岩体结构面各向异性变异系数的尺寸效应研究  

Study of size effect on the anisotropic variation coefficient of rock joints

作　　者：洪陈杰 黄曼 夏才初[1,2] 罗战友 杜时贵[1,2] HONG Chen-jie;HUANG Man;XIA Cai-chu;LUO Zhan-you;DU Shi-gui(School of Civil Engineering,Shaoxing University,Shaoxing,Zhejiang 312000,China;Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province,Shaoxing University,Shaoxing,Zhejiang 312000,China;Zhejiang University of Science and Technology,Hangzhou,Zhejiang 310023,China)

机构地区：[1]绍兴文理学院土木工程学院,浙江绍兴312000 [2]绍兴文理学院浙江省岩石力学与地质灾害重点实验室,浙江绍兴312000 [3]浙江科技学院,浙江杭州310023

出　　处：《岩土力学》2020年第6期2098-2109,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41572299,No.41427802);浙江省自然科学基金(No.LY18D020003);浙江省重点研发计划项目(No.2019C03104)。

摘　　要：岩体结构面的各向异性与尺寸效应特征对其力学性质影响较大,综合考虑两者之间的相互关系对工程岩体稳定性评价具有重要意义。全面分析不同尺度结构面的各向异性分布,提出考虑正交方向三维形貌参数的各向异性变异系数AVC3D。通过渐进覆盖法统计4组天然岩体结构面10种不同采样尺寸的各向异性变异系数及其尺寸效应规律。结果表明:各向异性变异系数均随结构面尺寸增大而减小至定值,其与结构面尺寸具有较好的负对数函数关系;通过归一化处理,各向异性变异系数与结构面尺寸呈现较好的线性函数关系,表明各向异性变异系数具有分形结构,分维数D可以实现其尺寸效应的规律统计。该方法揭示了影响结构面形貌特征方向性变化的最大有效倾角θ^*max和粗糙系数C的增长幅度会随采样尺寸增大趋于稳定的变化机制,体现了当结构面达到各向异性尺寸效应的阈值后,会呈现出稳定的各向异性规律。The anisotropy and size effect of a rock joint have a great influence on its mechanical properties.Considering the relationship between these two features is of great significance to the evaluation of rock mass stability.In this study,in order to investigate the anisotropic distribution of rock joints at different scales,the anisotropic variation coefficient AVC3D is proposed which considers the three-dimensional morphology parameter of orthogonal directions.The AVC3D of four natural joints at ten different sampling sizes are measured based on the progressive coverage statistical method,and the size effect law of the AVC3D is obtained.The conclusions are as follows:the AVC3D reduces to stable with the increase of the rock joint size,and there is a good negative logarithm function relationship between them.The normalized statistical average values of the AVC3D and the normalized size of the rock joints show a good linear function,indicating that the AVC3D has a fractal structure.The fractal dimension D can be achieved using the regular statistics of the size effect of the AVC3D.This method reveals the mechanism that the maximum effective dip angleθ*max and the roughness coefficient C,which affect the directional change of the structural surface features,tend to be more stable with the increase of sampling size.It shows that once the rock joint reaches the threshold of the anisotropic size effect,the stable anisotropy will appear.

关 键 词：岩体结构面 各向异性 尺寸效应 各向异性变异系数AVC3D 分维数 

分 类 号：TU45[建筑科学—岩土工程]