层状千枚岩隧道地震动力响应不对称性研究  

Research on the Asymmetry of Tunnel Seismic Response in Layered Phyllite

作　　者：赖孝辉 刘洋[1] 周子扬 何川[1] 杨文波[1] 李永林 张文居 LAI Xiao-hui;LIU Yang;ZHOU Zi-yang;HE Chuan;YANG Wen-bo;LI Yong-lin;ZHANG Wen-ju(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Tibetan Area Expressway Co.Ltd.,Chengdu 610031,China)

机构地区：[1]西南交通大学交通隧道教育部重点实验室,成都市610031 [2]四川藏区高速公路有限责任公司,成都市610041

出　　处：《公路》2021年第4期339-348,共10页Highway

基　　金：国家重点研发计划项目,项目编号2016YFC0802210;国家自然科学基金资助项目,项目编号51678499。

摘　　要：为研究不同层理面倾角的炭质千枚岩对隧道结构地震动力响应特征的影响,依托汶马高速卓克基隧道,对现场采集的炭质千枚岩试件进行了轴向压缩试验,并基于有限差分软件FLAC 3D,建立了单轴压缩试验的数值模型,对层状地层基质岩体和层理面的各项力学参数进行了敏感性分析。结合千枚岩试件的轴向压缩试验结果,对地震模拟计算需要的层状岩体各项力学参数进行了标定。隧道的地震计算在FLAC 3D中进行,采用遍布节理模型。结果表明:层理面倾角θ的大小会显著影响千枚岩的力学特性,对于岩体强度,θ为0°时最大,为90°时次之,为60°时最小;对于岩体弹性模量,θ为90°时最大,为0°和60°时较小且相近;倾角为90°及0°时,千枚岩在单轴压缩试验中发生张拉破坏,倾角为60°时发生剪切破坏;在常规三轴压缩试验中均发生剪切破坏。通过对层状千枚岩各项力学参数的敏感性分析可知,在倾角为90°时,可以标定基质岩体的弹性模量E和泊松比μ;在倾角为0°时,可以标定基质岩体的黏聚力c和内摩擦角φ;在倾角为60°时,可以标定层理面的黏聚力cj和内摩擦角φj。层状千枚岩隧道的地震动力响应特征与层理面倾角显著相关;对于层理面倾角为0°和90°的隧道,其地震动力响应有着明显的对称性;对于其他倾角的倾斜地层而言,隧道的地震响应则不对称,不对称的程度与倾角大小有关;该不对称性具有分段特征,分段的倾角角度约在45°~50°之间。In order to study the effect of carbonaceous phyllite with different dip angles on the seismic response of tunnel structure,the axial compression test of carbonaceous phyllite samples collected in the field is carried out based on Zhuokeji Tunnel in the Wenchuan-Maerkang Expressway.Then the numerical model of uniaxial compression test is established in FLAC3 D,and the sensitivity analysis of the mechanical parameters of rock and bedding plane is conducted.Combined with results of axial compression test,the mechanical parameters of layered rock mass for seismic simulation are calibrated.The seismic calculation of the tunnel is carried out in FLAC3 Dwith ubiquitous-joint model.The results show that the bedding plane inclination angleθwill significantly affect the mechanical properties of phyllite.For rock mass strength,θis the largest at 0°,followed by 90°,and the smallest at 60°;for rock mass elastic models,θis the largest at 90°,and is quite small and close in value whenθis 0°and 60°;when the inclination angle is 90°and 0°,the phyllite undergoes tensile failure.Shear failure occur in all the conventional triaxial compression tests;through the sensitivity analysis of the various mechanical parameters of the layered phyllite,it can be known that when the dip angle is 90°,the elastic modulus Eand Poisson’s ratioμof the matrix rock mass can be calibrated;when the inclination angle is 0°,the cohesive force c and internal friction angleφof the matrix rock mass can be calibrated;when the inclination angle is 60°,the cohesive force cjand internal friction angleφjof the bedding surface can be calibrated.The seismic dynamic response characteristics of the layered phyllite tunnel are significantly related to the bedding plane dip angle;for tunnels with bedding plane dip angles of 0°and 90°,the seismic dynamic response has obvious symmetry;for other inclined stratum,the seismic response of the tunnel is asymmetrical and the degree of asymmetry is related to the inclination angle.This asymmetry has the c

关 键 词：隧道工程 地震响应 轴向压缩试验 炭质千枚岩 参数标定 不对称性 

分 类 号：U457.5[建筑科学—桥梁与隧道工程]