随机地震多点激励作用下对称结构的扭转效应  

Torsional Response of Symmetric Building Structures Due to Multi-support Random Seismic Excitations

作　　者：张猛[1,2] 赵桂峰[1] 马人乐[2] 何敏娟[2] 

机构地区：[1]郑州大学土木工程学院,河南郑州450001 [2]同济大学建筑工程系,上海200092

出　　处：《郑州大学学报（工学版）》2011年第2期54-58,共5页Journal of Zhengzhou University（Engineering Science）

基　　金：中国博士后科学基金资助项目(20090450935);河南省教育厅自然科学研究项目(2008A560015)

摘　　要：结合GB 50011—2010《建筑抗震设计规范》选取与规范各类场地条件相适应的Clough-Penzien地震动随机模型功率谱的谱参数,从多点输入地震角度研究了不同场地、不同设计地震分组情况下单层对称空间刚架结构的动力响应,结果表明:多点非一致地震激励下,即使严格意义上的对称结构也会产生明显的扭转效应,扭转效应大小可采用一致激励下使结构产生同样扭矩的等效偏心率来衡量,且等效偏心率随结构体系的自振周期、平扭周期比、场地条件等因素变化而改变;对于多高层对称结构,多点非一致激励扭转效应的影响主要集中在结构底层附近,这种作用方式类似圣维南局部性原理.A linear structural system that consists of a rigid slab supported by four columns has been studied based on multi-support excitation theory.The appropriate parameters of Clough-Penzien seismic random model,used in the analysis, are given according to the code GB 50011-2010.The results have shown that,spatial variation of ground motions will induce significant torsional response in the case of a symmetric building,where distances between supports are relatively small compared with those for multi-support structural systems.The torsional responses depend strongly on the period and the frequency ratio of the system,on the local soil conditions,and on the time for seismic waves to travel across the base of the system,etc.It has also been found that there is little influence on the top part of a multiple-story symmetric structure subjected to spatially varying multiple excitations.The most influence is focused on the bottom of the structure.Such influence can be well interpreted by Saint Venant Theory.

关 键 词：对称结构 Clough-Penzien地震动随机模型 多点激励 扭转效应 等效偏心率 

分 类 号：TU378.4[建筑科学—结构工程]