含预制双裂隙砂岩亚失稳阶段力学特性及裂纹演化规律试验研究  

Experimental study on the mechanical properties and crack evolution patterns of sandstone with prefabricated double fractures in sub-instability stage

作　　者：崔义 蒲源源 陈紫阳 孟历德仁 陈结[1,3] CUI Yi;PU Yuanyuan;CHEN Ziyang;MENGLI Deren;CHEN Jie(School of Resources and Safety Engineering,Chongqing University,Chongqing 400030,China;Zhalainuoer Coal Industry Co.,Ltd.,Hulunbeir Inner Mongolia 021410,China;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400030,China)

机构地区：[1]重庆大学资源与安全学院,重庆400030 [2]扎赉诺尔煤业有限责任公司,内蒙古呼伦贝尔021410 [3]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400030

出　　处：《矿业科学学报》2025年第2期194-202,共9页Journal of Mining Science and Technology

基　　金：国家重点研发计划(2021YFC2900400);国家自然科学基金(52104077);中央高校基础科研经费项目(2022CDJXY-009);华能集团总部科技项目(HNKJ22-HF122)。

摘　　要：为研究岩桥长度对预制双裂隙砂岩亚失稳阶段的影响,开展含预制双裂隙砂岩单轴压缩试验,并利用数字图像技术(DIC)实时监测试样表面位移,分析不同砂岩试样在亚失稳阶段下的力学特性及表面裂纹扩展特征。结果表明:相比完整岩体,裂隙砂岩会出现应力降现象,在首次应力降后进入亚失稳阶段;随岩桥长度的增加,亚失稳阶段的持续时间与试样破坏全周期时间比逐渐减小,亚失稳阶段的应力变化与峰值应力比也逐渐减小,次生裂隙部位崩解且崩解面积逐渐增大。As coal mining in China gradually shifts from shallow to deep layers,the impact of mining disturbances increases,making it more difficult to control the development of surrounding rock fractures.This study aims to investigate the effect of rock bridge length on the sub-instability stage of sandstone with prefabricated double fractures through uniaxial compression tests on sandstone samples with prefabricated double fractures.DIC technology was used to monitor surface displacements in real time.We analyzed the mechanical properties and surface crack propagation characteristics of different sand-stone samples in the sub-instability state.Results show that:Compared with intact rock,fissured sand-stone exhibits stress drop,entering the sub-instability stage after the first stress drop.As the rock bridge length increases,the ratio between the sub-instability stage duration and the total failure cycle time shows gradual decrease.The ratio between the stress change during the sub-instability stage and the peak stress gradually decreases.Rock bridge length mainly affects the propagation of secondary cracks on the surface during the sub-instability stage.Increasing rock bridge length leads to local disin-tegration in secondary cracks,and the disintegration area gradually increases.This study offers refer-ences to the monitoring and early warning of instability and failure of surrounding rock in coal mines.

关 键 词：岩桥 双预制裂隙 亚失稳阶段 数字图像技术 

分 类 号：TD411[矿业工程—矿山机电]