Research And Application Of The Reasonable Position Of The Mining Roadway Under The Strip Coal Pillar

It is very important to study the reasonable position of the mining roadway under the strip coal pillar for increasing the stability of the mining roadway,reducing the waste of resources and realizing the safe production of the working face.Based on the research background of Jinqiao Coal Mine in Jining Shandong Province,this paper systematically studies the stress distribution law and plastic failure range of the strip coal pillar,and determines the reasonable layout range of the rail transport roadway in 1310 working face.Through the similar material simulation experiment and numerical simulation software,the mining conditions of coal pillars in different width sections are simulated,which provides the basis for determining the reasonable width of coal pillars.The field monitoring in 1310 working face verifies the reliability and rationality of the position of the track roadway and the width of the section coal pillar determined in this paper.(1)According to the plane strain theory of elastic mechanics,elastic-plastic theory and slip line field theory,the analysis and mechanical model calculation are carried out for the bottom and right goaf of the remaining strip coal pillar.The stress concentration area at the bottom of the strip coal pillar presents a bubble like distribution,which shows that the central stress concentration is serious and the stress concentration degree is weak within 10 m of the bottom edge of both sides.The bottom coal and the bottom coal within 11.9 m of the upper goaf of 1310 The floor is seriously damaged and the surrounding rock is loose and broken.(2)Through similar material simulation experiments,it can be known that after mining on the working face 1310 and the working face 1308,the roof pressure in the two goafs is low,and the stress at the bottom of the strip coal pillar near the edge of the goaf in 1308 is low.(3)According to the overlying rock movement during excavation of a similar material model,it can be known that when the width of the coal pillar is set to 5m,the goafs on both sides of the coal pillar are compacted at this time,and the floor pressure on the sides of the goafs on both sides rises,and the coal pillars are supported The pressure is reduced,no plastic failure occurs in the entire coal pillar,and the coal pillar can maintain a good supporting effect.(4)Through the numerical model analysis of the working face under the strip coal pillar,it can be seen that when the width of the coal pillar is 5m during the mining of the working face,the plastic damage in the coal pillar still has a good bearing capacity;the distributed stress in the coal pillar is greater than the initial stress,but the stress concentration is not large;the deformation of the surrounding rock in the rail transport roadway is small,and the maintenance of the roadway is easy.(5)Based on the industrial results of the 1310 fully mechanized top coal caving face,the research results are used for industrial experiments.By monitoring the roadway deformation amount,advanced support pressure and lateral support pressure,it can be seen that the roadway deformation is small and easy to support.Fully mechanized top coal caving face under coal pillar is safe and efficient.