含水率对弱胶结砂岩力学特征的影响规律  

Influence of water content on mechanical characteristics of weakly cemented sandstone

作　　者：李回贵 李化敏[2] 许国胜 LI Huigui;LI Huamin;XU Guosheng(College of Mining Engineering,Guizhou University of Engineering Science,Bijie 551700,China;School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]贵州工程应用技术学院矿业工程学院,贵州毕节551700 [2]河南理工大学能源科学与工程学院,河南焦作454000

出　　处：《采矿与岩层控制工程学报》2021年第4期56-62,共7页Journal of Mining and Strata Control Engineering

基　　金：贵州省教育厅自然科学基金资助项目(黔教合KY字[2019]166);高层次人才科研启动基金资助项目(院科合字G2018011);毕节市自然科学基金资助项目(毕科联合字G[2019]5号);国家自然科学基金重点资助项目(U1261207)。

摘　　要：为了研究含水率对弱胶结砂岩力学特征的影响规律,以神东矿区大柳塔煤矿岩层中的砂岩为研究对象。首先对弱胶结砂岩进行了XRD,SEM,NMR观测,然后对含水率分别为0,2%,4%和6%的试样在RMT-150C力学试验机下进行单轴压缩试验。研究结果表明:弱胶结砂岩的孔隙率为20.29%,孔隙以中大孔为主,孔隙连通性好;黏土矿物以高岭石和绿泥石为主。含水率对弱胶结砂岩的应力-应变曲线、峰值强度和弹性模量都存在显著影响,峰值强度、弹性模量与含水率存在显著的负相关关系;含水率对峰值应变无显著影响。与干燥试样相比,含水率为2%,4%和6%试样的峰值抗压强度分别降低了20.76%,37.84%,49.01%,弹性模量分别降低了6.25%,31.65%,51.44%;随着含水率的逐渐增加,弱胶结砂岩的塑性逐渐增大。研究成果有助于进一步揭示神东矿区溃水溃沙的机理。To study the influence of water content on the mechanical characteristics of weakly cemented sandstone,the sandstone in Daliuta Coal Mine of Shendong mining area was tested.Firstly,the weakly cemented sandstone was observed by XRD,SEM and NMR,and then uniaxial compression tests were carried out on the samples with the water content of 0,2%,4%and 6%,respectively using the RMT-150C mechanical testing machine.The results show that the porosity of weakly cemented sandstone is 20.29%,and the pores are mainly medium and large pores with good connectivity.The clay minerals are mainly kaolinite and chlorite.Water content has a significant effect on the stress-strain curve,peak strength and elastic modulus of weakly cemented sandstone.There is a significant negative correlation between peak strength,elastic modulus and water content.Water content has no significant effect on peak strain.Compared with the dry samples,the peak compressive strength of the samples with a moisture content of 2%,4%and 6%decreased by 20.76%,37.84%and 49.01%,and the elastic modulus decreased by 6.25%,31.65%and 51.44%respectively.With the increase of water content,the plasticity of weakly cemented sandstone increases gradually.The research results are helpful to further reveal the mechanism of water and sediment break in Shendong mining area.

关 键 词：含水率 弱胶结砂岩 力学特征 微观结构 

分 类 号：TD315[矿业工程—矿井建设]