Study On Gob-side Entry Driving In Three Soft Coal Seam And Fully Mechanized Caving In Xindeng Coal Mine

In order to reduce the driving of headings,lose mining replacement serious,solve the problem of the concentration of gas in forward corner and boosting coal recovery ratio,Xindeng Coal Mine adopting the inclined longwal,lroof caving coal mining method?However,thus results in some problmes,such as bolt support can not be used in roadway support,big range roadway loose,a roadway with dynamic pressure during deformation is difficult to avoid addition to the great mining height,large range of disturbance of surrounding rock and three soft coal seam?In this paper,based on the Specific conditions of 31061 fully mechanized caving face of Xindeng Coal Mine No.21 coal seam of Shanxi Formation,by using of theoretical analysis,,numerical simulation and the method of field testing and moindustrial test,the method of leaving lane along goaf to stay away from the effect of dynamical pressure have been proposed,caving mining lateral movement laws of overlying strata and the space-time change law of ground pressure have been studied,the time of gob-side entry retaining avoid dynamic pressure,support methods and technology have been verified and controlled.The results show that 15 m wall stress is low in the face of the rear goaf of fully mechanized coal caving face of Xindeng Coal Mine,15~70m stress gradually increased,stress decreasing zone appeared after the coal wall 70 m,the rock pressure phenomena with inclined longwalling is shown at the rear of the working face 30~40m is the stage of the slow increase of pressure,in the rear 40~70m range is a rapid increase in pressure phase,In the rear 70 m is a the pressure stable stage.Through the comparison of the currently method of gob-side entry retaining and the method of leaving lane along goaf to stay away from the effect of dynamical pressure,choose a suitable location to secondary roadway maintenance and roadside support,roadway deformation is mainly based on the relative displacement of roof and floor,the stress concentration position is still located inside the coal wall,the peak stress and without supporting basic is located in the same location.Far from the relief valve unit pillar pressure range value,but the pillar can not reach the maximum support capacity,making the pillar can not be cut in time,the condition of the mine can be used to strengthen the support of high strength support.