Research On The Exploration And Treatment Of K₂ Limestone Water Hazards In The Eastern Part Of The Chenghe Mining Area,Weibei Coalfield

At the present time,the elevation of the floor of the No.5 coal seam of the No.5 coal seam of the main mining area in the Chenghe mining area of Weibei coalfield is below the level of the static grey water mark of the Austrian ash,accounting for more than 90%of the area under pressure mining.In recent years,with the development of grouting from the shallow to the deep in the mining activities in the Chenghe Mining Area,the hydrogeological conditions in the eastern part of the mining area are quite different from those in the west.Except for the Ordovician limestone aquifer,the K2 limestone in the shallow part of the 5th coal seam floor.The aquifer is within the scope of mining damage and its water content is relatively strong.Once the hydraulic connection with the lower part of the ash occurs,it is extremely threatening to the coal seam exploitation.Under the condition that the hydrological exploration work is not carried out,the existing traditional grouting reinforcement in the single mining area is used to reinforce the floor slab.The method of aquifuge is not applicable,and the comprehensive control strategy for K2 limestone and aeolian karst aquifer is not clear..In this paper,we carried out a large number of research and exploration work in Shanyang and Anyang mines in the northern Qinghe coal mining area with the above-mentioned characteristics of hydrogeological conditions.We studied the water content of the K2 limestone aquifer and the lower austenitic karst aquifer of the Taiyuan Formation in the shallow part of the coal seam floor.Specially,through pre-drilling,geochemical exploration and other means,combined with underground drainage and water tests,etc.,an analysis was carried out,and a corresponding water disaster treatment project was arranged at the mining working face of Anyang Minefield.Finally,a single conventional grouting reinforcement technology was determined and utilized.It is not suitable for the treatment of coal seam water hazards in the above-mentioned areas.Based on the exploration of the hydraulic connection between the K2 limestone and the aerolite aquifer,a corresponding advanced drainage and pressure relief should be adopted for different blocks,combined with the regional sealing depth.The way of water-conducting aisles is treated as follows.It is believed that the K2 limestone aquifer of the local coal bed in the eastern part of the Chenghe mining area has strong water-richness.The distance between the aquifer and the 5 coal is mostly within the damage depth of the coal mining floor,and it is not meaningful to adopt advanced grouting.Large,in which the hydraulic connection between the K2 limestone aquifer and the lower ash limestone aquifer is identified as the treatment of water hazards.key.Based on the research results obtained so far,combined with the future production layout of the mine,the work that needs to be continued in the later period is also elaborated.