Evaluation Of Water Hazard In-950 Level Coal Seam Floor Of Donghuantuo Mine

The water pressure in the bottom slab of Kailuan Donghuantuo Mine increases further after mining from the shallow part to the deep part of-950 level,and the threat of water damage in the bottom slab is more serious.Based on the principle of superposition of multi-source information,it is important to apply the“vulnerability index method”to evaluate the risk of water breakout in the bottom slab for deep coal mining.On the basis of collecting data from the drill hole logs in the study area,the numerical and spatial distribution characteristics of the thickness,dip angle and depth of burial of the12_-1 coal seam at the-950 level were studied by combining statistical and geological graphical analysis.Based on the collection of fault structure logs,the intensity of fault development was characterized by fault line coverage and influence buffer zone,fault endpoint and fault scale index.carried out a comparative analysis of the lithology of the stratum at the bottom of the 12_-1 coal seam based on the borehole bar graph,and classified26 water-isolated rock layers.The analysis determined the factors and index system of the influence of the bottom slab sudden water,and Based on the principle of AHP-GIS graphical overlay,the“vulnerability index”zoning map of water hazard of the bottom slab was drawn and the water hazard zoning evaluation was carried out.The conclusion shows that:the 12_-1 coal seam at the-950 level of Donghuantuo Mine belongs to the slowly inclined more stable-unstable coal seam,which is thicker in the northern part of the study area and has a large influence on the bottom damage zone after mining.The fault in the study area is mainly distributed in the south 2-3 mining area,the area covered by the fault line is 14880.77m²and the area affected by the fault is 31,706.98m²;the area of the fault endpoint crushing zone is 12566.37m² and the area of the fault endpoint affected zone is 98853.37m²;The important water-bearing layers that are threatening to the coal seam floor are 3 aquifer and 10 aquifer.The main control indexes of the coal seam base plate water breakout include coal seam thickness,coal seam depth,fault cover and influence buffer zone,fault scale index,fault endpoint distribution,3 aquifer thickness,10 aquifer thickness,3 aquifer to 12_-1 coal seam base plate water barrier thickness,10 aquifer to 12_-1coal seam base plate water barrier thickness.Based on the“vulnerability index”,the study area is divided into safe,safer,more dangerous,dangerous and extremely dangerous zones for water damage in the basement.The extremely dangerous zone is located near the fault fragmentation zone and near hole 70 where the thickness of the water barrier is thin,the thickness of the coal seam is thick and the burial depth is deep,with an area of about316708.1m²;the dangerous zone is located in the fault impact buffer zone.The dangerous area is distributed around the buffer zone of fault influence and the holes of 73 and 70 with large water seam thickness,strong water richness,large coal seam depth and large water pressure,the area is 788636.3m²;the more dangerous area is mainly distributed between exploration line 16～19,the area is about 1505945m²;the safer area is distributed north of exploration line 16 and between exploration lines 19～21,with an area of about The safer zone is distributed to the north of the 16 exploration line and between the 19～21,with an area is 3306639.18m²;the safe zone is distributed around holes of 52,60,5,51,68,46 and107,and the area is about 1722571.6m².Figure 40;Table 23;Reference 65...