含隧道场地地震动放大效应的深度变化规律研究  

Study on variation law of ground motion amplification effects along depth in tunnel site

作　　者：兰景岩 蔡金豆[1] 吴连斌 史庆旗 LAN Jing-yan;CAI Jin-dou;WU Lian-bin;SHI Qing-qi(College of Civil Engineering and Architecture,Guilin University of Technology,Guilin,Guangxi 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《岩土力学》2022年第8期2083-2091,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52168067);广西自然科学基金(No.2021GXNSFAA220017);广西高等学校千名中青年骨干教师培育计划(No.2020);广西研究生教育创新计划项目(No.YCSW2022311)。

摘　　要：以剑桥大学工程系完成的含圆形隧道的动力离心模型试验结果为基础数据,在80g重力加速度条件下,从模型基底处由弱至强输入4种地震波EQ1~EQ4,利用在叠环式模型箱内不同位置布设加速度传感器,获取了不同层位深度处隧道列的加速度时程记录,运用考虑相消干涉的传统谱比法,分析研究了地震作用下含隧道的场地放大效应随深度变化规律。研究结果表明:在EQ1~EQ4下各振型的地震动放大系数随深度变化曲线从基底到地表大部分呈现一个先减小后增大的现象;并统计到高阶振型地震动放大系数数值大于一阶振型的概率为18.3%,振型越高,概率越大;近地表处地震动放大系数的最大值主要分布在4.20~8.63 Hz的中部频段上,而不是出现在低频段上。Based on the results of dynamic centrifugal model test with circular tunnel completed by the Engineering Department of Cambridge University,four different kinds of seismic waves EQ1-EQ4 from weak to strong were input at the base of the model under the condition of 80g gravity acceleration,and acceleration sensors were arranged at different positions in the laminated model box to measure the acceleration time history at different depths along the tunnel location.Using the traditional spectral ratio method considering destructive interference,the variation law of site amplification effect with depth under earthquake was analyzed and studied.The results show that under EQ1-EQ4,the ground motion amplification factor of each vibration mode decreases first and then increases from the base to the surface.According to the statistics,the probability that the value of ground motion amplification factor of high-order mode is larger than the first-order mode is 18.3%.The higher the mode,the greater the probability.The maximum value of ground motion amplification factor near the surface is mainly distributed in the middle frequency band of 4.20 –8.63 Hz,rather than in the low frequency band.

关 键 词：动力离心模型试验 隧道 中硬土 传统谱比法 场地放大效应 

分 类 号：TU93[建筑科学—结构工程]