摘要
采动岩体变形与渗透特性是工作面突水防治研究的基本问题。采用理论分析和数值模拟计算方法,分析了岩石变形–渗透特征及其三维定量关系,研究了煤炭开采中回采工作面围岩应变场、渗透系数场分布及其控制因素。研究结果表明,采动岩体渗透性变化主要取决于应变状态及应变增量,且随着垂直于裂隙的张应变的增加而增加;工作面后方垮落带和煤壁边缘的剪碎带产生剧烈的采动拉伸变形,渗透系数较采前显著增大,而支承压力区和整体移动带岩层产生较大的采动压缩变形,渗透系数较采前明显减小;工作面围岩垂向渗透系数较水平渗透系数增加的幅度及增加区的范围小,但对水体下采煤工作面涌水起主导作用。加快工作面推进速度、减小工作面斜长和采高能降低采场围岩渗透系数增加幅度,并将渗透系数场变化范围局限在采区附近,能有效减小采动对原始煤岩层渗透性的影响。
The properties of mining-induced rock mass deformation and permeability are basic issues for water inrush prevention in working face.Based on tbe theoretical analysis and numerical simulation method,the deformation and permeability characteristics of the rock and its three-dimensional quantitative relationship are analyzed.The distribution of the stress field,the permeability field and the controlling factors of the surrounding rock in the coal mining face are studied.Results show that permeability coefficient of mining-induced fracture rock mass is closely related to its strain state and strain increment,and increases with the tensile strain perpendicular to the fractures.Strata in advanced abutment pressure area of working face and overall movement belt are compressed thus exhibit decreased permeability,while strata in caving zone and shallow layer forward the working face are in the state of stretching defonnation and possess increasing permeability,which shows a lai^er range of increasing area about permeability coefficient vertically compared to horizontally.Vertical permeability variation dominates water burst in face when coal mining is underneath water bodies.Accelerating advance speech decreasing dip length of working face and mining height can decrease the permeability coefficient increase degree of surrounding rock,and the variation range of permeability coefficient field is limited in neighboring mining area.Therefore,the influence on primaiy strata permeability induced by mining is minimized.
作者
师修昌
孟召平
SHI Xiuchang;MENG Zhaoping(School of Construction Management and Real Estate,Henan University of Economics and Law,Zhenzhou 450046,China;College of Geosciences and Surveying Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2018年第2期143-150,共8页
Coal Geology & Exploration
基金
国家自然科学基金项目(41372163)
国家科技重大专项课题(2016ZX05067-001)~~
关键词
工作面围岩
采动应变
渗透性
渗透系数场
surrounding rock in working face
mining-induced strain
permeability
permeability coefficient field
