Prediction Of The Risk Of Water Inrush In The Middle And Westernpart Of Hongliulin Mine

Water inrush from ground cracks is one of typical mine water inrush disaster in shallow buried coal seams when the first mining face passes through gullys.The surface of the shallowburied coal seams in the Jurassic coalfield in northern Shaanxi is mostly loess gully landform,and the flood accident caused by the continuous flow of water in the gully or the flood in the rainy season breaking into the underground along the mining through cracks seriously threatens the safety of mine production.This paper takes the Hongliulin mine as the research object,and carries out the research on the risk prediction of the water inrush of the surface mining cracks in the ditch mining,which has important theoretical and practical significance for the safety production of shallow buried coal seams.The static development law and dynamic development law of surface mining fractures in the 5-2 coal seam 25211 working face and the 4-2 coal seam 44204 working face in the study area were carried out by means of unmanned aerial vehicle low-altitude remote sensing survey and "single fracture multi-point marking" field measurement.The research results show that the plane distribution types of surface mining fractures in this area are mainly divided into two categories:parallel-cut fractures and parallel-groove fractures.With the advancement of the working face,the width and height of the parallel cut-hole fractures in the working face first increase and then decrease.The width and offset of the mining fracture near the cut-hole are much larger than those of the parallel cut-hole fractures in the working face.Through the analysis of the relationship between the development position of new fractures and the mining position of the working face,the spatial position of the new fractures in the mining of the 25211 working face is ahead of the mining position of the working face,and the spatial position of the new fractures in the mining of the 44204 working face generally lags behind the mining of the working face.The reason is related to the soil-base ratio of the working face and the mining thickness of the coal seam.The relationship between the development heights of the upper,middle and lower sections of the caving zone and the water-conducting fracture zone and the burial depth of the coal seam is used as the key index to determine the safety zone of caving.Dangerous area,high-risk area,medium-risk area,general-hazardous area,and safety area are classified into five categories,and a prediction map of the cracking safety zone of Lucaogou in the study area is drawn.The types of water intrusion under surface runoff are divided into five types:sand inrush type,strong water inrush type,moderate water inrush type,weak water inrush type and seepage type.On this basis,the zoning prediction of the type of water inrush and flood damage was carried out for Lucaogou in the study area.According to the development law of surface mining fractures in the mined working face,the geological conditions of the mined working face and the working face to be mined are compared.Developmental characteristics were predicted.Combined with the field-measured surface constant water flow in Lucaogou,the surface constant water flow in the first coal seam section is estimated.Based on the hydrological analysis module in the ArcGIS software platform,the watershed analysis was carried out on the intersection of the first mining face and the channel of each coal seam in Lucaogou in the study area as the watershed outlet.Using the indoor experimental platform of channel water inrush amount independently developed by the research group,a mathematical model for predicting the water inrush amount of mining fractures with different widths of the channel is obtained,and the channel water inrush amount after mining is predicted for each working face to be mined in the study area.Based on the prediction results of channel water inrush,the mine drainage capacity is used as the direct evaluation index to divide the mine water inrush into four levels:small,medium,large and extremely large.By superimposing the classification results of water inrush amount and the classification results of mine water intrusion and water damage types,the classification standard of channel water inrush risk is formulated,and the channel water inrush risk is classified as safe,low risk,medium risk,high risk and dangerous There are five types of extremely high,and the water inrush risk of Lucaogou in the study area in non-flood season and flood season is predicted by division.The results showed that the non-flood season was dominated by low and medium risks,and the flood season was dominated by high risks.