Mining Technology And Pressure Behavior Law Of Adjacent Coal Seam And Working Face In Xinyuan Coal Mine

This paper takes the No.8 and No.9 coal seams of Xinyuan Coal Mine as the research object,on the basis of the mechanical parameters of coal samples,according to the on-site investigation,and using the thickness relationship between No.8 coal seam,No.9 coal seam and gangue layer,puts forward a reasonable coal mining method in Xinyuan Coal Mine.On the basis of on-site investigation and mechanical test of coal and rock,the FLAC^3D numerical simulation is established to establish the mining model of 9103,3204 and 3205 working face.Combined with the field measured data of 9104 working face,the law of mine pressure behavior of 9104working face is analyzed.The main research results are as follows:（1）through on-the-spot investigation,underground sampling and coal sample testing,the coal samples taken from No.9 coal seam of Buxinyuan Coal Mine are tested.The density of coal isρ=1490kg/m³,the elastic modulus is 2.65GPa,the compressive strength is 6.88MPa,the Poisson’s ratioμ=0.20,the tensile strength is0.38MPa,the angle of internal friction is 35.30°,and the cohesion is 3.99MPa.（2）According to the mining investigation of No.9 coal seam in Xinyuan Coal Mine,the coming pressure law of 9101 and 9103 working faces is analyzed.through the mining experience of the above two working faces,it can be seen that the key factor affecting the safe and efficient mining of No.9 coal seam is the thickness of gangue between No.8 and No.9 coal seam.It can be known that the reasonable mining mode of No.9 coal seam in No.1 mining area is mainly abandoned mining No.8 coal and only No.9 coal.It is considered that it is more appropriate to adopt large mining height in the first mining area,and 4.0m high mining height is used.（3）The numerical simulation mining models of 9104 face,3204 face and 3205face are established,and the mining pressure behavior law of working face near 9104face is studied.Through the numerical simulation analysis of the stress distribution of the surrounding rock of the working face and the measured data of the mine pressure of the 9104 working face,the law of the mine pressure behavior of the working face is analyzed.（4）9104 working face is located under the coal pillar area of overlying No.3 coal seam,the force of the support（83#～120#）is small,and the pressure of the working face is not obvious.The phenomenon of broken roof,sloping coal wall and non-roof of support occurs frequently,which brings great difficulties to the roof management of working face.The pressure of the support column is generally up to the opening pressure of the support safety valve of 43.5MPa when the support is pressed,which shows that the working resistance of the support is obviously insufficient,and the working face is easy to be crushed,so it is necessary to select the hydraulic support with greater working resistance.