软岩底板突水机理分析及数值试验

Numerical test and mechanism analysis of water-inrush on soft rock floor

结合煤矿地形特征和煤层赋存条件,通过数理方程确定底板发生破坏的条件,实现对突水通道的初步预测与定位;利用RFPA软件对煤矿软岩底板进行突水机理数值试验研究,进行煤层底板突水路径的应力场、渗流场和声发射演化过程分析,再现底板突水的形成过程,即底板在水压驱动下出现裂纹萌生、扩展以及水压跟踪传递,最后底板隔水层变成导水通道层。研究结果表明:董家河煤矿可通过调控煤层底板突水的条件使之不发生突水事故;该数值计算方法适用于具有类似地质条件的煤矿,可为煤层底板突水机理研究和防范矿井突水事故的发生奠定理论基础和方法指导。

The destruction condition of coal-floor was determined by mathematical equation combined with the topographical features and occurrence condition of coal seam,and the preliminary forecast and localization of water-inrush channel was realized.The numerical tests on the water-inrush mechanism of soft rock floor in coal mine were carried out by using RFPA software.The stress field,seepage field and evolution process of acoustic emission of water-inrush path were analyzed.Meanwhile,the water-inrush formation process was reproduced,that is,the crack initiation,expansion and water pressure tracking transmission emerged in succession under the water pressure drive on coal-floor,and finally the impermeable layer changed into water guiding channel layer.The research results show that the water-inrush accidents can be avoided through controlling the conditions of coal-floor water-inrush in Dongjiahe Coal Mine.The numerical calculation method is applicable to coal mines that have the similar geological conditions.The study provides a theoretical basis and method guidance for the study on the water-inrush mechanism of coal-floor and prevention of water-inrush accidents in mine.