深部放顶煤开采下煤层应力场-渗流场耦合演化特征  

The coupled stress-seepage behavior of bottom coal in deep top-coal caving method

作　　者：赵洪宝[1,2] 荆士杰 李作泉 刘超 张鸿伟 侯玮 李新潮 ZHAO Hongbao;JING Shijie;LI Zuoquan;LIU Chao;ZHANG Hongwei;HOU Wei;LI Xinchao(School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;New Energy Development and Disaster Prevention Research Center,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Mining and Geomatics Engineering,Hebei University of Engineering,Handan 056038,China;Handan Niuerzhuang Mining Co.,Ltd.,Handan 056201,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]中国矿业大学(北京)新能源开发与灾害防治研究中心,北京100083 [3]中国矿业大学力学与土木工程学院,江苏徐州221116 [4]河北工程大学矿业与测绘工程学院,河北邯郸056038 [5]邯郸市牛儿庄采矿有限公司,河北邯郸056201

出　　处：《采矿与岩层控制工程学报》2024年第5期91-103,共13页Journal of Mining and Strata Control Engineering

基　　金：中国矿业大学(北京)基本科研业务费-博士研究生拔尖创新人才培育基金资助项目(BBJ2023004);国家自然科学基金资助项目(51474220)。

摘　　要：为了研究高应力区煤体在放顶煤开采方式下的应力场-渗流场的耦合演化规律,以横观各向同性下的火柴棍模型为基础,构建了由煤基质和裂隙组成的弹性系统,建立了三向应力条件下煤体渗透率演化规律模型,并结合采场应力场空间分布规律,构建煤层增透率空间分布模型。在改变围压、轴压和气体压力的条件下,将渗透率模型和室内试验结果对比,并将增透率空间分布模型与顺层抽采钻场的瓦斯抽采相关数据对比分析,结果表明:煤体渗透率随载荷与气体压力的增加而减小,并呈指数型;渗透率模型可以较好地定量描述煤体渗透率在加卸载条件下的变化,与多组试验数据的相关系数和拟合优度均大于0.9;增透率空间分布随距离增大呈指数下降,可分成4个阶段:原岩稳定阶段、增压降低阶段、卸压增加阶段、破坏稳定阶段;根据增透率模型和现场数据对比,煤层在卸压增加阶段和破坏稳定阶段处于增透状态,煤层增透范围Lr=55.62 m;煤层增透率模型可以较好地描述煤层增透率的空间分布规律,其与现场数据的相关系数和拟合优度均大于0.96。In order to study the coupling evolution law of stress-seepage field in high stress zone under the topcoal caving method,a permeability model under three-dimensional stress was established for coal.The model consists of two parts:the transverse isotropic model based on the matchstick model,and an elastic system composed of coal matrix and fractures.The permeability model is combined with the spatial distribution law of stope stress field to construct the spatial distribution model of the mining-induced coal permeability change ratio(MPCR).Laboratory test results under different conditions of confining,axial and gas pressure are compared with permeability models.The results show that:the permeability decreases exponentially ss the load and gas pressure increase.The permeability model can quantitatively describe the change of coal permeability under loading and unloading conditions,and the correlation coefficient and fit goodness obtained by comparing the results with multiple sets of experimental data are greater than 0.9.The MPCR spatial distribution decreases exponentially with the increase of distance from the working face,and can be divided into four stages:The stress stabilization phase of virgin rock,the MPCR decreases with increasing stress,the MPCR increases with decreasing stress,the constant MPCR with the damage of the coal.According to the comparison between permeability model and field data,the permeability of coal seams increases in stages of the MPCR increases with decreasing stress and the constant MPCR with the damage of the coal,covering the range of coal seam of 55.62 m(Lr=55.62 m).The model can better describe the spatial distribution of MPCR,and the correlation coefficient and goodness-of-fit coefficient with the field data are greater than 0.96.

关 键 词：横观各向同性 渗透率模型 增透率模型 增透范围 

分 类 号：TD325[矿业工程—矿井建设]