低阶煤煤体变形特征及渗流规律实验研究

为获取低阶煤煤体变形特征和渗透率变化规律,以焦坪矿区下石节煤矿3#煤原样为研究对象,利用煤岩体应力-渗流-温度多过程耦合试验系统开展了有效应力、基质收缩以及二者综合作用条件下的煤体变形和渗流实验.研究结果表明:在有效应力逐渐增加的过程中,煤体体积负应变逐渐增大,煤体收缩,渗透率逐渐减小;基质收缩过程中,随着孔压的逐渐下...

Experimental study on deformation characteristics and seepage law of low Rank coal

In order to obtain the deformation characteristics and permeability variation law of low rank coal, the original sample of 3# coal in Xiashijie coal mine in Jiaoping mining area was taken as the research object, the coal deformation and seepage experiments were carried out under the conditions of effective stress, matrix shrinkage and their comprehensive effects by using the multi-process coupling test system of stress-seepage-temperature of coal and rock mass. The results show that in the process of increasing effective stress, the negative volumetric strain of coal increases gradually, the coal shrinkage and permeability decrease gradually; in the process of matrix contraction, with the gradual decrease of pore pressure, the negative volumetric strain of coal increases gradually, and the shrinkage of coal body and permeability increases gradually; under the combined action of the two factors, with the gradual decrease of pore pressure, the negative volume strain of coal body gradually increases, the coal shrinks, and the permeability first decreases and then increases. By comparing with the typical permeability dynamic change model under the condition of equal external forces, the Lu model is more consistent with the experimental data. The experimental results are helpful to predict the dynamic change of coal permeability and guide the development of surface coalbed methane and the prevention and control of coal mine gas.