跨走滑断层斜拉桥地震响应特性研究  

Seismic response characteristics of cable-stayed bridge across strike-slip faults

作　　者：何康文 张常勇 李怀峰 袁万城[1] 党新志[1] HE Kangwen;ZHANG Changyong;LI Huaifeng;YUAN Wancheng;DANG Xinzhi(State Key Lab of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Shandong Provincial Communications Planning and Design Institute Group Co.,Ltd.,Jinan 250000,China)

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 [2]山东省交通规划设计院集团有限公司,济南250000

出　　处：《振动与冲击》2022年第17期81-92,共12页Journal of Vibration and Shock

基　　金：国家重点研发计划(2019YFE0112300);土木工程防灾国家重点实验室基金(SLDRCE19-B-19);国家自然科学基金(51778471;51978512);山东省交通运输科技计划(2020B74)。

摘　　要：为揭示跨走滑断层斜拉桥的地震响应规律,以一座主跨360 m的斜拉桥为对象,采用OpenSees建立全桥三维非线性动力分析模型,以3组带有永久位移的走滑断层地震动作为输入,重点关注跨断层地震动作用下不同构件的响应特点。通过对比跨断层和近断层斜拉桥的地震响应以研究断层跨越效应的影响,同时分析斜拉桥在不同永久位移幅值和断层跨越角度时的响应规律。研究结果表明:相比于近断层斜拉桥,跨断层斜拉桥的地震响应显著增大,这主要体现于下塔柱横向响应、桥墩的纵向和横向响应、主梁的横向弯矩和扭矩,同时桥塔和主梁在震后还会有很大的残余变形;永久位移幅值和断层跨越角度是影响结构响应的重要因素,当跨越角度不为90°时,桥塔的纵向和扭转响应随永久位移呈增大趋势,桥塔也表现出纵向大残余变形,因此垂直跨越对桥塔一般较为有利,但此时主梁的横向及扭转响应又较非垂直跨越时更大,且对永久位移的大小很敏感;此外,受索、塔、梁之间耦合效应的影响,主梁的竖向响应和索力在非垂直跨越断层时也会发生较大改变。Here,to reveal seismic response law of cable-stayed bridge across strike-slip fault,taking a cable-stayed bridge with main span of 360 m as the object,the software OpenSees was used to establish a 3-D nonlinear dynamic analysis model of the whole bridge,3 groups of strike-slip fault ground motions with permanent displacement were taken as input,response characteristics of different components under across-foult ground motions were focused on.By comparing seismic responses of cable-stayed bridge cross fault and near fault,influences of fault-crossing effect were studied,and response laws of cable-stayed bridge under different permanent displacement amplitudes and fault-crossing angles were analyzed.The results showed that compared with cable-stayed bridge near fault,seismic responses of cable-stayed bridge cross fault increase significantly,especially in transverse response of lower pylon,longitudinal and transverse responses of pier,transverse bending moment and torque of girder,and tower and girder after earthquake can have very large residual deformation;permanent displacement amplitude and fault-crossing angle are important factors affecting structural responses;when fault-crossing angle is not 90°,longitudinal and torsional responses of pylon increase with increase in permanent displacement,and tower also has large longitudinal residual deformation;vertical crossing is generally beneficial to tower,but during this time,transverse and torsional responses of girder are larger than those during non-vertical crossing,and very sensitive to magnitude of permanent displacement;under influences of interaction among cable,tower and girder,vertical response of girder and cable force can also have larger change during crossing fault non-vertically.

关 键 词：跨断层斜拉桥 走滑断层 断层跨越效应 永久位移幅值 断层跨越角度 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]