层状岩体中巷道底板应力分布规律及损伤破坏特征  

Stress distribution and damage characteristics of roadway floor in layered rock mass

作　　者：杨仁树[1,2] 朱晔 李永亮[1] 李炜煜[1] YANG Renshu;ZHU Ye;LI Yongliang;LI Weiyu(State Key Laboratory for Geomechanics and Deep Underground Enginecring,School of Mechanics and Civil Engineering,School of Energy and Mining Engincering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Civil and Resource Enginecring,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室力学与建筑工程学院能源与矿业学院,北京100083 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《中国矿业大学学报》2020年第4期615-626,645,共13页Journal of China University of Mining & Technology

基　　金：国家自然科学基金青年基金项目(51804310);国家自然科学基金项目(51134025);国家重点研发计划项目(2016YFC0600903)。

摘　　要：为了研究开挖巷道后层状岩体中底板的卸荷力学响应,将底板视作横观各向同性体,采用力学分析和数值模拟相结合的方法,对底板应力分布规律与损伤破坏特征进行研究.结果表明:1)与均质各向同性解相比,横观各向同性解更客观地反映出巷道开挖后底板出现卸荷且两侧围岩呈应力集中的应力分布状态;2)底板应力分布随垂直和水平方向力学属性的不同而呈现出差异性;3)底板层状复合结构造成应力发生畸变,软弱岩层的柔性缓冲垫层作用使应力传递变得更为平缓;4)底板岩体达到损伤阈值即发生张拉或者滑移破坏,损伤阈值受垂直卸荷系数、水平卸荷系数、侧压系数、裂隙面倾角等多个因素综合影响.理论和数值计算获得的底板损伤破坏深度及损伤区分布特征基本一致,解析解很好地反映了底板的实际应力状态.To study the unloading mechanical response of the floor after excavation of the roadway in the layered rock mass,the floor was regarded as a transverse isotropic body.The mechanical analysis and numerical simulation were used to study the stress distribution law and damage characteristics of the floor.The results show that:1)Compared with the homogeneous isotropic body,the transversely isotropic body more objectively reflects the stress state after excavation of the roadway,that is,the roadway floor is unloaded,and the surrounding rock is stress-concentrated.2)The stress distribution of floor changes with the difference mechanical properties in vertical and horizontal.3)The layered composite structure of floor causes stress distortion,and the flexible cushion effect of the weak rock layer makes the stress propagation become milder.4)When the floor rock mass reaches the damage threshold,it will be tensioned or slipped along the fracture surface.The damage threshold is affected by multiple factors such as vertical unloading coefficient,horizontal unloading coefficient,lateral pressure coefficient and fracture surface inclination angle.The damage depth and the distribution characteristics of the damage zone obtained by theoretical calculation are basically the same as those obtained by numerical calculation.The analytical solution can reflect the true stress state of floor well.

关 键 词：层状底板 横观各向同性体 力学模型 数值计算 破坏深度 损伤区分布 

分 类 号：TD353[矿业工程—矿井建设]