Similar Test And Numerical Simulation Of Coal Seam Mining In Tarangaole Mining Area

Coal energy has always occupied a very important position in China's energy system.The central and western regions have become the main coal-producing areas in China,and the Ordos Basin is the main coal-producing areas in the central and Western regions.With the continuous exploitation of underground coal resources,underground goaf gradually formed,and a series of problems such as surface subsidence caused by goaf also affect the quality of production and life of the people.The research on the law of rock mass movement,stress change and surface subsidence in overlying strata after coal seam mining will help us to mine coal resources more reasonably,reduce the surface subsidence caused by coal seam mining and other issues,which is of great significance for realizing the safety of coal mine and green mining and guaranteeing the safety of people's production and life.In this paper,the Tarangaole mining area in the west of Dongsheng coalfield,Ordos,is selected as the research area.By means of field investigation,physical and mechanical experiments,theoretical analysis,similarity simulation and numerical simulation,and by means of engineering geology and hydrogeology,the stress changes,rock mass migration law and surface of overlying strata caused by mining of3-1,4-1 coal seam in Tarangaole mining area are studied comprehensively.The characteristics of subsidence are analyzed.The influence of 3-1 coal seam mining on copper mining in overlying strata is analyzed.The ground subsidence value caused by coal seam mining is calculated and the development height of upper damaged rock mass is calculated.The results of traditional theoretical calculation,similar simulation calculation and numerical simulation calculation are compared comprehensively to verify the accuracy of the results.The main achievements are as follows:(1)According to the exploration data of different mines in Tarangaole mining area,the height of fracture zone and caving zone in overlying strata after miningiscalculated by using the theory of "three zones".It is concluded that when mining 3-1and 4-1 seams simultaneously,the total height of caving zone and fissure zone can reach 138.67 m,while the average distance between the roof of coal seam and the floor of copper mine is 130 m,so when mining 3-1 and 4-1 seams simultaneously,the average distance between the roof of coal seam and the floor of copper mine is 130 m.Coal seam mining at the same time will have an impact on the development of copper mine.(2)With the increase of mining area,the copper deposit produces larger shear stress,the range of plastic zone(reaching mechanical strength)increases year by year,and the copper deposit produces plastic zone(failure)after the second year,which may lead to fracture and fracture.(3)Excavation of 3-1 coal seam,in the fifth year,the maximum displacement of the floor of copper mine is 87.6 cm and the maximum displacement of the surface is83.3 cm;in the fifth year,the maximum displacement of the floor of copper mine is62.4 cm and the maximum displacement of the surface is 54.5 cm;in the case of simultaneous excavation of 3-1 coal seam and 4-1 coal seam,the maximum displacement of the floor of copper mine is 132.6 cm,and in the fifth year,the maximum displacement of the surface is 130.1 cm.It can be seen that the displacement caused by multi-layer excavation is not a simple superposition of single-layer excavation.(4)The excavation of coal seams 3-1 and 4-1 in Tarangaole mining area will inevitably affect the copper deposit above it,but the scope and thickness of influence will vary with the size of the mining area.Considering that precipitation is necessary for coal mining,which will destroy the occurrence environment of the copper mine,and once the plastic zone formed by mining develops to the copper mine floor,it will also destroy the water-resisting floor of the copper and change its hydrogeological environment and occurrence environment,so it is suggested that the work plan andemergency plan should be well prepared before mining the coal mine,and safety assessment should be established to avoid damage to the copper mine floor.