| The Jinjie mine belongs to Jurassic system coalfield,which located in the north end of the Loess Plateau in Northern Shaanxi and the southeast of Maowusu desert.There Quaternary Salawusu formation phreatic aquifer and Middle Jurassic Zhiluo formation confined aquifer of weathered rocks are overlying the main mining seam named 3-1 in Jinjie mine,and have strong water yield property by them.In addition,a thin clay aquifuge exists between two aquifers.As the height of water flowing fractured zone due to mining is more than normal overlying bedrock thickness at the thin bedrock section,the weathered bedrock confined aquifer becomes the main water bearing strata of coal mine.In the past,people used dewatering by arranging drain holes uniformly in working face for the threat of mine water disaster of coal roof aquifer,so the water discharge during mining can be reduced.Nonetheless,the excessive dewatering happened frequently,such as too many drilling holes,a long time and a large amount of dewatering,as a result of the inadequate understanding of the dewatering technology that restricts mine economic development.Hence,it is necessary to make a study on optimization of dewatering technology for mining security and cost reducing,so as to have important instructive meaning to safety,efficient and economic mining.The main contents in the thesis are summarized as follows:Firstly,based on the geology and hydrogeology data from Jinjie mine,the paper makes analysis on the tendency and composition of mine discharge,as well as the influence factors of it,and the quantity of dewatering is the main influence factor of mine discharge is put forward.Secondly,the problem has been brought forward by analyzing dewatering of working face,for instance,it is too many drilling holes,a long time and a large amount of water.For solving the problem,dewatering test of 31204 working face was conducted.As a result,the quantitative index and distinguish criterion of dewatering is presented,on account of analyzing the quantity of water of hole group and single hole,residual hydraulic head,stability time of dewatering,influence radius and segmentation distance of dewatering.Thirdly,as the three-dimensional numerical model of unsteady flow of groundwater established and the hydrogeology parameters obtained,and then distinguished,which provide the groundwater flow numerical model for the optimal management model of dewatering to simulate and predict.Lastly,while using the response matrix method to coupling three-dimensional transient flow numerical model with optimal management model,and distinguish criterion of dewatering effect as a restrictive condition,the optimal management model of water drainage of 31205 working face built,then.Besides,six different schemes of water drainage set by segmentation distance,quantity of drilling holes and time,and using the Lingo language associated with 0-1 integer programming algorithm for model solution,a contrastive analysis of different schemes according to the results is given.On the basis of the analysis above,the optimal scheme of dewtering is proposed. |
