Study On Hydrological And Engineering Geological Characteristics Of Fault Sun And Mining Effect In Longdong Coal Mine

This paper takes the fault Sun in the East No.2 mining area of Longdong coal mine as the research object.On the basis of collecting geological data of mines,drilling techniques were used to investigate the position and the water content and water permeability of fault Sun.Rock uniaxial compression test,splitting test,and immesion test were carried out based on the fractured strata and rock cores on both sides of the exploration project and rock physical and mechanical parameters of the fault zone and rock masses on both sides were obtained,and the engineering geological characteristics of the fault Sun were evaluated.Based on the geological conditions,An engineering geological model of the study area was established.Similar materials simulations and numerical simulation methods were used to simulate the mining effects of the rock masses in the near fault zone and the roof and floor of the coal seam.Based on fault mining effects and formula calculations,a reasonable determination of the width of waterproof pillars of fault Sun was made,which provided a scientific basis for the layout of working face and prevention of water hazards in the East No.2 mining area.The main achievements are:1.Through analysis of the existing exploration data,combined with the underground exploration data,the position and basic characteristics of the fault Sun are further determined.2.Based on the pumping test and downhole exploration data,it is concluded that the fault Sun is a fault with weak water content and poor water conductivity.In addition,the fault zone rock is broken,the integrity is poor,and the overall strength is low.The rock in the fault zone is prone to plastic deformation after encountering water.3.A similar material model containing faults Sun was established and the coal seam mining process simulation test was conducted,the features of fault mining effect under the condition that the coal pillars were continuously reduced with the advancement of the work surface were analyzed,and the mining coal mining has an advanced impact range of 30~50m.4.Using FLAC3D software to establish a numerical model,the numerical simulation of coal seam mining under different coal pillar widths was carried out and the characteristics of fault mining effect under different coal pillar widths were studied,and the mining coal mining has an advanced impact range of 30-40m.5.Taking into account the characteristics of the change in the drop of fault Sun,the profile of the exploration line is used as the calculation object.The width of the waterproof coal pillars at different positions on the fault Sun is calculated using the specification formula,combined with the characteristics of fault mining effects.The width of the fault waterproof pillar was determined accordingly.