多点激励下大跨度网架结构的地震反应分析  

Seismic response of long-span grid structure under multi-support excitation

作　　者：赵歆冬[1] 尚慧洁 

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《广西大学学报（自然科学版）》2015年第1期66-72,共7页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然基金资助项目(51008245);陕西省教育厅重点实验室基金(11JS059)

摘　　要：为了研究地震行波效应对大跨度结构的影响,采用时程分析方法对大跨度网架结构进行了多点地震输入下的反应分析,并与一致地震输入结果进行比较,得出了地震行波效应对结构的影响。结果表明:随着视波速的减小,行波效应对结构的影响增大,上部网架超载杆件百分比与行波效应影响系数大于1.2及1.6的网架杆件百分比均增加;行波效应对下部支承柱的影响依据柱子空间位置、内力类型、视波速大小、地震波水平分量输入方向不同而不同。因此,在大跨度网架结构设计中应注意多点地震作用对支座附近杆件的影响,在对支承柱进行多遇地震下的抗震计算时建议对下部边跨各柱弯矩放大1.2倍,跨中各柱弯矩放大1.4倍,各柱轴力放大1.2倍。In order to obtain the influence of travelling wave on long-span structure,the seismic response of long-span grid structure under multi-support excitation was analyzed with the time history analysis method,and the results were compared with those of the structure under uniform earthquake excitation.The influence of traveling earthquake wave on structure can be obtained.The results show that with the decrease of apparent wave velocity,the influence of traveling wave on structure increases,and the percentage of overload rod of both the upper rack and truss whose traveling wave factor over 1.2 and 1.6 all increases.The aforementioned rods are close to the bearings.Therefore,the influence of multi-support earthquake excitation on them should be paid more attention to in the seismic design of the structure.The influence of travelling wave on columns depends on the spatial location of the columns,the types of internal force,the value of apparent wave velocity,and the input direction of horizontal component of seismic wave.In the seismic calculation of columns under frequent earthquake,it is suggested to magnify the axial force of each column 1.2 times,and magnify the bending moment of each column side spans at 1.2 times and the bending moment of each column at mid-spans 1.4 times,respectively earthquake.

关 键 词：大跨度网架结构 地震反应分析 行波效应 一致地震输入 

分 类 号：TU393.3[建筑科学—结构工程]