岩石节理接触特征尺寸效应的数值试验研究  

Numerical experiments on scale effects of contact characteristics of rock joints

作　　者：龚耕 李升连 张国华 熊峰[1] 唐志成 GONG Geng;LI Shenglian;ZHANG Guohua;XIONG Feng;TANG Zhicheng(Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;Yunnan infrastructure investment Co.,Ltd.,Kunming 650032,China;Key Laboratory of Geological Survey and Evaluation of Ministry of Education,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]云南建设基础设施投资股份有限公司,云南昆明650032 [3]地质探测与评估教育部重点实验室,湖北武汉430074

出　　处：《岩土工程学报》2024年第7期1481-1490,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金面上项目(42177165,42277173);地质探测与评估教育部重点实验室主任基金项目(GLAB2023ZR03)。

摘　　要：为探究岩石节理接触特征尺寸效应,采用自仿射分形方法构建系列尺寸数值模型,利用离散弹塑性计算方法求解闭合变形,定量分析节理接触特征尺寸效应规律,并探究不同岩性和粗糙度对其尺寸效应的影响差异。自仿射分形方法构建的岩石节理其粗糙程度随尺寸增加逐渐变小,接触面积比和组合形貌微凸体参数之间具有关联,接触面积比的尺寸效应可归因于组合形貌微凸体参数ηR的尺寸变化。岩石节理尺寸越大,闭合变形引起的塑性部分占比越多。塑性变形对接触面积比尺寸效应具有弱化作用,对闭合变形尺寸效应具有强化作用,硬岩节理的接触特征尺寸效应强于软岩节理,其接触特征代表性长度也更大。岩石节理的粗糙度对其闭合变形和接触面积比的尺寸效应具有相反的效果。To investigate the scale effects of contact characteristics in rock joints,a series of numerical models for joint sets with different sizes are generated using the self-affine fractal enlargement method.Subsequently,the normal contact problems are solved using a discrete elastic-plastic normal closure model.The contact characteristics in rock joints are analyzed quantitatively,and the effects of lithology and roughness of rock joints are also investigated.The roughness of the self-affine enlarged rock joints decreases with size.Moreover,there is a close correlation between the contact area ratio and the asperity parameters of the composite topography.The scale effects of the contact area ratio can be attributed to the variation of the combined asperity parameters of the composite topography ηR with size.Additionally,the plastic components of normal closures increase with the joint size.The plastic deformation has weakening effects on the size effects of the contact area ratio,but strengthening effects on the size effects of closure deformation.The hard rock joints have a stronger scale effect of contact characteristics than the soft rock joints,and the representative lengths are also longer.The roughness of the rock joints has a contrary effect on the scale effects of the normal closure deformation and contact area ratio.

关 键 词：岩石节理 自仿射分形 尺寸效应 接触特征 

分 类 号：TU451[建筑科学—岩土工程]