全应力-应变加载过程中砂质泥岩力学与渗透性演化规律研究  

Study on mechanics and permeability evolution of sandy mudstone during full stress-strain loading

作　　者：柴肇云[1] 武小玲[1,2] 刘向御 刘绪 沈玉旭 辛子朋[1] CHAI Zhaoyun;WU Xiaoling;LIU Xiangyu;LIU Xu;SHEN Yuxu;XIN Zipeng(Key Laboratory of In-Situ Property-Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;School of Continuing Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024 [2]太原理工大学继续教育学院,山西太原030024

出　　处：《煤炭学报》2024年第S2期772-781,共10页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51974193,52274091)。

摘　　要：软岩巷道掘进期围岩孔裂隙演化规律及其引起的渗透性变化是突水灾害防治及注浆加固软弱围岩需要解决的基础科学问题之一。借助RockTop多场耦合试验系统对砂质泥岩分别进行了加载方向平行和垂直层理限定围压的应力渗流耦合试验,研究了砂质泥岩全应力应变加载过程的强度特性、破坏形式以及与渗透性间的相互关系,阐明了砂质泥岩全应力应变加载过程中渗流特征演化规律。研究结果表明:含层理砂质泥岩力学强度和渗透性均具有各向异性,平行层理加载强度大于垂直层理加载强度,渗透性则相反;加载方向平行层理岩样破坏模式以单斜剪切和劈裂破坏为主,裂纹环向应变大于轴向应变,表现为体胀扩容。全应力应变曲线分为裂纹压密、线弹性、裂纹稳定扩展、裂纹非稳定扩展和峰后残余强度5个阶段。前三阶段岩样渗透率保持恒定,裂纹非稳定扩展、应力峰值点处亦或峰后残余强度阶段渗透率“突跳”达到峰值,渗透率变化曲线呈“N”型;加载方向垂直层理岩样破坏模式以轴向张拉劈裂和环向剪切滑移复合破坏为主,裂纹轴向应变大于环向应变,表现为轴向压缩。全应力-应变曲线分为稳定变形、非稳定变形和峰后残余强度3个阶段。稳定变形和非稳定变形阶段渗透率保持恒定,峰后残余强度阶段渗透率“突跳”达到峰值,渗透率变化曲线呈“∧”型;渗透率“突跳”为裂隙网络连通激发的渗透率呈几何量级突增现象。The evolution law of surrounding rock pore crack and its permeability change during soft rock roadway excavation is one of the basic scientific problems to be solved in water inrush disaster prevention and grouting reinforcement of weak surrounding rock.The hydraulic coupling tests of sandy mudstone with parallel and vertical bedding limited confining pressure are carried out by Rock Top multi-field coupling test system.The strength characteristics,failure forms and permeability of sandy mudstone under full stress-strain loading process are studied,and the evolution law of permeability in the process of sandy mudstone full stress-strain loading is clarified.The results show that the mechanical strength and permeability of sandy mudstone with bedding are anisotropic,the strength of parallel bedding rock samples in loading direction is higher than that of vertical bedding,but the permeability is opposite.The failure mode of parallel bedding rock samples in loading direction is mainly monoclinic shear and splitting failure,the circumferential strain of the crack is greater than the axial direction,manifested as body expansion.The full stress-strain curve can be divided into five stages:crack compaction,linear elasticity,stable crack growth,unstable crack propagation and post-peak residual strength.The permeability of rock samples in the first three stages remains constant,the permeability“jump”reaches the peak in the stage of unstable crack propagation,the peak of stress or post-peak residual strength,and the permeability change curve is in the shape of“N”.The failure mode of vertical bedding rock samples in the loading direction is mainly composed of axial tension splitting and circumferential shear slip,the axial strain of the crack is greater than the circumferential direction,manifested as axial compression.The full stress-strain curve can be divided into three stages:stable deformation,unstable deformation and post-peak residual strength.The permeability remains constant in the stable and unstable defor

关 键 词：砂质泥岩 层理 破坏模式 渗透率 各向异性 

分 类 号：TD745[矿业工程—矿井通风与安全]