较好的减震率；②考虑行波效应对桥墩抗震有利，而减隔震体系会进一步降低桥墩内力；③减隔震体系可以将主桥支座位移控制在要求范围内，对于引桥，考虑行波效应时，支座位移增大明显，也建议采用拉索减震支座；④行波效应下，主-引桥相对位移增大，建议在主-引桥间设置连梁装置和缓冲装置，以提高抗震性能。