摘要
以实际工程为背景,在模型试验结果和数值模拟结果验证合理的基础上,通过建立三维数值模型,研究兰州人工波在不同激振方向下坡-隧体系动力响应规律,通过小波包变换从能量和频域角度对衬砌结构动力响应规律进行分析。研究结果表明:水平、竖直面内垂直隧道轴向(X、Z)的地震波在隧道最大埋深处引起较大响应,水平面平行于隧道轴向的地震波(Y)对埋深较浅的洞口处的结构最为不利。频率在0~12.5 Hz范围内的低频波是引起隧道结构响应的主要波段,该频段中竖直向地震波(Z)能量相较于其他方向地震波能量占比最高。地震作用中衬砌结构的存在对坡体内的围岩变形有一定的抑制效应。X、Y向地震波容易引起坡脚附近的围岩发生剪切破坏,Y向地震波对隧道洞口段仰坡的稳定性影响最大;Z向地震波容易造成坡顶附近区域围岩的拉伸破坏,且对隧道拱顶附近产生最不利响应。研究成果对浅埋偏压双联拱隧道的抗震优化设计具有借鉴意义。
Using an actual project as an example,a three-dimensional numerical model was established based on the shaking table test results and numerical simulation results to study the dynamic response law of the slope-tunnel system under different excitation directions of Lanzhou artificial wave.The dynamic response law of the lining structure was analyzed from the perspective of energy and frequency domains using the wavelet packet transform.Results show that the seismic wave perpendicular to the tunnel axis(X,Z)in horizontal and vertical planes will cause a large response at the maximum buried depth of the tunnel,and the seismic wave parallel to the tunnel axis(Y)in the horizontal plane is most unfavorable to the structure.The low-frequency wave in the frequency range of 0-12.5 Hz primarily causes the tunnel response.In this frequency band,the energy of the vertical seismic wave(Z)occupies the highest proportion compared with other seismic waves.The existence of a lining structure has a certain restraining effect on the deformation of surrounding rock under earthquakes.Seismic waves in the X and Y directions can easily cause the shear failure of surrounding rock near the foot of the slope,and the seismic wave in the Y direction has a remarkable influence on the slope of the tunnel portal section.The seismic wave in the Z-direction leads to the tensile failure of surrounding rock near the top of the slope,thereby producing the most adverse response near the tunnel vault.The research results can be used as a reference for the anti-seismic design of shallow-buried double-arch tunnels under unsymmetrical loading.
作者
郭子润
梁庆国
房志群
樊纯坛
陈星宇
孙纬宇
GUO Zirun;LIANG Qingguo;FANG Zhiqun;FAN Chuntan;CHEN Xingyu;SUN Weiyu(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;Poly Changda Engineering Co.,Ltd.,Guangzhou 511431,Guangdong,China)
出处
《地震工程学报》
CSCD
北大核心
2023年第3期742-750,共9页
China Earthquake Engineering Journal
基金
国家自然科学基金(51968041)
中国博士后科学基金(2021M693843)
兰州交通大学“百名青年优秀人才培养计划”。
关键词
黄土联拱隧道
动力响应
小波包变换
激振方向
偏压特征
multi-arch loess tunnel
dynamic response
wavelet packet transform
excitation direction
characteristics of unsymmetrical load
