矿井水影响下粗砂岩力学性能变化规律研究  

Study on the change law of mechanical properties of gritstone under the influence of mine water

作　　者：吴宝杨[1,2] 刘康 郭东明[1] Wu Baoyang;Liu Kang;Guo Dongming(School of Mechanics and Civil Engineering,China University of Mining&Technology-Beijing,Beijing 100083,China;State Key Laboratory of Groundwater Protection and Utilization by Coal Mining,National Energy Group,Beijing 102209,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]国家能源集团煤炭开采水资源保护与利用国家重点实验室,北京102209

出　　处：《矿业科学学报》2020年第6期632-637,共6页Journal of Mining Science and Technology

基　　金：国家重点研发计划(2016YFC0501100);国家自然科学基金面上项目(51974315)。

摘　　要：地下水库是矿井地下水处理的有效措施之一,但矿井水对水库坝体力学性能具有弱化效应,威胁着地下水库的安全稳定。因此,有必要开展矿井水作用下岩石力学性能劣化规律研究。本文以灵新煤矿地下水库为背景,通过室内试验研究,分析了矿井水浸泡下粗砂岩力学性能的劣化规律。结果表明:浸泡试件的质量变化与比表面积、填隙物和岩石矿物成分有关。较小水压下,粗砂岩的渗透率呈指数型衰减。但随着水压的进一步增加,堵塞孔隙的颗粒被冲刷,渗透率开始增加;水压越大,渗透率升高幅度越大。随着浸泡时间的增加,岩石抗拉强度存在快速劣化段;之后趋缓,并呈线性劣化趋势。单轴抗压强度呈现先快速减小、后略微增加、再减小的规律。粗砂岩的力学性能劣化是矿井水渗入岩石节理,与填隙物发生水化膨胀以及溶解岩石中部分矿物引起。单轴抗压强度增加阶段与孔隙堵塞引起的孔隙水压力有关。Groundwater reservoir is one of the effective measures for mine groundwater treatment,but mine water has a weakening effect on the mechanical performance of reservoir dam,which threatens the safety and stability of groundwater reservoir.Therefore,it is necessary to carry out the study on the deterioration of rock mechanical properties under the action of mine water.Based on the groundwater reservoir of Lingxin Coal Mine,the deterioration of mechanical properties of gritstone under the effect of mine water immersion was study through laboratory.The test results show that the mass change of the immersed test piece is related to the specific surface area,the interstitial and the rock mineral composition.Under small water pressure,the permeability of gritstone is exponentially attenuated.As the water pressure increases further,the permeability begins to increase as the particles blocking the pores are washed,and the greater the water pressure,the higher the rate of increase of permeability.With the increase of immersion time,the tensile strength of rock has a rapid decrease,then slows down and linearly deteriorates;the uniaxial compressive strength first decreases rapidly,then increases slightly,then decreases.The deterioration of the mechanical properties of gritstone is caused by the infiltration of mine water into the pores of the rock,the ensuing hydration expansion and the dissolution of some minerals in the rock.The increase in uniaxial compressive strength is related to the pore water pressure caused by pore blockage.

关 键 词：矿井水 浸泡 粗砂岩 力学性能 劣化规律 

分 类 号：TD74[矿业工程—矿井通风与安全]