相对法向力下结构面峰值剪切力学性质研究  

Study on Peak Shear Mechanical Properties of Structural Plane Under Relative Normal Force

作　　者：姜政 陈世江 杜广盛 常建平 周琛鸿 杨付领[2] JIANG Zheng;CHEN Shijiang;DU Guangsheng;CHANG Jianping;ZHOU Chenhong;YANG Fuling(School of Mining and Coal,Inner Mongolia University of Science&.Technology,Baotou,Inner Mongolia 014010,China;School of Mining and Mechanical Engineering,Liupanshui Normal University,Liupanshui,Guizhou 553004,China)

机构地区：[1]内蒙古科技大学矿业与煤炭学院,内蒙古包头市014010 [2]六盘水师范学院矿业与机械工程学院,贵贵州六盘水市553004

出　　处：《矿业研究与开发》2024年第4期195-202,共8页Mining Research and Development

基　　金：六盘水师范学院高层次人才引进科研启动专项项目(LPSSYKYJJ202308);贵州省基础科技计划项目(黔科合基础[2017]1168)。

摘　　要：法向力的大小对岩体结构面剪切强度有重要影响,然而对法向力大小的划分还没有一个明确的界限。鉴于此,将法向力与单轴抗压强度的比值定义为一个衡量法向力相对大小的系数,应用PFC2D模拟不同粗糙度下相对法向力结构面剪切试验。结果显示,试验结果与三线段剪切强度理论基本吻合;当相对法向力小于0.06时,抗剪强度增长速率最大,随着相对法向力的增大,抗剪强度增长速率快速减小;当相对法向力在0.06~0.5之间时,抗剪强度增长速率的减小趋势变缓;当相对法向力大于0.5时,抗剪强度增长速率基本平稳。基于三线段剪切强度理论,利用中等法向应力下的抗剪强度公式,得到了剪切作用下黏聚力强化指数和爬坡角弱化指数,通过对比不同材料试件的这两个指数的变化趋势,验证了法向力上下限划分的合理性。The magnitude of the normal force has an important influence on the shear strength of the rock mass discontinuity,but there is no clear boundary for the division of the magnitude of the normal force.In view of this,the ratio of normal force to uniaxial compressive strength was formulated as a coefficient to measure the relative magnitude of normal force,and PFC2D was used to simulate shear experiments on structural planes with relative normal force under different roughness.The results show that the experimental results are basically consistent with the three-line shear strength theory.When the relative normal force is less than 0.06,the growth rate of shear strength is the highest,and the growth rate rapidly decreases with the increase of relative normal force.When the relative normal force is between 0.06-0.5,the decreasing trend of the shear strength growth rate becomes slower.When the relative normal force is greater than 0.5,the growth rate of shear strength is basically stable.Based on the three-line shear strength theory and the shear strength formula under medium normal stress,the cohesion strengthening index and climbing angle weakening index under shear action were obtained.By comparing the change trend of the two indexes under different materials,the rationality of the division of the upper and lower limits of the normal force was verified.

关 键 词：法向力 抗剪强度 结构面 颗粒流 粗糙度 

分 类 号：TD313[矿业工程—矿井建设]