Study On Hydrogeological Characteristics And Water Disaster Prevention Technology Of Yili No.1 Mine

Yili No.1 Mine is located in Yili Prefecture,Xinjiang.The surface is covered by the Tianshan Mountain front alluvium or diluvium and is directly recharged by Tianshan Snow Melt Water.It has an unconformable contact with the underlying coalbearing strata,and the groundwater recharge and runoff conditions are complicated.In this paper,based on the analysis of the preliminary exploration data and the hydrogeological reconnaissance engineering data,the hydrogeological characteristics of the main aquifers in the study area are analyzed for the special water damage problems such as water inrush from the top and bottom of the mine during the test mining stage.The in-depth study on the failure law of the weakly cemented roof of the Jurassic was carried out,revealing the formation mechanism of water damage in the study area,and the corresponding prevention and control techniques were proposed.The main results are as follows:(1)Based on the structural characteristics of the alluvial deposits in the study area and the analysis of the characteristics of snow-melt hydrology,combined with the data of the reconstruction project,the hydrogeological characteristics of the piedmont alluvial deposits in this area were revealed.The concept of “slope transit flow” was put forward,and it was considered that it has little effect on mine water filling;(2)Through the rock sample test,combined with the reconstruction drilling data and the water release test,the media characteristics and water-rich laws of the Jurassic sandstone aquifer were studied.The results showed that the Jurassic sandstone aquifer in the study area had the characteristics of high clay mineral content,small pore diameter(less than 2μm)and low permeability,the main aquifer roof sandstone two sandstone aquifers were weak in water and the bottom aquifer is medium-rich in water.,permeability coefficient K = 0.65m/d;(3)Evaluating the risk of water inrush from the Jurassic aquifer and the feasibility of its dredging: the water inrush coefficient of some sections of the test face was supercritical,which had the threat of water inrush from the floor,but the recharge conditions of the bottom aquifer were poor,and the dredging property was good,and a targeted dredging scheme was proposed;(4)The damage law of the weakly cemented roof of the Jurassic and the development height of the “two zones” were measured.The measured results were as follows: the ratio of the height of caving zone to the thickness of the mined is 4.3,and the ratio of the height of cracking zone to the thickness of the mined is 11.8-11.9,and compared with the measured results of mines with similar conditions;(5)Explained the mechanism of water inrush from the roof,based on the measured results,selected the typical working face to carry out the evaluation of the risk of mud,and put forward the technical methods of prevention and control.