不同加载路径条件下软弱夹层泥岩力学响应及变形规律  

Mechanical response and deformation of weak interbedded mudstone under different loading paths

作　　者：张晓悟 徐金海[1,2] 刘智兵[1,2] 孙垒 ZHANG Xiaowu;XU Jinhai;LIU Zhibing;SUN Lei(School of Mines,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory of Coal Resources and Safe Mining(CUMT),Xuzhou 221116,China)

机构地区：[1]中国矿业大学矿业工程学院,江苏徐州221116 [2]煤炭资源与安全开采国家重点实验室(中国矿业大学),江苏徐州221116

出　　处：《采矿与岩层控制工程学报》2021年第4期37-46,共10页Journal of Mining and Strata Control Engineering

基　　金：煤炭资源与安全开采国家重点实验室自主研究课题资助项目(SKLCRSM2020X05)。

摘　　要：原生岩体的整体强度由力学性质最弱的岩层决定。为了研究构造区域软弱夹层泥岩的力学特性及变形规律,设计了4种应力路径下的三轴压缩试验,分析了应力路径和围压对软弱夹层泥岩力学特性及变形规律的影响,提出了应力路径和围压作用下软弱夹层泥岩力学特性及变形规律表征参量。研究结果表明:①软弱夹层泥岩随着围压的增加呈塑性流动、应变强化的特性;②卸压极限承载强度可以表征不同应力路径下卸载过程中的岩石承载能力;③当卸载过程中轴向应力和径向应力均减小时,软弱夹层泥岩的径向应变最大、承载能力最弱;④卸载过程中,软弱夹层泥岩的变形特征符合恶化规律,且弹性模量和泊松比的恶化程度可以分别用一次、二次方程表征。The overall strength of the original rock mass is determined by the rock layer with the weakest mechanical properties.To study the mechanical properties and deformation characteristics of the weak interbedded mudstone in the structural area,triaxial compression experiments with four stress paths were designed,and the influence of the stress path and confining pressure on the mechanical properties and deformation characteristics of the weak interbedded mudstone was analyzed.The results show that:①The weak interbedded mudstone exhibits plastic flow and strain strengthening characteristics as the confining pressure increases.②The ultimate load-bearing strength of unloading can characterize the bearing capacity of the rock during unloading under different stress paths.③When both the axial stress and the radial stress decrease during the unloading process,the weak interbedded mudstone has the largest radial strain and the weakest bearing capacity.④During the unloading process,the deformation characteristics of the weak interbedded mudstone conform to the deterioration law,and the deterioration degree of the elastic modulus and Poisson's ratio can be characterized by the first and second equations,respectively.

关 键 词：软弱夹层 应力路径 力学响应 变形特征 

分 类 号：TD353[矿业工程—矿井建设]