弱胶结砂岩的物理力学特征及定义

发布时间：2018-02-28 03:08

本文关键词： 弱胶结砂岩矿压显现微观结构物理力学特征　出处：《煤炭科学技术》2017年10期 　论文类型：期刊论文

【摘要】：为给弱胶结砂岩明确的定义,以布尔台煤矿覆岩中弱胶结砂岩为研究对象,采用地面钻孔取心的方法,采集了3种砂岩试样,首先对其成分以及微观结构进行了分析,然后分别对这3组试样进行了单轴压缩、三轴压缩、巴西劈裂试验,分析了弱胶结砂岩的密度、波速、抗拉强度、抗压强度、弹性模量、黏聚力及内摩擦角等参数。试验结果表明:弱胶结砂岩是以石英和长石为骨架颗粒的岩石,胶结物含量小于总含量的30%;弱胶结砂岩颗粒之间的孔隙非常大,主要集中在40~100μm;胶结物非常少,颗粒边界非常清晰;弱胶结砂岩破裂时主要沿颗粒的边界破裂,宏观破裂类型以"I"形为主;弱胶结砂岩的波速(1 200 m/s)和密度(2 200 kg/m3)非常小;抗拉强度(2 MPa)、抗压强度(20MPa)、弹性模量(2 GPa)以及黏聚力(10 MPa)也非常的小。研究成果有助于进一步揭示弱胶结岩层巷道变形大、巷道支护困难、矿压显现剧烈以及地表台阶下沉等现象的内在原因。
[Abstract]:In order to define the weak cemented sandstone, taking the weak cemented sandstone in the overburden rock of Botai coal mine as the research object, three kinds of sandstone samples were collected by the method of surface drilling and coring, and the composition and microstructure of the sandstone samples were analyzed. Then the uniaxial compression, triaxial compression and Brazilian splitting test were carried out to analyze the density, wave velocity, tensile strength, compressive strength and elastic modulus of the weakly cemented sandstone. The experimental results show that the weak cemented sandstone is a rock with quartz and feldspar as the skeleton grain, and the cement content is less than 30% of the total content, and the porosity between the grains of the weak cemented sandstone is very large. It is mainly concentrated at 40 ~ 100 渭 m, the cementation is very few, the grain boundary is very clear, the weak cemented sandstone is mainly broken along the grain boundary, the macroscopic fracture type is mainly "I" shape, the wave velocity of weak cemented sandstone is 1 200 m / s) and the density is 2 200 kg / m 3). The tensile strength, compressive strength, elastic modulus and cohesion are also very small. The research results are helpful to further reveal the large deformation of roadway in weak cemented rock stratum and the difficulty of supporting roadway. The internal causes of the phenomena such as the violent appearance of the rock pressure and the subsidence of the surface steps.
【作者单位】：贵州工程应用技术学院矿业工程学院;河南理工大学能源科学与工程学院;
【基金】：国家自然科学基金煤炭联合基金资助项目(U1261207) 贵州省重点学科矿业工程学科资助项目(ZDXK[2016]13) 贵州省联合基金资助项目(LH字[2016]7051)
【分类号】：TD313

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