岩体结构面两级粗糙度各向异性特征量化表征的间距效应研究  

STUDY ON SAMPLING INTERVAL EFFECT IN QUANTITATIVE CHARACTERIZATION OF TWO-ORDER ROUGHNESS ANISOTROPY FEATURES OF ROCK STRUCTURAL PLAN

作　　者：任昱行 许文涛 张诗淮 马晓冬 REN Yuhang;XU Wentao;ZHANG Shihuai;MA Xiaodong(School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]南京大学,地球科学与工程学院,南京210023 [2]中国矿业大学,深部岩土力学与地下工程国家重点实验室,徐州221116 [3]中国科学技术大学,地球和空间科学学院,合肥230026

出　　处：《工程地质学报》2024年第6期2072-2084,共13页Journal of Engineering Geology

基　　金：国家自然科学基金项目(资助号:42402288);江苏省自然科学基金项目(资助号:BK20241206);中国博士后科学基金项目(资助号:GZB20230298);深部岩土力学与地下工程国家重点实验室开放基金项目(资助号:SKLGDUEK2213)。

摘　　要：结构面宏观起伏体和微凸体的三维形貌特征会直接影响岩石的剪切力学性质,认识不同采样间距下两级形貌粗糙度的各向异性特征,对准确把握岩体剪切破坏机理具有重要意义。鉴于目前对两级形貌粗糙度各向异性特征的研究较少,基于界限采样间距形貌分级原理获取两级粗糙度参数,提出了考虑粗糙度优势方向和劣势方向的各向异性系数RAC^(3D),通过点云稀疏方法统计了不同采样间距下3组样品的两级形貌粗糙度各向异性系数。结果表明:微凸体粗糙度各向异性系数随采样间距扩大先逐渐增大然后减小,与采样间距有较好的二次多项式拟合关系;宏观起伏体在小采样间距下粗糙度各向异性系数的间距效应不明显,当间距超过界限采样间距之后,各向异性系数迅速衰减与采样间距呈负指数乘幂函数关系。通过对结构面两级形貌几何结构分析发现,随采样间距增大,优势方向和劣势方向粗糙度衰减的快慢是影响两级形貌各向异性系数变化的主要因素。粗糙度各向异性特征越明显的结构面受采样间距变化的影响越大。本文为研究结构面两级形貌粗糙度各向异性特征的间距效应规律提供参考。Three-dimensional morphology of the macroscopic undulation component and asperities of rock joints can directly affect the shear mechanical properties.Understanding the two-order roughness anisotropy features of joint surfaces at different sampling intervals is important to recognize the shear failure mechanism of rock mass.In view of the fact that there are few studies on the anisotropy characteristics of two-order roughness of rock joints at present,the two-order roughness components based on limit sampling interval morphological classification method are obtained,and the anisotropy coefficient RAC ^(3D) considering the dominant and disadvantageous directions of roughness is proposed.The anisotropy coefficients of the two-order roughness of three joint samples at different sampling intervals based on point cloud sparse method are calculated.The results show that the anisotropy coefficient of the second-order roughness first increases and then rapidly decreases with sampling interval increase,and has a good quadratic polynomial fitting relationship with sampling interval.The interval effect of roughness anisotropy coefficients on first-order roughness is not obvious at a small sampling interval.When the interval exceeds the limit sampling interval,anisotropy coefficient decays rapidly and has a negative numerical power function with the sampling interval.The analysis of the two-order roughness morphology geometry of the rock joints shows that the speed of the roughness attenuation rate in the advantage and weakness directions with the sampling interval increase is the key factor that causes the variation of the anisotropy coefficients of two-order roughness.The more obvious the anisotropy characteristics of joint surfaces roughness are,the more influenced they are by the variation of sampling interval.This paper can provide a reference for the study of the sampling interval effect on the two-order roughness anisotropic features of rock joints.

关 键 词：结构面 两级粗糙度 宏观起伏体 粗糙度各向异性系数 间距效应 

分 类 号：TU45[建筑科学—岩土工程]