共面断续节理岩体模型抗剪强度及破坏特征分析  

Analysis of Shear Strength and Failure Characteristics of Coplanar Discontinuous Jointed Rock Model

作　　者：任红磊 李鸿亮 胡宝文 REN Hong-lei;LI Hong-liang;HU Bao-wen(College of Water Conservancy and Hydropower,Hebei University of Engineering,Handan 056038,China;Beijing Key Laboratory of Urban Underground Space Engineering,Beijing 100083,China;Hebei Key Laboratory of Intelligent Water Conservancy,Handan 056038,China)

机构地区：[1]河北工程大学水利水电学院,邯郸056038 [2]城市地下空间工程北京市重点实验室,北京100083 [3]河北省智慧水利重点实验室,邯郸056038

出　　处：《科学技术与工程》2021年第20期8629-8637,共9页Science Technology and Engineering

基　　金：河北省自然科学基金(E2019402256);河北省高等学校科学技术研究项目(BJ2019023)。

摘　　要：为探究共面断续节理的几何特征对岩体力学性质的影响,对制作的含节理类岩石材料进行了直剪试验,运用数字图像技术记录全场应变演化过程,并根据室内试验建立颗粒流模型,探究节理连通率和岩桥长度对岩体抗剪强度及裂纹发育的影响。结果表明:各级法向应力下,节理连通率的增加限制翼型应变集中区的形成,进而阻断翼裂纹的发育,使岩桥倾向于拉剪破坏,并会造成岩体模型抗剪强度降低;而节理连通率相同时,岩桥长度的改变则不会对岩体抗剪强度造成明显影响;岩桥长度是改变裂纹发展趋势的主要因素,这是因为岩桥长度的变化会增加或降低相邻节理端部应变集中区的交互影响;最后从能量的角度出发揭示了节理连通率和试样破坏失稳的关系。In order to explore the influence of geometric features of coplanar intermittent jointed rock-mass on the mechanical properties,a direct shear test was conducted on the jointed rock mass and the full-court strain evolution was observed by using digital image technology,what’s more,a particle flow model was established according to laboratory tests.All these above were expected to explore the influence of joint connectivity rate and rock bridge length on the shear strength and failure characteristics of rock mass.The results show the increase in joint connectivity rate restricts the formation of airfoil strain concentration zones,then blocking the development of airfoil cracks,making rock bridges prone to tensile-shear fracture and reducing the shear strength of the model.The change of rock bridge length with the same connectivity rate has no obvious influence on the shear strength of rock mass.The the rock bridge length is the main factor that changes the development trend of cracks,because the change in the length increase or decrease the interactive influence of the strain concentration area at the end of the adjacent joint.Finally,the relationship between joint connectivity and specimen failure and instability is revealed in terms of energy.

关 键 词：断续节理岩体 直剪试验 离散元模型 节理连通率 岩桥长度 数字图像技术 

分 类 号：TU452[建筑科学—岩土工程]