Study On Surrounding Rock Control Of Gob-side Entry Retaining In Steeply-inclined Thin Coal Seam

With the underground mining gradually turned deep,mining depth increasing,high gas ? coal and gas outburst mine increased.Nnder the influence of mining,the surrounding rock deformation and fracture will produce a lot of pressure relief gas.At the upper corner of the working face,the traditional “U” type ventilation is likely to cause its gas to be overrun.With the coal mining face where the continuous extension of the location,coal mining face gas emission increased more and more.The gas in the upper corner of the coal mining face not only restricts the further improvement of the production capacity and production efficiency of the excavation equipment,but seriously endanger the safety of workers in the face workers.Therefore,for high gas,coal and gas outburst coal mining face,the prevention of gas overrun in the return air flow has also become one of the many problems that need to be solved urgently.Gob-side entry in the economy and technology have great advantagescan achieve coal mining face “Y” type ventilation,it can solve the problem of gas accumulation and overrun.In this paper,based on the similar material simulation,theoretical analysis,numerical simulation and other methods on the basis of the secondary roadside retaining test and its observation program on-site mine pressure measurement research.The main research results are as follows:(1)n view of the geological conditions of the mine,the mining conditions and the serious deformation of the existing roadway along the roadway,the failure of the roadway support,the roadway support deformation and serious damage,put forward the road reinforcement support and roadside anchorage Gangue bag support program.(2)The amount of roof sinking is related to the support strength of the roadway and the mechanical properties of the rock formation.The higher the thickness of the roof,the smaller the roof thickness;The greater the thickness of the roof,the smaller the amount of roof sinking;The amount of roof sinking and the width of the roadway is proportional to the relationship between the greater the width of the roadway,the greater the amount of roof sinking.The anchoring force and the amount of the anchor of the roof bolt are in accordance with the double Boltzmann equation: y = y0 + A · +(frac /(1 + exp((x-x01)/k1))+(1-frac)/(1 + exp((x-x02)/k2)))fitting curve is obtained by fitting the anchoring force and the amount of the roof.(4)-38402 Face during a stay stay,according to the three anchor anchors of the station,the stress of the roof can be divided into four zones: slow change zone,significant change zone,violent change zone and basic stability zone.The average rupture position of the roof in the side of the roadway is 4.9m.(5)-38402 Face during a stay stay,according to the relative displacement of the top and bottom plates of the six observation sections of the three stations,the law of the deformation can be divided into four zones: Slow change zone,significant change area,violent change zone and basic stability zone.Under the influence of the pre-support pressure and lagging support pressure of the-38402 working face,the roof of the 3882 working face was contracted by about 7.1% during the field mine pressure observation.(6)Through the analysis of the cost of the secondary roadway along the roadway,the secondary roadway along the roadway saves the cost and support cost of a roadway,the support cost is small,and it has significant safety technical benefit,resource benefit and environmental benefit.