Study On The Technology Of Coal Mining With Water Conservation Under The Accumulated Water In Goaf

In order to solve the contradiction between the shortage of water resources in China and the abundant water accumulation in the mined-out area of coal mines,based on the engineering geological and hydrogeological conditions of the Lingzhida coal mine in Shanxi,the upper coal seam(No.3 coal seam)has been excavated and the lower coal seam(No.15 coal seam)is being mined.A combination of on-site investigation,theoretical analysis and numerical calculation was used the technology of coal mining under water retention was studied.The research results can provide a reference for the coal mining with similar geological conditions in China.The main research results are as follows:(1)The numerical calculation model of mining overburden law is established.Firstly,the evolution law of mining stress field,displacement field and plastic failure area of upper coal seam(No.3 coal seam)is simulated,and then the evolution law of mining stress field,displacement field and plastic failure area of lower coal seam(No.15 coal seam)is simulated,the influence degree of mining lower coal seam(No.15 coal seam)on the development height of overlying water conducting fracture zone of upper coal seam(No.3 coal seam)is obtained.(2)The calculation formula of the depth of floor failure is fitted;the development height of the water conducting fracture zone of the 15101 working face is measured on site,and the numerical simulation results,the similar geological conditions of the mining area and the field measurement results are used as the data source to fit the calculation formula of the development height of the water conducting fracture zone of the roof.(3)The thickness of the protective layer is determined according to the actual situation of the mine.In this paper,the criterion of determining the influence degree of mining lower coal seam(No.15 coal seam)on goaf water accumulation is given.The influence degree of mining lower coal seam(No.15 coal seam)on goaf water accumulation in lingzhida coal mine is divided into safety area,micro influence area,threat area and danger area.(4)This paper puts forward the technical scheme of water storage in leaping layer and transfer in the same layer in the goaf.Taking the goaf as the underground water storage space in lingzhida mining area,the water storage capacity of each underground reservoir is calculated,which provides reference for the practice of water conservation and coal mining engineering in lingzhida coal mine.There are 46 figures,17 tables and 102 references in this paper.