支座的仅受压特性对大跨双层斜拉桥地震响应影响研究  

Research on Influence of Compression-only Behavior of Bearings on Seismic Response of Double-decks Long-span Cable-stayed Bridges

作　　者：焦常科 李爱群[2,3] JIAO Changke;LI Aiqun(Shanghai Construction Group, Shanghai 200080, China;School of Civil Engineering, Southeast University, Nanjing 210096, China;Beijing University of Civil Engineering and Architecture, Beijing 100044, China)

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,北京100044

出　　处：《应用基础与工程科学学报》2018年第2期380-390,共11页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51408355)

摘　　要：由于边跨与中跨跨重比大,通常在计算大跨斜拉桥时域地震响应时,可忽略桥梁支座的仅受压特性;但若跨重比小或竖向地震较为明显时,地震中可能出现梁端上抬的现象.本文首先给出考虑支座仅受压特性的简化模拟方法,其次以一座大跨双层斜拉桥为例,研究考虑支座仅受压特性后,结构地震响应的特点及地震中梁端可能出现的上抬现象.考虑支座仅受压特性后,文中研究表明：（1）边跨与中跨跨重比小或竖向地震较明显时,梁端可能出现上抬现象,应当引起充分重视;（2）如果地震中会出现支座脱开现象,该特性对大跨度双层斜拉桥边跨辅助墩墩间加劲梁挠度和墩顶附近腹杆轴力及部分斜拉索内力等地震响应影响很明显.The behavior of compression-only of bridge bearing was neglected usually during the calculation of seismic responses of long-span cable stayed bridge in time-domain,since that the gravity ratio of girder between side-span and mid-span was large enough. However,the uplifting may happen to the end of girder,when the ratio is relatively small or the vertical ground motions are strong. The simplification model for the behavior of compression-only of bearings was presented in the paper firstly. A long-span double-deck cable-stayed bridge was taken as an example to study the influence of such behavior on the seismic response of cable-stayed bridge and the phenomenon of uplifting happened to the end of girder when the behavior of compression-only was considered in the paper. Results show that：（1） The phenomenon of uplifting may happen to the end of girder when the behavior of compression-only of bearings is considered,with small gravity ratio between side-span and mid-span or strong vertical motion arise,on which much attention should be paid.（2） As to long-span double-deck cable-stayed bridge,the behavior of compression-only of bearings have significant influents on the seismic response of side-span,such as the deformation of girder between piers,axial force of web members near the top of piers,and the time history of cable force,et al.,when the uplift occurs during the motion.

关 键 词：支座脱开 仅受压特性 梁端上抬 双层斜拉桥 地震响应 

分 类 号：TU997[建筑科学—市政工程]