不同开度节理大理岩破裂过程与断裂面形貌特征研究  

STUDY ON FAILURE PROCESS AND FRACTURE SURFACE MORPHOLOGY CHARACTERISTICS OF MARBLE WITH DIFFERENT JOINT APERTURES

作　　者：黄丹 肖子龙 汤文[1] 金清平[2] HUANG Dan;XIAO Zilong;TANG Wen;JIN Qingping(School of Automotive and Traffic Engineering,Wuhan University of Science and Technology,Wuhan 430065,China;School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China)

机构地区：[1]武汉科技大学汽车与交通工程学院,武汉430065 [2]武汉科技大学城市建设学院,武汉430065

出　　处：《工程地质学报》2024年第6期2239-2249,共11页Journal of Engineering Geology

基　　金：湖北省教育厅科学研究计划青年项目(资助号:Q20221104);湖北省交通运输厅2023年科技计划(资助号:2023-121-1-21)。

摘　　要：考虑节理对岩体的力学行为有着重要的影响以及破裂面形貌特征差异,进行不同开度节理大理岩岩样单轴压缩试验。借助高速摄像机、PFC^(3D)颗粒流软件和三维激光扫描等软件与仪器,分析节理对岩体力学性能及破坏特征的影响,研究岩体从起裂到破坏的宏细观破坏特征。扫描断裂面形貌数据并采用形貌曲线一阶均方根计算断裂面的JRC值,探究不同类型断裂面的形貌特征。结果表明:岩体的力学性能与节理开度有关。在单轴压缩条件下,完整试件中的拉伸裂纹由试件中部向两端发育,剪切裂纹主要由试件端部向中部发育,呈现剪切为主、拉伸为辅的模式破坏;预制裂隙试件由于节理尖端应力集中,微裂纹在节理尖端萌生并向端部发育,形成拉伸翼裂纹和剪切翼裂纹并贯通,呈现出拉剪混合破坏特性。通过断裂面的形貌特征分析得出在单轴压缩条件下,拉伸断裂面JRC在7~10之间,剪切断裂面JRC在11~14之间。拉伸断裂面曲线特征值分布差别较大,呈现出边缘高中间低的特性。Considering the important influence of joints on the mechanical behavior of rock mass and the difference in fracture surface morphology,uniaxial compression tests of marble specimens with different openings were carried out.With the help of a high-speed camera,PFC 3D particle flow software,and three-dimensional laser scanning software and instruments,the influence of joints on the mechanical properties and failure characteristics of rock mass is analyzed,and the macro and micro failure characteristics of rock mass from crack initiation to failure are studied.The fracture surface morphology data were scanned,and the JRC value of the fracture surface was calculated by using the first-order root mean square of the morphology curve to explore the morphology characteristics of different types of fracture surfaces.The results show that the mechanical properties of rock mass are related to the joint opening.Under the condition of uniaxial compression,the tensile cracks in the complete specimen develop from the middle of the specimen to both ends,and the shear cracks mainly develop from the end of the specimen to the middle,showing a mode of shear-based and tensile-assisted failure.Due to the stress concentration at the joint tip of the prefabricated joint specimen,micro-cracks initiate at the joint tip and develop towards the end,forming tensile wing cracks and shear wing cracks and penetrating,showing a tensile-shear mixed failure mode.Through the analysis of the morphological characteristics of the fracture surface,it is concluded that under uniaxial compression,the tensile fracture surface JRC is between 7 and 10,and the shear fracture surface JRC is between 11 and 14.The distribution of characteristic values of tensile fracture surface curves is quite different,showing the characteristics of high edges and low middle.

关 键 词：岩石力学 预制裂隙 裂纹扩展与破坏 颗粒流程序 粗糙度曲线 

分 类 号：P642.3[天文地球—工程地质学]