Analysis On The Influence Of Mining Activity On Groundwater In A Coal Mine

The main research task of this paper is to predict the height and extent of the formation of the hydraulic fracture zone in the mining activity,predict the influence of pumping and drainage in different stages on loose groundwater,and finally analyze the possible geological environment problems.The research result is to demarcate the scope of influence of the water-passing fractures and groundwater level drop,and propose reasonable suggestions for the problems to minimize the impact of mining activities on the geological environment.The loose layer in the study area is mainly composed of clay,silt,and sand pebble layers.According to the water-bearing characteristics of the formation,it is divided into two upper and lower aquifers.The upper aquifer is submersible and the lower aquifer is confined water.The loose layer has good water-richness and is the main aquifer in the area.The local production and domestic water mainly come from the aquifer.From top to bottom,the mining coal seams in mining areas are respectively1#?2#?3#?4_-1#?4_-2#?4_-3#.Among them,the height of the conductivity fracture zone formed in the 1#coal seam is the largest,and the average height of 62m,4_-3#coal seam is the largest in the water conductivity fracture zone.The area is 3.42 km²,accounting for 21%of the area of mining area,and the area of water conduction crack caused by all mining coal seam is 4.55km²,accounting for 28%of the area of mining area.Application of Visual MODFLOW Software to Predict the Effect of Pumping Drainage on Loose Bed Groundwater in Different Stages of Mining Area.The establishment of the groundwater numerical model,combined with the different mining stages.During infrastructure construction,the upper aquifer drainage volume1783m³/d,core descent 84m,influence range of 1382m;the lower aquifer drainage volume 4710m³/d,core descent 148m,the influence range of 1455m;during the production,The leakage of the lower aquifer is 4282m³/d,core descent 88m,the influence range of 2329m.During the production period,the drainage and drainage of the mine have little effect on the groundwater flow field in the upper aquifer.The groundwater flow field in the lower aquifer has a great influence,and there is an obvious drop funnel in some places.In general,the trend of groundwater movement in the loose layer remains unchanged.Groundwater is still in equilibrium.Geological environmental issues arising from mining activities,some suggestions are put forward from the aspects of safety production,reducing the influence of groundwater,comprehensive utilization of groundwater,improving the utilization ratio of resources,verifying data and so on.Reasonable mining planning and technical means should be taken to avoid the influence of fracture zone,so as to reduce the leakage of groundwater.Selecting advanced mining technology to reduce the dislocation and influence of mining on the upper strata of coal seam,and to reduce the height of fracture zone,so as to reduce the influence on the upper aquifer.The height of fracture zone is measured in real time,the calculation formula of fracture zone height suitable for mine area is deduced,and Redefine the height and scope of the fracture zone to ensure safe production and resource utilization.The water discharge of mine pit and the water level of the lower aquifer are observed,the chemical analysis model of water is established,the source of leakage is judged,and the model is verified.Monitoring of water levels in villages within the affected area to ensure water supply.