基于盆式支座与黏滞阻尼器的某大跨度斜拉桥减震研究

Research on Damping of a Long Span Cable-Stayed Bridge Based on Pot Bearing and Viscous Damper

以一座大跨度斜拉桥为研究对象,用Midas Civil软件建立其全桥三维有限元模型。针对其在E2地震作用下位移超过限值问题,提出在桥墩与上部结构间布置盆式支座+黏滞阻尼器的减震方案,对黏滞阻尼器阻尼指数进行优化分析,得到最优阻尼指数,进一步对其位移及内力进行了减震效果分析。分析结果表明,主墩支座位移从596mm降至216mm,最大减震效果达63.8%,满足规范要求;在主跨部分布置盆式支座和黏滞阻尼器对其他跨桥墩墩底弯矩也有一定降低效果,两者耗能特性得到充分发挥,能够有效降低结构的地震响应,证明了盆式支座+黏滞阻尼器减震方案的合理性和可行性。

A long span cable-stayed bridge is studied in the paper, and the 3-dimensional finite element model for the whole bridge is established by Midas Civil software. Regarding the issue of exceeding the displacement limit value under E2 earthquake, a vibration reduction scheme is proposed with pot bearing and viscous damper distributed between pier and superstructure. After optimizing the damping index of viscous damper, and the optimal damping index is obtained, and furthermore the damping effect of displacement and internal force are analyzed. The results show that the displacement of the main pier bearingis reduced from 596mm to 216mm, and the highest damping effect is up to 63.8~, which can meet the requirement of standards. Pot hearing and viscous damper that distributed in the main span section of the bridge have a certain reduction effect to the other cross pier bottom bending moment, their energy consumption characteristics perform well, which can effectively reduce the seismic response of the structure. Therefore, the rationality and feasibility of the scheme by pot bearing and viscous damper are verified.