基于摩擦摆支座的大跨度双拱塔斜拉桥减隔震研究

Study of Vibration Mitigation and Isolation for Long-Span Cable-Stayed Bridge with Double Arch Pylons Based on Friction Pendulum Bearings

为研究摩擦摆支座对斜拉桥的减隔震效果,以某双拱塔斜拉桥为工程背景,考虑桩-土-结构相互作用(PSSI)的效应,基于摩擦摆支座的力学特性建立桥梁结构空间有限元模型,进行动力特性分析、地震响应研究与抗震验算。结果表明:采用摩擦摆支座减隔震后,结构的自振基本周期较原结构明显延长,有利于改善结构的抗震性能;不同的地震动输入方式对控制截面的内力影响不同,E2地震下的响应值均要比E1地震下大;E1、E2地震作用下,结构各主要控制截面的安全系数均大于1,结构只发生可修复性损伤,满足结构的抗震性能目标要求。

To study the vibration mitigation and isolation effect of friction pendulum bearings on cable-stayed bridge,a cable-stayed bridge with double arch pylons was taken as the study background.The spatial finite element model of the bridge structure was established,taking into account the pile-soil-structure interaction(PSSI)and the mechanical property of the friction pendulum bearing.The dynamic property of the structure was analyzed,the seismic response was studied,and the anti-seismic vibration check was conducted.The results show when the friction pendulum bearings were used,the basic natural vibration period of the structure obviously extended,which was beneficial to the improvement of the anti-seismic performance of the structure.Different ground motion input will have different effect on the internal forces of the control cross-section,and the response values in the context of E2 earthquakes are all greater than those in the context of E1 earthquakes.Under the action of E1 and E2 earthquakes,the safety coefficients of each main control cross-section of the structure are greater than 1,and the structure only experience repairable damages,meeting the requirements of anti-seismic performance target of the structure.