三向应力作用下砂岩结构面摩擦特性  

FRICTION CHARACTERISTICS OF SANDSTONE FRACTURE SUBJECT TO THREE-DIMENSIONAL STRESS

作　　者：王者超 赵金萌 乔丽苹 闵忠顺[2] 李晓光[2] WANG Zhechao;ZHAO Jinmeng;QIAO Liping;MIN Zhongshun;LI Xiaoguang(Institute of Deep Engineering and Intelligent Technology,Shenyang 110819,China;Liaohe Oilfield Exploration and Development Research Institute,Panjin 124010,China)

机构地区：[1]东北大学深部工程与智能技术研究院,沈阳110819 [2]辽河油田勘探开发研究院,盘锦124010

出　　处：《工程地质学报》2024年第6期2188-2197,共10页Journal of Engineering Geology

基　　金：辽宁省应用基础研究计划项目(资助号:2022020363-JH2/1013)。

摘　　要：目前,在实验室中研究岩石结构面摩擦性质的实验大多只在受法向应力和剪切应力的受力状态下进行。然而实际工程中的受力状态为真三向应力状态,也就是同时受3个方向不相等的法向应力、侧向应力和剪切应力的受力状态。因此,我们进行了同时受法向应力、侧向应力和剪切应力的双剪结构面摩擦实验,来研究真三向应力下岩石结构面的摩擦特性。岩石结构面摩擦特性包括摩擦系数和摩擦系数降。实验结果分析了侧向应力、剪切速率、剪切位移对摩擦系数、摩擦系数降的影响。分析得到摩擦系数随侧向应力增大而增大,随剪切位移增大而减小;剪切速率1μm·s^(-1)阶跃到10μm·s^(-1),摩擦系数随剪切速率增大而减小,剪切速率10μm·s^(-1)阶跃到100μm·s^(-1),摩擦系数随剪切速率增大而增大;摩擦系数降与剪切位移无关,随侧向应力增加而减小;摩擦系数降在剪切速率10μm·s^(-1)时最大。该方法设计的岩石结构面摩擦实验更符合实际工程受力状态,因此得到的实验结果对了解实际工程结构面摩擦特性更有指导意义。At present,the experiments to study the frictional properties of rock fractures in the laboratory are conducted only under the stress state of normal stress and shear stress.However,the stress state in actual engineering is a true three-dimensional stress state.In other words,it is subjected to unequal normal stress,lateral stress,and shear stress in three directions simultaneously.Therefore,we conducted a double-shear rock fracture friction experiment under normal stress,lateral stress,and shear stress to study the frictional properties of rock fractures under true three-dimensional stress.The friction characteristics of rock fractures mainly include friction coefficient and friction coefficient drop.We analyzed the effects of lateral stress,shear rate,and shear displacement on the friction coefficient and friction coefficient drop of sandstone.The analysis shows that the friction coefficient increases with the increase of lateral stress and decreases with the increase of shear displacement.When the shear rate increases from 1μm·s^(-1)to 10μm·s^(-1),the friction coefficient decreases.When the shear rate increases from 10μm·s^(-1)to 100μm·s^(-1),the friction coefficient increases.The friction coefficient drop is independent of shear displacement and decreases with the increase of lateral stress.The friction coefficient drop is the largest at the shear rate of 10μm·s^(-1).This method designed the rock fracture friction experiment to be more consistent with the actual engineering stress state.Therefore,the experimental results obtained are more instructive for understanding the frictional properties of fractures in actual projects.

关 键 词：结构面摩擦特性 侧向应力 剪切速率 剪切位移 摩擦系数 

分 类 号：TU45[建筑科学—岩土工程]