竖向动压力对FPS隔震连续梁桥地震响应影响研究  

Research on the Influence of Dynamic Vertical Pressure on the Seismic Response of Continuous Girder Bridge Isolated with FPS

作　　者：焦常科 李爱群[2,3] 伍小平[1] 

机构地区：[1]上海建工(集团)总公司,上海200080 [2]东南大学土木工程学院,江苏南京210096 [3]北京建筑大学土木与交通工程学院,北京100044

出　　处：《应用基础与工程科学学报》2017年第4期733-741,共9页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51408355)

摘　　要：摩擦摆支座因其稳定的力学特性而广泛应用于中小跨径的桥梁隔震.文中首先根据FPS力学模型的特点,剥离出摩擦力项并给出了考虑动压力对回复力中摩擦力项影响的有限元实现,以较准确模拟FPS的力学特性.以单自由度模型为例,研究了动压力和摩擦限值对其动力响应的影响.其次以四跨连续梁桥为例,建立2种不同FPS支座布置参数的平面动力分析有限元模型,研究了同时考虑竖向和水平地震作用时,结构时域动力响应特点.文中研究表明:考虑动压力影响后,FPS支座的滞回环不再是标准的平行四边形,呈现出一定的波动性;采用FPS隔震连续梁桥在考虑动压力对摩擦力项影响后,可避免墩底反力高估.Friction pendulum systems bearings have been widely used in the seismic isolation of medium and short span bridges for their stable mechanical behavior. The approach for representing the behavior of FPS was presented in this paper with the effect of dynamic axils force on the friction considered by extracting the friction item of FPS, and the influences on dynamic response were demonstrated with the single degree of freedom system with FPS bearing. A four-span continuous bridge isolated with FPS bearings was taken as an example to analysis the character of seismic response of the structure under the excitations of vertical and longitude ground motions in time domain and two plane finite element model were established with different configurations of FPS. Results show that, the hysteresis loops of FPS appear not to be a standard shape of parallelogram and some fluctuations arise. Over estimation of reaction of piers of continue beam bridge isolated with FPS under seismic ground motions can be avoided when the effect of dynamic axils force on the friction limit of FPS considered.

关 键 词：摩擦摆支座 隔震桥梁 地震响应 

分 类 号：U448[建筑科学—桥梁与隧道工程]