| This paper chose the low-index outburst of soft coal seam,a special type of outburst as the research object,took the heading face of Ⅱ1-21010 machanical roadway in the mining area of the west of Henan Province as the research background,studied theoretically the low-index outburst of the soft coal seam,focusing on the Launch and development mechanism of coal and gas outburst was researched,the effects of geostress,gas pressure and physical properties of coal on the outburst mechanism were mainly analyzed.Comparative study on the width of the limit equilibrium zone and the deformation of the surrounding rock,the stress distribution and so on,studied systematically the outburst prevention technology according to the research conclusion,and designed the relevant outburst prenentive measures,the main research results were as follows:(1)Analyzed the influencing factors of the mechanism of the low-index outburst of soft coal seam,and classified the low-index outburst.(2)The relationship between the outburst danger of the soft coal seam heading face and the limit equilibrium zone was established.The larger the limit width is,the greater the risk of outburst is.On the contrary,the smaller the risk is.(3)Through the numerical simulation and comparison,it was found that the softer the coal,the greater the risk of coal and gas in the process of coal roadway excavation.With the increase of the thickness of the coal seam,the danger of outburst also increases.Under the same conditions,the coal and gas outburst hazard of roadway driving along the top of the soft coal seam is less than driving along the bottom.(4)Research on the technology of outburst prevention measures showed that risk of outburst can be reduced by strengthening roadway support and selecting reasonably roadway arrangement,And then narrow the scope of the plastic zone and reduce the stress concentration degree.So that reduce the risk of outburst of heading face. |
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