Study On "Five Maps,Three Zones And Two Zoning Plans" Water Conservation Mining Method In Yushen Mining Area

In order to solve the contradiction between the fragile ecological environment and high-intensity coal mining in the northwestern region of China,based on the engineering geological conditions and hydrogeological conditions of Yushen mining area in northern Shaanxi,I used theoretical analysis,theoretical calculation,numerical calculation and field observation to study the “five maps-three zones-two-zoning plans” water conservation coal mining method of Yushen mining area.The research results can provide theoretical and practical reference for water conservation coal mining in the northwest mining area of China.The main research results are as follows:(1)The analytic hierarchy process is used to identify the influencing factors of water-conserving coal mining,and a four-level structural model for the influencing factors of water-conserving mining is constructed.The model includes three primary factors,nine secondary factors,sixteen third-tier factors and twelve fourth-tier factors,and the weight of each influencing factor are obtained.(2)Based on the weight distribution results of the factors affecting coal mining,and considering the needs of mine production,the contour map of overburden thickness,the combination relationship map of strata,the map of water-rich partition of aquifer,the aquiclude thickness contour map and the contour map of the coal seam were drawn..(3)The characteristics of the caved zone,the water-conducting fracture zone and the protective zone were studied.According to the field measured data,the formula for calculating the height of the caved zone was fitted.Based on the field measurement,numerical calculation and theoretical analysis method,the calculation formula of the height of water-conducting fracture zone of five different strata,including sand-based,sand-based,bedrock,soil-based and burnt-rock,were obtained.Based on the water-blocking evaluation coefficient,the calculation formula of the height(thickness)of the protection zone was obtained by converting the water-blocking evaluation coefficient between the bedrock and the clay.(4)Based on zoning criteria for the impact degree of mining on groundwater.According to the calculation formula of the above “three zones” height combined with the thickness of bedrock and the thickness of the clay in the geological exploration data.I classified the mining impact degree of coal mining on groundwater into five categories,including severe impact,severe impact,medium impact,weak impact and no impact in the Yanshen mining area.The degree of groundwater impact of the coal mining was divided.(5)Systematic analysis of applicable conditions of water conservation coal mining technology such as high-limited water conservation coal mining technology,filling water conservation coal mining technology,partial filling water conservation coal mining technology and narrow strip water conservation coal mining technology in Yushen mining area.The applicability of the above-mentioned water conservation coal mining method is divided.Under the guidance of the results of “two zoning plans” water conservation coal mining method,Yushuwan coal mine,Fuyang coal mine and Yubujie coal mine successfully implemented the practice of water conservation coal mining.