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

The destruction condition of coal-floor was determined by mathematical equation combined with the topo- graphical 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,expan- sion 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 nu- merical 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 wa- ter-inrush accidents in mine.