Stress Distribution And Displacement Variation Characteristics Of Soft Coal Seam In Front Of Mining Face

Well working is the main characteristics of coal production in china, Pre-extrtaction is an important technical measure to achieve mining of coal and gas and effectively prevent gas disaster in coal face.However,with the extension of mining depth,the distribution of soft coal seam has been expanding.As the soft coal seam is high gas content and low permeability.it has been difficult and key for the coal seam gas extraction.How to increase the permeability of coal to effectively increase gas extraction rate of the soft coal seam is a serious problem.In this paper,permeability of coal is extremely sensitive to the stress based on the more extensive understanding and analysis of previous studies;"Pressure relief antireflective"technology is to improve the soft low-permeability coal seam gas extraction rate in an effective way.Therefore,to difine the stress distribution and variation of coal mining face is critical.Stress distribution and displacement variation in front of the face are analysised by ANSYS;The stress distribution and displacement variation of the coal top and bottom layer at different distances from the face are discussed;Initially identified the distribution and formation mechanism of strong deformation zone and fractured zone in front of the face.The vertical stress values of the top layer and the bottom layer at different distances from the face are measured by borehole stress-meter,and on the basis, to respectively obtain the corresponding vertical stress curve. By the analysis and discussion,with a view to targeted for different distances and different horizons of soft coal seam in fornt of mining face,a more effective"pressure relief antireflective"technical measures are expected to provide a theoretical reference,and explore new ideas about futher promoting and perfecting gas extraction theory of the soft and low-permeability coal seam.