Numerical Simulation of Main Controlling Factors of Water Inrush from Concealed Collapse Column of Floor

In order to understand the role of mining process in the failure and water inrush of the surrounding rock of floor collapse column, the basic characteristics of underground karst collapse columns in Geting Coal Mine were concluded by theoretical analysis, numerical simulation and physical detection. Take SX1 collapse column discovered at working face 2160 of Geting Coal Mine as the research object. FLAC^3D was used to simulate the variation of the stress field, seepage field, displacement field and plastic failure area of coal seam roof and surrounding rock of collapse column during mining. The results show that the stress field, plastic failure zone, displacement field and seepage field around collapse column increase with the increase of working face mining height and aquifer pressure. Collapse column belongs to natural low-stress concentration area. With the increase of advancing distance, the original stress field is redistributed, and the displacement of surrounding rock at the top of collapse column increases continuously.