Mine Pressure Regularity Of 110 Method And Its Influence Mechanism On Gas Emission Of High Gas Mine

Based on the theory of "short cantilever beam by roof cutting" proposed by Academician Manchao He,the formation of the roof-cutting and non-coal pillar self-forming roadway mining technology—110 method,not only improves the recovery rate of coal resources,but also solves the problem of mining company's mining replacement.The 110 method was known as the third industrial revolution in the coal mining industry,China's traditional coal industry has made a qualitative leap in technology.At present,it has been successfully applied in many mining areas,from thin coal seams to medium-thick coal seams and thick coal seams,from composite roofs to broken roof to hard roof and from shallow burial to deep burial..." 110 method" has been used in various geological conditions successfully.However,there are only a few applications in high gas mines,and research in related fields is almost blank.This paper takes the typical high gas mine,Shanxi Coking Coal Group Xishan Coal Electricity Group Co.,Ltd.Du'erping Coal Mine as the engineering background,comprehensively uses theoretical analysis,numerical simulation and on-site monitoring to systematically analyze the key technical parameters of 110 method,stress field distribution characteristics of working face,law of mining pressure behavior and mining pressure zoning of working face and roadway,roof deformation characteristics,etc.,and based on these conclusion,researching the effects of front abutment pressure,periodic pressure and roof deformation on coal seam gas emission in "110 method".At the same time,the distribution law of gas concentration in gob and the law of air leakage in gob are analyzed under the condition of Y-type ventilation system.The specific research contents are as follows:(1)Through the on-site investigation of the geological conditions of the test face,with the help of numerical simulation software and the successful experience of other mines,the key technical parameters of the "110 method" of the 62711 working face of Du'erping Coal Mine were determined,including the depth,angle and spacing of the presplitting blasting borehole,the reinforcement support scheme of NPR constant resistance large deformation anchor cable,and get the best blasting method and the best charge were obtained by field test.(2)By comparing with the "121 method",the front and lateral stress distribution characteristics of the working face in the "110 method" were researched.The results showed that the vertical stress in front of the working surface paralleling to the direction of the working surface increased firstly and then decreased and tended to be stable,and it showed that the stress of uncut side>the stress in the middle of the working face>the stress of cut side.On the side of the working face,the stress concentration area transferred to the deep part of the coal mass,and the pressure relief area formed within a certain range of the roadway.(3)Taking the 72909 working face under the condition of "121 working method"as the comparison,the numerical simulation and field monitoring method were used to study the law of mining pressure of the working face and roadway in the "110 method".According to the distribution characteristics of the mine pressure,the working face was roughly divided into four areas along the direction of inclination:the stress increase zone in the end of uncut side(I zone),the unaffected zone in the middle of working face(? zone),the stress increase zone in the cut side(III zone),and the end pressure relief zone in the end of cut side(IV zone).The roadway section was divided into four areas along the direction of the work surface:pressure relief zone,dramatically behavior zone of dynamic pressure,influence zone of dynamic pressure,and roadway stability zone.(4)Through the analysis of the deformation characteristics of the roof strata in the"110 method",with the help of numerical simulation software combined with field monitoring data.Contrasting and analyzing the height of water flowing fractured zone of the working face in the "110 method" and "121 method",the results show that the height of fractured zone of the working face in the "110 method" is obviously smaller than the height of fractured zone of the working face in the "121 method".(5)The influence of the front abutment pressure on the coal seam gas emission in the "110 method" was studied,as the front abutment increases,the permeability of the coal seam will decrease.In the "110 method",the influence area of front abutment of the working face is less than the influence area of front abutment of the working face in the "121 method",so it is more conducive to the drawing out gas based on coal order in front of the working face.(6)Gas emission was sharply increased during periodic pressure,compared with the "121 method",the periodic pressure in the "110 method" was lower,the cyclic weighting interval was larger,resulting in a decrease in the gas emission from the working surface and a decrease in the frequency of the gas concentration on the working face.(7)Through the monitoring of gas concentration and O2 concentration in the gob,the distribution of gas concentration in the gob and the law of air leakage in the gob with the "110 method" are analyzed and summarized.The field monitoring results showed that with the using of "hanging curtain" and "spraying" methods in the 62711 working face of Du'erping Coal Mine to seal the gob,and cooperate with the original gas drainage system,the problem of gas accumulation in the gob and air leakage in the gob under Y-type ventilation conditions was well solved.It had provided successful experience for the application of "110 method" in the high gas coal mines.