| During the developing process of coal resources in west China,this paper is focusing on the special hydro-geological problems in Turpan-Harmi coal base,which is one of the four largest coal bases built in the Xinjiang Province.Moreover,this paper studied the key problems which threaten the mining operation and cause water disaster in Turpan-Harmi coal fields.The Dananhu mining area is selected as the study area,which is located in the Jurassic coal-rich areas of Turpan-Harmi mining area.Then,the basic theoretical researches have been conducted in the coal-rich formations of the study area,and we studied the water control mechanism,medium characteristics,hydrodynamic characteristics and water prevention technics.The results have been applied in the water proof treatment of the first mining area of No.5 well in Dananhu mining area.The main conclusions in this paper are:(1)Depend on the field investigation,water quality and isotope analysis,we systematically analyzed the hydro-geological conditions and sedimentary evolution process in the Harmi coal field.This paper identified the forming and evolution process of ancient lake bed.The water resources in the study area are mainly recharged by snowmelt from Tianshan Mountains,and ridgy gaps in the Shaer Lake are served as the channel for groundwater recharge.For the arid and semi-arid desert regions,the control effects of ancient lake bed on the hydro-geological conditions have been studied.(2)Based on the scanning electron microscopy(SEM)and pressure mercury test,the characteristics of pore structure in Jurassic sandstone aquifer.Testing results show that the average porosity in III-1 aquifer and sandstone can reach up to 19.9% and 18.2%,respectively,which is much higher than the porosity(1.1-2%)of sandstone in eastern Carboniferous and Permian system.Therefore,the medium in the study area has characteristics of high porosity and double-medium,which can provide a preferable medium condition for preservation and movement of underground water.(3)By conducting the pumping test in multiple wells and parameter estimation,and combined with the medium characteristics of Jurassic aquifer,the permeability coefficient K(4.33m/d)and specific yield(1.18 l/s m)of III-1 aquifer have been calculated via the Boulton model.The aquifer has hysteretic and double medium characteristics.Combined with the hydro-chemical analysis,the aquifer is mainly consisted by static reserve,and has characteristics of high permeability and high contents of total dissolved solids.(4)Based on the medium condition,structure features,water control mechanism and flow field evolution of ancient lake bed in the study area,this paper proposed a key technic(controlling mining in roof and drainage in floor)for preventing water disaster in No.18 coal,and successfully applied in the first mining area. |
PDF Full Text Request