考虑岩层倾角-围压组合效应的岩石强度行为初探  

Preliminary study on the behavior of rock strength considering the combined effects of seam dip and confining pressure

作　　者：罗斌玉 苏辕 刘晓云[1,4] 黄腾达 肖枫亦 刘兰心 李鹏程 LUO Bin-yu;SU Yuan;LIU Xiao-yun;HUANG Teng-da;XIAO Feng-yi;LIU Lan-xin;LI Peng-cheng(College of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan,Hubei 430081,China;Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallergical Mineral Resource,Wuhan University of Science and Technology,Wuhan,Hubei 430081,China;State Key Laboratory of Safety and Health for Metal Mines,Maanshan,Anhui 243000,China;Department of Materials Science,Wuhan University of Science and Technology,Wuhan,Hubei 430081,China)

机构地区：[1]武汉科技大学资源与环境工程学院,湖北武汉430081 [2]武汉科技大学冶金矿产资源高效利用与造块湖北省重点实验室,湖北武汉430081 [3]金属矿山安全与健康国家重点实验室,安徽马鞍山243000 [4]武汉科技大学材料学部,湖北武汉430081

出　　处：《岩土力学》2025年第3期775-788,共14页Rock and Soil Mechanics

基　　金：湖北省自然科学基金青年项目(No.2024AFB281);湖北省应急管理厅安全生产专项资金项目(No.SJZX20220907);武汉市知识创新专项项目(曙光计划项)(No.2022010801020307);金属矿山安全与健康国家重点实验室开放基金(No.2022-JSKSSYS-01)。

摘　　要：研究岩石强度行为的岩层倾角-围压组合效应是揭示充填体约束缓倾斜矿柱强度行为的基础。采用数值模拟代替围压下的岩石倾斜加载试验,研究倾角-围压下岩石剪切破坏规律和强度特征。以红砂岩为研究对象,开展红砂岩单轴和剪切试验,获得红砂岩的基本力学参数。以校核过的红砂岩基本力学参数为基础,开展7种倾角6种围压组合的岩石倾斜加载数值模拟,获取倾角-围压下岩石剪切破坏规律和强度特征。结果显示,随着倾角的增大,剪切带与水平面的倾角越大,且围压越大,剪切带变厚;增大围压能有效降低倾角对岩石强度的影响。然后利用非常规应力圆表征极限状态下岩石应力状态的围压-倾角效应,随着倾角的增大非常规应力圆圆心偏离正应力轴的程度越大,揭示了应力路径的变化规律。基于Mohr-Coulomb强度理论,采用梯度下降算法,将7种倾角6个围压下应力圆上表示极限应力状态的“点”联系起来,求得7种倾角对应的7组强度包络线方程。采用多项式逼近方法,引入倾角维度,将7组“强度包络线”向“强度曲面”拓展,实现从“点”到“线”扩展到“面”的转变,构建包含倾角因素的岩石强度模型。研究结果对揭示矿柱等岩体工程强度的倾角-围压耦合效应具有重要科学意义。Investigating the strength behavior of rock under the combined effects of bedding plane inclination and confining pressure is fundamental to understanding the strength behavior of gently inclined mine pillars constrained by infill.Numerical simulation was employed instead of inclined loading tests under confining pressure to study the shear failure laws and strength characteristics of rock under the combined effects of inclination and confining pressure.Red sandstone was selected as the research object,and uniaxial and shear tests were conducted to obtain its basic mechanical parameters.Based on the calibrated mechanical parameters of red sandstone,numerical simulations of inclined loading of rock were carried out for 7 dip angles and 6 confining pressure combinations,with the average compressive and shear loads of the specimen in the limit state captured using Fish language.The shear failure laws and strength characteristics of rock under the combined effects of dip angle and confining pressure were obtained.The results show that as the inclination angle increases,the angle between the shear band and the horizontal plane becomes larger,and as the confining pressure increases,the shear band thickens;increasing the confining pressure effectively reduces the influence of the inclination angle on rock strength.Then,an unconventional stress circle was used to characterize the stress state of the rock in the limit state and reveal the changing law of the stress path.Based on the Mohr-Coulomb strength theory,the gradient descent algorithm was used to connect the“points”representing the ultimate stress state on the stress circle for 7 inclination angles and 6 confining pressures,yielding 7 sets of strength envelope equations corresponding to the 7 inclination angles.By employing a polynomial approximation method and introducing the dip angle dimension,the 7 sets of“strength envelopes”were extended to a“strength surface”,realizing the transition from“points”to“lines”to“surfaces”and constructing a

关 键 词：强度行为 倾角效应 围压效应 MOHR-COULOMB准则 梯度下降算法 

分 类 号：TU451[建筑科学—岩土工程]