Feasibility Study On F15 Fault Reduction Of Coal Pillar In Working Face W3₂11 Of Qianyingzi Coal Mine

According to the relevant rules and regulations such as the"Coal Mine Water Control Rules"and other relevant regulations,in the process of coal mining,when a fault with a large fall is encountered,it is necessary to leave a fault protection pillar to ensure safe mining.If the width is too wide,it will cause Loss of coal resources;if the reserved width is too small,it will cause safety production accidents.Therefore,it is very necessary to carry out technical research on the reasonable retention of fault coal pillars.The thesis takes the W3₂11 working face of the lower wall of F15 fault in Qianyingzi Coal Mine as the research object,on the basis of consulting the domestic and foreign frontier technology of fault coal pillars,combined with roadway crossing,underground long borehole exploration,surrounding borehole exposure and 3D earthquake And other data,systematically analyzed the F15 fault drop,water-bearing characteristics and swing patterns.Rock samples were taken for analysis and testing of rock mechanics and hydraulic properties,an engineering geological analysis model was constructed,and FLAC^3Dwas used to analyze the stress-strain evolution law of coal pillars with faults of different scales under the influence of mining.The conclusions obtained are as follows:?1?F15 fault drop is a normal fault,with an extended length of 3.83km and a drop of 0-60m.It is located near the west wing wind lane of W3₂11 working face.The original 60m fault waterproof coal pillar was left,and more than 300,000 tons of coal was pressed;3D seismic and downhole drilling results show that the fault drop has the characteristics of large in the middle and small in both ends;transient electromagnetic detection results show that the value of the apparent resistivity contour of the fault fracture zone is higher overall and the difference is small.The No.1 joint road construction fault detection has a long borehole main hole and one branch hole with a total engineering volume of 743m.No borehole has produced water,indicating that the F15 fault is a non-water-bearing fault;?2?Based on the rock mechanics test results,the W3₂11 work is determined The coal cover rock type of Face 3 is medium hard cover rock,which has good barrier and water blocking capacity;according to the relevant specifications,the height of the water conduction fracture zone after the mining of the working face is predicted,and FLAC³DD simulation software is used to simulate the retention of different coal pillars The distribution law of the plastic zone and displacement zone caused by the width;?3?Using different theoretical calculation methods to calculate the width of the safety protection coal pillar of the F15 fault,combined with numerical simulation software to analyze the results It is determined that the F15 fault can be mined without pillars.Considering that the rock near the fault zone is broken,its own bearing capacity is poor,and the roof management is difficult.To ensure safer and more reliable driving and mining,the W3₂11 working face is close to the F15 fault.3-Mining of 5m small coal pillars.