单向应力下类岩石试件预制浅裂隙发育规律及破坏特征分析  

Development Law and Failure Characteristics of Prefabricated Shallow Fractures in Rock-Like Specimens Under Unidirectional Stress

作　　者：陈龙[1] 李利 孔德中[1] 崔道品[1] 刘勤志 CHEN Long;LI Li;KONG Dezhong;CUI Daopin;LIU Qinzhi(College of mining,Guizhou University,Guiyang,Guizhou 550025,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025

出　　处：《矿业研究与开发》2024年第5期135-141,共7页Mining Research and Development

基　　金：国家自然科学基金地区项目(52064005,52164002,52164005);贵州省科技支撑计划项目(黔科合支撑[2021]一般399);贵州大学实验室开放项目(SYSKF2023-056,SYSKF2023-063,SYSKF2023-064);贵州省高等学校科技创新团队项目(黔教技[2023]055号);贵州省基础研究(自然科学)项目(黔科合基础-ZK[2024]重点022)。

摘　　要：我国西南煤矿在开采过程中覆岩裂隙发育显著,开采扰动较强,围岩控制难度较大。为研究含裂隙岩石破坏机理,改善西南矿区围岩控制效果,采用单轴压缩试验结合DIC技术研究了裂隙倾角、裂隙数量等对类岩石试件力学特性、表面变形场、裂隙扩展路径的影响。结果表明:裂隙倾角由0°和90°变化至45°的过程中,岩石单轴抗压强度降低程度分别由12.47%和16.66%增至28.83%,单裂隙试件、双裂隙试件、三裂隙试件的平均峰值强度分别为完整试件的80.24%、69.07%、56.94%,单裂隙类岩石试件在单向应力下,常沿裂隙端翼出现裂纹扩展,多裂隙类岩石试件则出现与加载方向平行的裂隙。当单裂隙试件裂隙倾角为45°和60°时,试件最大主应变超过完整试件;在多裂隙试件中,仅双横向裂隙试件有此现象。此研究结果可为控制我国西南煤矿围岩稳定性提供理论依据。In the process of coal mining in Southwest China,the fracture development of overlying rock is significant,the mining disturbance is strong,and the control of surrounding rock is difficult.In order to study the failure mechanism of fractured rock and improve the control effect of surrounding rock in southwest mining area,uniaxial compression tests combined with DIC technology were used to study the influences of fracture dip angle and fracture number on the mechanical properties,surface deformation field and fracture propagation path of rock-like specimens.The results show that during the change period of fracture dip angle from 0°and 90°to 45°,the decrease degree of uniaxial compressive strength of rock increases from 12.47%and 16.66%to 28.83%respectively.The average peak strength of single-fracture specimen,double-fracture specimen and three-fracture specimen is 80.24%,69.07%and 56.94%of the peak strength of complete specimen.Single-fracture specimens often exhibit cracks propagation along the fracture tip under unidirectional stress,while multi-fracture specimens exhibit cracks parallel to the loading direction.When the fracture dip angle of single-fracture specimens is 45°and 60°,the maximum principal strain of the specimens exceeds that of the complete specimens.In multi-fracture specimens,only double-transverse-fracture specimens exhibit this phenomenon.This research result can provide a theoretical basis for controlling the stability of surrounding rocks in coal mines in Southwest China.

关 键 词：单向应力 裂隙演化 预制裂隙 破坏特征 最大主应变 

分 类 号：TD315[矿业工程—矿井建设]