Lane Layers Arranged Level Gas Drainage Roadway On Upward Mining Of Close Distance Coal Seam Group

Based on the study of the upward mining of close coal seam group at the time of the underlying multiple goafs,the top and floor damage rule,stress propagation rule,displacement variation rule and plasticity area evolution rule after multiple mining are summarized and analyzed.For the mine in the gas extraction roadway layout,protective strata mining and comprehensive management of gas to provide a theoretical basis and reference.Using a similar material simulation test and FLAC3 D to form a goaf after mining the next group of coal in a mine in Guizhou,the mining changes of the upper coal group were simulated.By simulating the multiple mining process of 16#,18# and 19# coal seams,the state of the underlying goaf is reduced.In the first design scheme,the gas extraction roadways are arranged between the 12# coal seam and the 16# coal seam,In the first design scheme,the extracting roadways are arranged between the 6# coal seam and the 8# coal seam.By simulating the layout of the extracting roadways and excavating the 8# coal seam and the underlying coal seam,the stress on the roof and rock movements were monitored.Analyze and compare different simulation results and initially determinescheme 1 from the perspective of roadway stability.According to the results of the study,it is shown that choosing gas extraction roadways at a height of 20 m from the 16# goaf and a horizontal projection distance of 20 m from the return-air roadway of the mining face is beneficial to the stability of the gas extraction roadway and the extraction effect is also improved.It has certain application value for the promotion and application of similar mines and safe and efficient mining mines with in our province.