Macroscopic and microscopic mechanical behavior and seepage characteristics of coal under hydro-mechanical coupling  

水-力耦合作用下煤岩宏细观力学行为及渗流特性研究

作　　者：GAO Ming-zhong GAO Zheng YANG Ben-gao XIE Jing WANG Ming-yao HAO Hai-chun WU Yan ZHOU Lang WANG Jing-yu 高明忠;高政;杨本高;谢晶;王明耀;郝海春;吴岩;周浪;王静宇(State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China;State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China;China Railway Engineering Equipment Group Co.,Ltd.,Zhengzhou 451163,China;Northwest Engineering Corporation Limited,Xi’an 710065,China)

机构地区：[1]State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China [2]State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,China [3]State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China [4]China Railway Engineering Equipment Group Co.,Ltd.,Zhengzhou 451163,China [5]Northwest Engineering Corporation Limited,Xi’an 710065,China

出　　处：《Journal of Central South University》2024年第8期2765-2779,共15页中南大学学报（英文版）

基　　金：Project(52225403)supported by the National Natural Science Foundation of China;Project(2023YFF0615401)supported by the National Key Research and Development Program of China;Projects(2023NSFSC0004,2023NSFSC0790)supported by Science and Technology Program of Sichuan Province,China;Project(2021-CMCUKFZD001)supported by the Open Fund of State Key Laboratory of Coal Mining and Clean Utilization,China。

摘　　要：Understanding the physical,mechanical behavior,and seepage characteristics of coal under hydro-mechanical coupling holds significant importance for ensuring the stability of surrounding rock formations and preventing gas outbursts.Scanning electron microscopy,uniaxial tests,and triaxial tests were conducted to comprehensively analyze the macroscopic and microscopic physical and mechanical characteristics of coal under different soaking times.Moreover,by restoring the stress path and water injection conditions of the protective layer indoors,we explored the coal mining dynamic behavior and the evolution of permeability.The results show that water causes the micro-surface of coal to peel off and cracks to expand and develop.With the increase of soaking time,the uniaxial and triaxial strengths were gradually decreased with nonlinear trend,and decreased by 63.31%and 30.95%after soaking for 240 h,respectively.Under different water injection pressure conditions,coal permeability undergoes three stages during the mining loading process and ultimately increases to higher values.The peak stress of coal,the deviatoric stress and strain at the permeability surge point all decrease with increasing water injection pressure.The results of this research can help improve the understanding of the coal mechanical properties and seepage evolution law under hydro-mechanical coupling.了解水-力耦合作用下的煤岩物理力学行为及渗流特征,对矿山围岩稳定性和瓦斯突出防治具有重要意义。通过开展电镜扫描、单轴、三轴等试验,综合分析了不同浸水时长下煤岩的宏细观物理力学特征;并通过在室内还原保护层开采应力路径和注水条件,探究了煤岩采动力学行为与渗流演化规律。结果表明,在水的作用下煤岩微观表面出现剥落现象,微裂隙得到扩展发育;随浸水时长的增加,煤岩单轴和三轴强度呈非线性趋势逐渐降低,在浸水240 h后分别下降63.31%和30.95%;在不同注水压力条件下,煤岩渗透率在开采加载过程中经历三个阶段并最终增大;煤岩峰值应力、渗透率激增点的偏应力及应变均随注水压力的升高而逐渐减小。本研究成果有助于加深对水-力耦合作用下煤岩力学性质和渗流演化规律的理解,为类似条件矿井开采提供指导。

关 键 词：COAL water intrusion mechanical properties PERMEABILITY macro and micro features 

分 类 号：TD315[矿业工程—矿井建设]