大跨度斜拉桥随机有限元抖振概率评价  

Buffeting Assessment on Long-Span Cable-Stayed Bridge Based on Stochastic FEM

作　　者：赵林[1] 葛耀君[1] 项海帆[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《同济大学学报（自然科学版）》2008年第9期1176-1181,共6页Journal of Tongji University:Natural Science

基　　金：国家自然科学基金青年基金资助项目(50408035);国家自然科学基金重点资助项目(90715039);国家"八六三"高技术研究发展计划资助项目(2006AA11Z108)

摘　　要：依据桥梁风致抖振分析理论和随机有限元方法,在结构振型叠加算法中,融入基于参数敏感性分析技术的验算点搜索算法,求解出大跨度斜拉桥复杂结构体系中考虑气动荷载、材料属性和截面特性等随机性因素的风致抖振可靠度指标.以东海大桥为算例,首先进行工程场地平均风极值风速预测和空间脉动风场随机模拟,采用桥梁断面气动力参数识别结果确定结构气动力荷载.在改善结构荷载输入精度前提下,对其中多个关键环节———导纳函数、重现期、多种结构随机性进行参数分析,实现了大跨度斜拉桥抖振失效评价的过程分析,并从中得出相关结论.Based on the present buffeting theories and stochastic FEM assessment methods, failure index about complex structures, such as long-span cable-stayed bridges, is calculated by means of combining parameter sensitivity analysis with advanced first-order reliability method （AFORM） in the light of mode shape iteration method. In the above process, several stochastic factors, such as aerodynamic loading, material properties and geometry sizes, are considered. Then the general methodology of buffeting probability assessment for long-span bridges is proposed. Finally, the buffeting assessment of East Sea Bridge, a long-span cable-stayed bridge with 420 m mid-span, is selected as a numerical example and a series of steps, including mean wind prediction, stochastic wind simulation are taken. And an analysis is made of the effects about aerodynamic admittance function, return period and several stochastic factors on buffeting failure probability for long-span bridges.

关 键 词：斜拉桥 风致抖振 随机有限元 敏感性分析 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]