Research On The Technique Of Fully Mechanized No-Pillar Mining With Top Cutting Pressure-relief Gob-side Entry Retaining

With the exploitation of coal resources,mining intensity increased year by year,shallow coal seam is less and less,coupled with the progress of science and technology at home and abroad,many coal mines have entered the deep mining,thus,the roadway layout in the deeper strata,has become the inevitable trend.For a long time,The main way to protect the roadway is to keep the section coal pillar,in the process of coal mining,most coal pillars are left in the goaf,thus resulting in a great waste of resources,in addition,leaving the pillars will cause stress concentration,problem of ignition in goaf,thus it has seriously affected the safety production of coal mine to keep the section coal pillar,so these problems in the safe production process must be solved first,many domestic and foreign scholars have made unremitting efforts in order to overcome this problem,through theoretical study and field practice they have proposed the technology of cutting the top pressure with non pillar mining.The emergence of cutting top pressure relief can be regarded as a further innovation of the gob side entry retaining technology,Its application has improved the technology of non pillar mining,Through the practical application in the mine,this technology is the most advanced in all the non pillar protection technology,The application of this technology in Baijiao Coal Mine is a very successful example.In the process of gob side entry retaining,The conventional way of supporting cantilever will cause the goaf roof pressure influence greatly the effect of the roadway protection by roadway support body,This will cause severe deformation of roadway and even damage of roof.After the working face is broken down,cantilever beam will formed in upper and lower lane,in this paper,the mechanical properties of the cantilever beam are systematically studied,combined with the supporting way of the gob side entry,by pre-splitting ahead of goaf roof achieves the goal of cutting top,reduce the alley supporting resistance force and roadway support,and improve the surrounding rock stress environment.finally improve the stability of gob side entry.Combined with the practical application of the technology in No.8 coal seam and No.12 coal seam,and this technology is summarized...