非一致性地震动作用下某长大隧洞动力响应的时空效应初步研究  

Preliminary study on time-space effect of the dynamic response of long tunnel under non-uniform ground motion

作　　者：周永强[1] 盛谦[1,2] 李娜娜 付晓东 ZHOU Yong-qiang;SHENG Qian;LI Na-na;FU Xiao-dong(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;Wuhan Library,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院大学工程科学学院,北京100049 [3]中国科学院武汉文献情报中心,湖北武汉430071

出　　处：《岩土力学》2021年第8期2287-2297,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51809258,No.51679232);中国科学院青年创新促进会(No.2021325)。

摘　　要：为研究非一致性地震动作用下长大隧洞动力响应的时空效应,首先,采用随机地震动合成法生成了能反映某长距离隧洞行波效应、衰减效应等局部场地效应的多条不同地震动时程曲线。通过底部分区域垂直输入的方式,分析了一致性和非一致性地震动作用下某长大隧洞围岩和衬砌的动力响应。在此基础上,通过傅里叶谱、传递函数及相干函数揭示了输入地震与围岩动力响应的频谱相关性。其次,从加速度、位移及相对位移时程等方面研究了不同部位围岩动力响应的空间非一致性。最后,通过分析地震动作用下围岩与结构的动力学特征,研究了围岩与结构地震动力响应的协调性。结果表明,与一致性地震动情况下保持不变相比,非一致性地震动使隧洞沿轴向上相同位置处围岩监测点的传递系数在主频段的变化过程明显不一致;地震动向上传播过程中,沿高程分布各监测点响应和输入地震动的最大相干系数与高程的关系基本符合二次多项式关系,但非一致性地震动输入情况的最大相干系数明显大于一致性地震动输入情况;在非一致地震动输入下,沿隧洞轴向方向上同一个位置的围岩监测点的位移时程虽存在一定的延时现象,但隧洞出口位置处围岩最大位移出现的时间却是早于隧洞进口位置处,而且隧洞围岩监测点加速度峰值、最大位移以及顶底监测点最大相对位移沿隧洞轴向基本呈现两端较大、中间较小的分布趋势;非一致地震动输入下,行波效应还会使隧洞左右两端产生一定的剪切作用。该研究可为地震作用下长大隧洞破坏机制的研究提供整体宏观认识。To study the time-space effect of the dynamic response of a long tunnel under non-uniform ground motions,firstly,a random ground motion synthesis method was used to generate different ground motion time histories,which can reflect local site effects such as traveling wave effects and attenuation effects of long-distance tunnels.Through vertical input,the dynamic responses of the surrounding rock and liner of the long tunnel under the action of uniform and non-uniform ground motions were analyzed.On this basis,through the Fourier spectrum,transfer function and coherence function,the spectral correlation between the input earthquake and the dynamic response of the surrounding rock was revealed.Secondly,the spatial inconsistency of the dynamic response of surrounding rock in different parts was studied in terms of acceleration,displacement,and relative displacement time history.Finally,the coordination of seismic dynamic response of surrounding rock and liner was studied by analyzing their dynamic characteristics under the action of ground motion.The results show that the transmission coefficient of the surrounding rock monitoring points at the same position in the axial direction of the tunnel is inconsistent in the main frequency band under non-uniform ground motion.During the upward propagation of ground motions,the maximum coherence coefficient between the response of each monitoring point along the elevation and the input ground motion has a basically quadratic polynomial correlation with the elevation,but the maximum coherence coefficient of the non-uniform ground motion input is significantly greater than that of the uniform ground motion input.Under non-uniform ground motion input,although there is a certain delay in the displacement time history of the surrounding rock monitoring point at the same location along the tunnel axial direction,the maximum displacement of the surrounding rock at the exit of the tunnel occurs earlier than that at the entrance of the tunnel.Also,the peak acceleration and displaceme

关 键 词：非一致性 长大隧洞 随机地震动 时空效应 相关性 

分 类 号：TU452[建筑科学—岩土工程]