混合体系多塔矮塔斜拉桥推倒分析的适用性研究  

Applicability research on pushover analysis of multi-pylon extradosed cable-stayed bridges with hybrid system

作　　者：周雨洁 宋旭明[1] 邹卓 唐冕[1] ZHOU Yujie;SONG Xuming;ZOU Zhuo;TANG Mian(College of Civil Engineering,Central South University,Changsha 410075,China;Hangzhou Transportation Planning and Design Institute Co.,Ltd.,Hangzhou 310000,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]杭州市交通规划设计研究院有限公司,浙江杭州310000

出　　处：《地震工程与工程振动》2022年第2期181-192,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(52078486)。

摘　　要：为了研究推倒分析求解混合体系矮塔斜拉桥地震响应的适用性,以某混合体系多塔矮塔斜拉桥为工程背景,采用SAP2000建立空间有限元模型,分别对桥梁结构进行弹性和弹塑性推倒分析,探究在多塔矮塔斜拉桥地震分析中传统推倒和模态推倒的优劣及结构在塑性状态下不同计算方法的精确程度。结果表明:在弹性状态下,混合体系矮塔斜拉桥顺桥向和横桥向的地震响应不仅仅由一阶振型控制,高阶振型的影响依旧显著,这导致传统荷载模式求解结果偏差过大,而考虑高阶振型的MPA法在弹性及弹塑性阶段的适用性均较好,且Chopra法与ATC-40法在塑性地震响应求解方面具有良好的统一性。在塑性状态下,ATC-40法和Chopra法得出的纵横向基底剪力与非线性时程偏差较大,建议当采用ATC-40和Chopra法计算混合体系多塔斜拉桥地震下内力响应时需要综合考虑其他模态控制点的影响。In order to study the applicability of push-down analysis to solve the seismic response of a mixed-system low-pylon cable-stayed bridge,a mixed-system multi-pylon cable-stayed bridge was taken as the engineering back⁃ground.SAP2000 was used to establish a spatial finite element model,and the elastic and elastic-plastic push-down analysis of the bridge structure was carried out respectively.The advantages and disadvantages of traditional pushdown and modal push-down in seismic analysis of multi-pylon cable-stayed bridge and the accuracy of different cal⁃culation methods in plastic state are discussed.Results show that in the elastic state,the longitudinal and transverse seismic responses of the mixed system low pylon cable-stayed bridge are not only controlled by the first-order vibra⁃tion modes,but also significantly affected by the higher-order vibration modes,which leads to a large deviation in the solution results of the traditional load modes.However,the applicability of MPA method considering high order modes in elastic and elastic-plastic phases is better,and Chopra method and ATC-40 method have good uniformity in solving plastic seismic response;In the plastic state,the longitudinal and transverse base shear obtained by ATC-40 method and Chopra method deviates greatly from the nonlinear time history.Therefore,it is suggested that the influence of other modal control points should be considered comprehensively when the ATC-40 and Chopra methods are used to calculate the internal force response of the mixed system cable-stayed bridge under earthquake.

关 键 词：矮塔斜拉桥 抗震分析 多模态推倒分析 能力谱法 适用性 

分 类 号：TU022[建筑科学]