Study On Evolution Characteristics Of Water-blocking Performance Of Collapse Zone Of Subsided Column Under Mining Influence

The water inrush from the collapse column of mine is one of the important disasters that endanger the safe production of mines.The casualties and economic losses caused by the water inrush from the collapse column are even greater.The research on the mechanism and development characteristics of the water inrush of the collapse column is carried out for the safe production and coal mining work of the mine.It is of great significance to optimize the design and increase the coal output.The thesis focuses on rock mechanics theory research,hydrogeological condition analysis,on-site geophysical exploration and numerical simulation.It mainly analyzes and predicts the water enrichment of the collapse zone of the collapse column,and the influence of mining on the mining of the spring by FLAC3D numerical simulation software.The mining degree of No.3 coal seam in coal mine 303 mining area was analyzed by multi-angle analysis.The stress distribution of the collapse column and its surrounding rock,the stress distribution formula of the collapse column under the conditions of self-weight,surrounding rock stress and underground confined water are analyzed.The criterion of the activated water guiding of the collapse column is derived.The collapse column is calculated.The width of the surrounding rock infiltration zone and the plastic failure zone,and the depth of the floor of the roadway.And the preconditions for the occurrence of water inrush accidents are obtained,so as to predict and prevent the water inrush from the collapse column.The geology and hydrogeological data of the minefields in the Shiquan coal mine and surrounding areas were collected and the hydrogeological data of the mines were classified.The geophysical methods of ground transient electromagnetics were used to infer the karst development anomaly in the 200m range of the Ordovician limestone top interface.The water-rich condition of the structure(collapse column)in the mining area of the coal mine 303 was predicted and analyzed.Based on the actual situation of the 303 mining area,a three-dimensional fluid-solid coupling mathematical model was established.The FLAC3D numerical simulation software was used to obtain the seepage field and displacement field of the surrounding rock and roof of the roadway when the coal seam was excavated under the pressure of 6Mpa,The damage of stress field and plastic zone is changed.Finally,the main water hazard threats of No.3 coal seam mining in the mine field are proposed,and the prevention and control measures of Collapse column water damage are put forward based on the actual situation.