矿业科学学报2025，Vol.10Issue(2)：194-202,9.DOI:10.19606/j.cnki.jmst.2025006
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
摘要
Abstract
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 frac-tures.This study aims to investigate the effect of rock bridge length on the sub-instability stage of sand-stone 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Key words
rock bridge length/prefabricated double fractures/sub-instability stage/digital image technology分类
矿山工程引用本文复制引用
崔义,蒲源源,陈紫阳,孟历德仁,陈结..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[J].矿业科学学报,2025,10(2):194-202,9.基金项目
国家重点研发计划(2021YFC2900400) （2021YFC2900400）
国家自然科学基金(52104077) （52104077）
中央高校基础科研经费项目(2022CDJXY-009) （2022CDJXY-009）
华能集团总部科技项目(HNKJ22-HF122) （HNKJ22-HF122）
