空间多点地震作用下桥梁结构碰撞响应振动台试验研究  

Experimental study on seismic pounding response of bridge structures subjected to spatially varying ground motions by shake table test

作　　者：何立翔[1] 任伟新[1,2] 王宁波[1] 汪穹立 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《地震工程与工程振动》2016年第1期24-34,共11页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金资助项目(51278163);澳大利亚研究理事会(ARC)联合项目(LP110200906)~~

摘　　要：地震造成的桥梁上部结构碰撞及落梁破坏在历次大地震中基本都能观察到,以往的研究大多数局限于地震作用下桥梁碰撞响应的数值模拟研究,相关的试验研究还不多。此外,这些研究中也少有考虑空间多维多点地震动作用引起的桥梁上部结构更大的异向振动。本文采用振动台台阵系统,对空间多维多点地震作用下相邻桥梁结构碰撞响应进行试验研究。试验设计制作了几何缩尺比为1∶6的桥梁模型,研究比较了空间多点激励以及摇摆基础与固定基础两种基础形式对试验模型地震碰撞响应的影响。介绍了试验模型的设计制作、传感器布置,给出了试验结果及模型桥梁碰撞破坏情况。试验结果表明,地震动的空间变异性不能忽视,较大的碰撞力会引起桥梁伸缩缝处混凝土严重的局部破坏,相比于固定基础,摇摆基础能有效降低墩的破坏程度,但提高了上部结构的碰撞及落梁风险。Pounding and unseating damages to bridge decks have been commonly observed in all major earth- quakes. Most previous studies were confined to numerical simulation of bridge seismic pounding response, but ex- perimental studies were rare. Moreover, only few studies on the pounding response of adjacent bridge structures have considered spatially varying ground motions which could result in further out-of-phase vibration. An experi- mental study on pounding response of adjacent bridge structures considering spatially varying ground motions are carried out by using a shaking table array system. Two sets of large scale （ 1 ： 6） bridge models are designed and constructed to identify the influences of spatially varying motion and the foundation type including rocking founda- tion and fixed foundation on the pounding response of adjacent bridge structures. This paper describes the experi- mental investigation particularly focusing upon the test model design, constructions, and sensor installation. The experimental results and damages of the bridges observed are also presented in this paper. The results indicate that： （ 1 ） spatial variations of ground motions can＇ t be neglected; （2） large pounding force will cause serious damage of local concrete at the bridge joint ; and （3） compared to fixed foundation, rocking foundation can reduce damages of piers significantly, but will increase the risk of pounding and unseating of superstructures.

关 键 词：振动台试验 碰撞 落梁 多点激励 地震响应 

分 类 号：U442.55[建筑科学—桥梁与隧道工程] P315.9[交通运输工程—道路与铁道工程]