斜拉桥地震响应与地震动参数相关性分析  

Correlation Between Ground Motion Parameters and Seismic Responses of Cable-stayed Bridges

作　　者：刘亚宾[1] 庞于涛[1] 袁万城[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：《结构工程师》2017年第1期79-84,共6页Structural Engineers

基　　金：土木工程防灾国家重点实验室基金资助项目(SLDRCE14-B-14);国家自然科学基金资助项目(51478339;51278376;91315301);国家科技支撑计划课题(20151BAK17B04)

摘　　要：对于斜拉桥结构而言,目前的研究很少能够给出与地震响应相关性较好的地震动参数,从而使得计算的结构风险并不合理。因而,对地震动参数与斜拉桥地震响应之间的相关性进行了研究。以一座主跨400 m的双塔斜拉桥为例,采用OpenSees建立了非线性的有限元模型,选取195条实测地震记录进行计算,提取了桥塔的剪力、弯矩、曲率、塔顶位移等响应,并对这些响应与地震动参数的相关性进行了分析。结果表明:目前常用的PGA、PGV、反应谱加速度峰值、反应谱速度峰值等参数与斜拉桥地震响应的相关性总体较好,但是仍存在一定的局限性;Housner强度、持续最大速度、Arias强度等参数与斜拉桥地震响应也有较好的相关性,可选为反映斜拉桥响应的地震动强度指标;而PGV/PGA、PGD和位移均方根值等参数与斜拉桥地震响应相关性很差,不宜选为地震动强度指标。For cable-stayed bridge structures, the calculation of structure risk is not reasonable, since ground motion parameters,which have a good correlation with seismic response, are rarely given in current studies. Therefore, the correlation between ground motion parameters and seismic responses of the cable-stayed bridges was studied in this paper. A double-tower cable-stayed bridge with the main span of 400 m was taken an example, a nonlinear finite element model was established in OpenSees. 195 selected motions were applied to the model, and then the responses of various components of the bridge such as the curvature, shear and moment of towers and displacement of top of tower were obtained. Finally, the correlation between ground motion parameters and seismic responses was studied. The results show that conventionally used PGA, PGV, peak spectral acceleration and peak spectral velocity have limitations in representing the seismic responses of the cable-stayed bridges ahhougth they demonstrate good correlation in general, Housner Intensity, Sustained Maximum Velocity and Arias Intensity also demonstrate good correlation with seismic responses of the cable- stayed bridges. These parameters could be selected as intensity measures of ground motions, while PGD, PGV! PGA and Displacement RMS have poor correlation, which are not reasonable to be selected as intensity measures.

关 键 词：斜拉桥 地震响应 地震动参数 相关性 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]