三向应力条件下煤体渗透率演化模型研究  

Coal permeability model for gas movement under the three-dimensional stress

作　　者：荣腾龙 周宏伟[1,2] 王路军 任伟光[1] 姬森浩 RONG Tenglong;ZHOU Hongwei;WANG Lujun;REN Weiguang;JI Senhao(School of Mechanics and Civil Engineering,China University of Mining ＆ Technology（Belting）,Beijing 100083,China;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology（Belting）,Beijing 100083,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]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083

出　　处：《煤炭学报》2018年第7期1930-1937,共8页Journal of China Coal Society

基　　金：国家重点研发计划资助项目(2016YFC0600704);国家自然科学基金资助项目(51674266)

摘　　要：为了掌握三向应力条件下煤体渗透率的变化规律,基于捆绑的火柴棍模型,采用弹性理论分析了煤体基质和裂隙变形对渗透率的影响,建立了两种三向应力条件下煤体渗透率的动态演化模型——指数型和立方型,两种模型均突破以往较多模型采用的单轴应变假设,考虑了三向受力条件下煤体的横向应变不为0以及轴向荷载增加的情况。在分别改变轴压围压组合值、气体压力条件下,将理论模型与室内试验结果进行对比分析,结果表明:煤体渗透率随着载荷水平的升高而减小、随着气体压力的升高而增大;两种条件下指数型渗透率模型对煤体渗透率演化过程的定量描述均优于立方型。In order to study the coal permeability under three-dimensional stress condition, the permeability model of exponential form and cubic form were established. The two forms of permeability model were based on bundled match- stick concept. Meanwhile, the influence of matrix and fissure deformation of coal on permeability was analyzed by using the elastic theory. The two forms of model break through the uniaxial strain assumption and contain the fact that the transverse strain is not zero and the axial load is increased under three-dimensional stress condition. Under the condi- tions of changing axial pressure, confining pressure and gas pressure respectively, the theoretical model and laboratory test results were compared and analyzed. The results show that the coal permeability decreases with the increase of load level and the permeability increases with the increase of gas pressure. Under the two conditions, the coal permeability model of exponential form is better than the cubic form in the quantitative description of permeability evolution. The re- sults are of significance to the study of gas migration and extraction.

关 键 词：煤体 渗透率模型 三向应力 裂隙变形 指数型 立方型 

分 类 号：TD712[矿业工程—矿井通风与安全]