摘要
浅埋富水煤层长期受覆岩导水裂隙中地下水渗流侵蚀影响,矿井留设隔水煤岩柱及阶段间柱在水岩作用下产生力学损伤劣化。开采活动进一步加快损伤进程,并直接关系到工作面的稳定及安全生产。以陕西榆林锦界煤矿煤岩体为研究对象,制成砂岩-煤-砂岩(S-M-S)组合体,开展不同含水率条件下单轴压缩试验,揭示水岩作用下煤岩组合体的含水率变化规律、力学行为演化特征和声发射损伤规律,基于电镜微观扫描图像,分析水岩作用下组合体内部结构损伤劣化机理。研究结果表明:煤岩组合体吸水速率随着浸水时间的增加不断降低;水岩作用对煤岩组合体抗压强度和弹性模量有明显的劣化效应,组合体弱余强度随含水率增加不断降低,强度损伤速率随着含水率的提高不断加快;组合体的声发射计数和累计计数在水岩作用下衰减明显,并伴随组合体损伤破坏整个过程;水岩作用致使组合体内部结构原生链钝化,裂隙扩展,破裂形式发生明显改变。研究结果可为采动影响下煤岩矿柱水害预测评价提供指导。
Shallow buried water rich coal seams are long-term affected by groundwater seepage erosion in the overlying rock water conducting cracks,and the mechanical damage and deterioration of the water resistant coal rock columns and inter stage columns left in the mine under the action of water and rock occur.Mining activities further accelerate the damage process and directly affect the stability and safety production of the working face.Taking the coal rock mass of Jinjie coal mine in Yulin,Shaanxi Province as the research object,a sandstone-coal-sandstone(S-M-S)combination was developed.We conducted uniaxial compression tests under varying moisture conditions.This characterized moisture absorption,evolution of mechanical behavior and acoustic emission-based damage.Scanning electron microscopy revealed the internal structural degradation mechanisms.The research results indicate that the water absorption rate of coal rock combinations decreases continuously with the increase of immersion time;The water rock interaction has a significant deterioration effect on the compressive strength and elastic modulus of coal rock combinations,and the weak residual strength of the composite decreases continuously with the increase of moisture content,and the rate of strength damage accelerates continuously with the increase of moisture content;Acoustic emissions and cumulative counts were heavily attenuated,accompanying the evolution of damage.The water rock interaction causes the passivation of the primary chain of the internal structure of the combination,the expansion of cracks,and a significant change in the form of fractures.The research results can provide guidance for the prediction and evaluation of water damage in coal rock pillars under the influence of mining.
作者
孙长斌
吴斌斌
杨逾
SUN Changbin;WU Binbin;YANG Yu(China Energy Shendong Coal Group Co.,Ltd.,Ordos,Inner Mongolia 017000;Shendong Coal Branch,China Shenhua Energy Co.,Ltd.,Yulin,Shaanxi 719000;School of Civil Engineering,Liaoning Technical University,Fuxin,Liaoning 123000)
出处
《中国煤炭地质》
2024年第1期30-35,共6页
Coal Geology of China
基金
国家重点研发计划资助项(2018YFC0604705)
国家自然科学基金资助项目(51774167)
辽宁省重点实验室资助项目(LJZS002)。
关键词
矿井水防治
煤岩组合体
力学特性
含水率
声发射
mine water prevention and control
coal-rock combinations
mechanical properties
moisture content
acoustic emission
