摘要
为了探究巴库煤矿Ⅵ煤二分层开采顶板覆岩的渗透特性,选取具有代表性的裂隙型软岩(泥岩)和硬岩(中砂岩)两种试样进行了三轴应力状态下的全应力-应变过程渗透性对比试验,得出了主应力差-轴应变变化规律和渗透率-轴应变分布特征,实验结果表明:软、硬岩在主应力差-轴向应变曲线中的特征存在差异,软岩的主应力差随轴向应变呈现线性变化规律,而硬岩则表现出明显的弹性变形、裂隙扩展和裂隙贯通三段性,并基于实验数据给出了主应力差-轴向应变拟合公式;软岩因受泥化影响,在低轴向应变时渗透率随轴向应变表现为明显的波状起伏,在高轴向应变时渗透率-轴向应变曲线波动较小,而硬岩渗透率-轴向应变因受到岩石内部裂隙发育影响较大,随着水压力与渗透率呈现出正态分布趋势,而不同的水压力下渗透率变化更显著。其成果给分析和判断覆岩顶板裂隙突(涌)水理论研究提供了重要的实验依据。
Probing into permeability characteristics of roof overburden on second slice of coal VI in the Barapukuria coalmine, selected representative fractured soft rock （mudstone） and hard rock （medium-grained sandstone） two kinds of samples carried out complete stress-strain process permeability comparative test under triaxial stress state and come out principal stress difference-axial strain variation pattern and permeability-axial strain distribution features. The result has shown that the characteristic performances in principal stress difference-axial strain curves of soft and hard rocks are different. The principal stress difference of soft rock is more obviously varied along with axial strain variation;while of hard rock has shown obvious three stages of elastic deformation, fracture extension and run-through among fractures. Based on tested data come out principal stress difference-axial strain fitting formula. Since impacting from argillation, soft rock is showing an obvious pattern of permeability-axial strain distribution during low axial strain, and showing less fluctuation on permeability-axial strain curves during high axial strain. While permeability-axial strain of hard rock has borne larger impact from rock internal fracture development, along with water pressure and permeability presents normal distribution trend, when under different water pressures the variation of permeability is more obvious. The study has provided important experimental basis for roof overburden fracture water bursting （inrush） theoretical researches.
出处
《中国煤炭地质》
2016年第7期30-33,共4页
Coal Geology of China
基金
"十二五"国家科技支撑计划课题(2012BAK04B04)
国家自然科学基金课题(41402220)
关键词
煤层顶板
水-力耦合
渗透率-轴应变
主应变差-轴应变
实验研究
巴库煤矿
coal roof
hydro-mechanical coupling
permeability-axial strain
principal stress difference-axial strain
experimental study
Barapukuria coalmine
