Breakage Characteristics Of The Group A Coal Seam Floor And Evaluation Of Discharge On The Aquifer Of Limestone

In rencent years, with the exploitation of mining toward more and more deep coal seam, probability of water inrush risk also increases. It is a critical issue that studying the characteristics of the rock deformation and failure under the influence of mining and the variation of groundwater seepage field in lower limestone aquifer for evaluating the possibility from limestone water inrush correctly and providing the effective control measures.Taken Xinzhuangzi coal mine as a studied objective.after investigated the hydrogeological conditions and characteristics of limestone in Taiyuan formation, some parameters, which are from A1 coal seam to C33 limestone layer in 63 mining aera, including physic and mechanical, permeability, and the water-resisting property of strata, have been tested. Under the different mining conditions, the destroyed regulation of coal seam floor was simulated with FLAC3D software. The factors of affecting the depth of destroyed floor, were determined by orthogonal test, including workface width, coal seam depth and water pressure. The hydrogeological conceptual and mathematical model of strata from A1 coal seam to C33 limestone layer in 63 mining aera were established. The divided aera parameters of aquifer were obtained by Modflow software, and then the discharge of the aquifer was evaluated according to the identified model. At last, the risk of water inrush in 63 mining aera was forcasted using water-blocking factor theory and assessment method of water inrush coefficient, and the corresponding prevention and treatment measures were provided.