空间小净距交叉隧道动力响应振动台试验研究  

Shaking table tests for dynamic responses of crossing tunnels with small space clearances

作　　者：雷浩 吴红刚 钱建固[1] 赖天文[3] 纪志阳 梁彧 LEI Hao;WU Honggang;QIAN Jiangu;LAI Tianwen;JI Zhiyang;LIANG Yu(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;China Railway Northwest Research Institute Co.,Ltd.,Lanzhou 730070,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]中铁西北科学研究院有限公司,兰州730070 [3]兰州交通大学土木工程学院,兰州730070

出　　处：《振动与冲击》2023年第5期92-100,共9页Journal of Vibration and Shock

基　　金：国家重点研发计划资助项目(2018YFC1504901);中铁九局集团有限公司大连分公司科技开发项目(KJ-2019-01);甘肃省科技计划资助(21JR7RA738)。

摘　　要：为研究空间小净距交叉隧道在地震荷载作用下的动力响应,开展了相似比为1∶50的振动台模型试验,设计并加载了5种工况水平向El-Centro地震波,通过采集的试验数据对隧道动应变响应进行了分析,并对交叉段及非交叉段围岩的加速度响应进行了对比研究,在此基础上使用反应谱理论对其动力特性与地震动之间的关系进行探讨。试验结果表明:上跨隧道的应变峰值均大于下穿隧道,同时上跨隧道的存在及围岩的挤密效应减弱了地震波对于下穿隧道的冲击作用;地震荷载作用下空间交叉隧道的动力响应具有一定的“滞后性”,上跨隧道的震害破坏出现时间较早且更为严重;围岩内部各测点的加速度放大效应都沿高程方向表现出显著的峰值特征,非交叉段的加速度响应在靠近上跨隧道拱顶处最为强烈,而交叉段却出现在靠近下穿隧道拱顶处;坡体各测点位移反应谱的幅值随输入地震波幅值的增大而逐渐增大,且卓越周期也随之增大,即卓越频率逐渐减小;弱震(0.1g)作用下,短周期(0.5~1.5 s)内反应谱曲线具有显著的峰值特征,而强震(0.6g)作用下,长周期(3.0~5.0 s)内反应谱曲线沿高程具有明显的放大效应。Here, to study dynamic responses of crossing tunnels with small space clearances under earthquake load, shaking table model tests with a similitude ratio of 1∶50 were conducted, horizontal El-Centro seismic waves under 5 working conditions were designed and loaded, dynamic strain responses of tunnels were analyzed through the collected test data, and acceleration responses of surrounding rocks in crossing segment and non-crossing segment were studied contrastively. Then relations between tunnel dynamic characteristics and ground motion were explored by using the response spectrum theory. The test results showed that strain peak values of the upper span tunnel are larger than those of the underpass tunnel, and the existence of upper span tunnel and surrounding rock compaction effect weaken impact action of seismic waves on underpass tunnel;dynamic responses of space crossing tunnels under earthquake load have a certain “hysteresis”, and earthquake damage of upper span tunnel appears earlier and more serious;the acceleration amplification effect of each measured point inside surrounding rock reveals a significant peak along elevation direction;the acceleration response of non-crossing segment near arch top of upper span tunnel is the strongest, while that of crossing segment near arch top of underpass tunnel is the strongest;displacement response spectrum amplitude of each measured point on slope body increases with increase in input seismic wave amplitude, and the predominant period also increases, i.e., the predominant frequency decreases gradually;under action of weak earthquake of 0.1g, response spectrum curves within short period of 0.5-1.5 s have significant peak characteristics, while under action of strong earthquake of 0.6g, response spectrum curves within long period of 3.0-5.0 s have obvious amplification effect along elevation direction.

关 键 词：隧道工程 空间交叉隧道 振动台试验 地震响应 反应谱响应 

分 类 号：U45[建筑科学—桥梁与隧道工程]