| The Cenozoic bottom aquifer of Xinhu coal mine(hereinafter referred to as bottom aquifer' i.e.'4th aquifer')directly covers the coal measure strata.The '4th aquifer' in the mine field are unevenly distributed,and many places show the characteristics of '4th aquifer' high water level,which poses a great threat to the mining of shallow coal seams.Therefore,it is of great significance to study the hydrogeological characteristics of the '4th aquifer' systematically and comprehensively.On the basis of consulting domestic and foreign literatures and collecting mine geological and hydrogeological data,this paper focuses on sedimentary facies analysis of third aquiclude(hereinafter referred to as '3th aquiclude')and '4th aquifer' in Xin Hu coal mine(minefield).Using facies section comparative analysis and plane facies analysis to determine its sedimentary characteristics.Secondly,the groundwater level characteristics and Groundwater Hydrochemical Characteristics of each aquifer are systematically analyzed to explore the hydraulic relationship between the '4th aquifer'and each aquifer.On this basis,combined with the theory of groundwater system,To make sure the causes and scope of '4th aquifer' high water level.And to complete The water rich zoning of'4th aquifer',which provides a hydrogeological basis for the prevention and control of '4th aquifer'.The main conclusions and understandings are as follows:1.The sedimentary facies analysis shows that:Affected by the ancient bedrock surface,the '4th aquifers' are mainly distributed in the low-lying areas on the north and south sides of the mine field,with a thickness of 0-22.26m.It is a set of sedimentary system dominated by eluvial and Deluvial facies.The'3th aquiclude' are widely distributed in the area,with a thickness of 108.4?263.6m.It is a stable aquiclude composed of lake-delta-meandering river sedimentary system2.K++Na+accounts for more than 80%in the'4th aquifer' water,Cl-and SO42account for a large proportion of anions,which is Cl·SO4-Na water.The '4th aquifer' in the area are mainly north-south runoff,with high water level and less affected by the water level changes of other aquifers.In general,the '4th aquifer' water is in a stagnant state,and there is a certain hydraulic connection with the lower red bed,3 coal,8 coal and Taiyuan ash aquifer.3.According to the hydraulic connection between aquifers,the groundwater in Woyang mining area of Xinhu coal mine is divided into local,intermediate and regional groundwater flow systems by using the groundwater system theory.The '4th aquifer' belong to the regional groundwater flow system,Combined with the analysis of structural characteristics,determine the genesis of "four containing" high water level,and then delineates the high water level area.Finally,it is determined that the potential source area of'4th aquifer' is the limestone outcrop zone in Longshan Town with high altitude in the northeast of the mine field.4.The permeability coefficient of '4th aquifer',aquifer thickness,sand gravel layer thickness and sand gravel layer number are selected as the main control factors of water yield.Use the analytic hierarchy process to calculate the weight coefficient of each factor.After the normalized superposition of various topics with the help of GIS software,the'4th aquifer' are divided into weak water rich area and very weak water rich area.The results are verified by the unit of water surge data,which can provide suggestions and guidance for subsequent coal mining.Figure [56] Table [15] Reference [87]... |
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