Study On Surrounding Rock Control Technology Of Roadway Heading Face In Bailu Coal Mine

Face coal mining in the insufficient place,meet face excavation construction method is very effective,and in the surrounding rock stability of the roadway drivage face stoping face control is urgently needed to solve technical problems,in this paper,white reed coal mining face 4307 mining face,the 4308 working face of return air,transport gateway excavation as the research background,the numerical analysis by finite element analysis software FLAC3 D for different coal pillar width,excavating period 4308 working face in the process of the two mining face and return air,transport gateway deformation characteristics of surrounding rock,the relatively reasonable width of coal pillar in the section,The surrounding rock control technology of the 4308 returning air channeling tunnel and the 4308 transportation channeling tunnel has been determined and successfully applied in Bailu Coal Mine.The main research conclusions are as follows:(1)Determine the reasonable width of coal pillar 20?25m.The low stress zone is within 0?8m from goaf of 4307 working face;The original rock stress reaches5 MPa at 8m;The range from 8m?14m from goaf is the high stress zone,and the peak stress is 10 Mpa.It is 14m?25m from the goaf,and the stress gradually drops to7Mpa;The stress tends to the original rock stress slowly 25 m away from the goaf.(2)The leading supporting stress at the position 10 m from the front of the working face is relatively large,and the surrounding rock deformation and the supporting body stress are obviously increased.(3)The return air duct of 4308 is adjacent to the 4307 working face.In addition to the mining action of this working face,it is also affected by the mining action of4307 working face.The supporting mode is that the roof adopts left-handed spiral steel bolt,steel cable and H-shaped steel belt for combined support;the non-mining side USES left-handed spiral steel bolt,and the mining side USES fiberglass bolt.(4)The actual ore-pressure law of the backdraft tunnel was observed through industrial tests: in the period when the backdraft tunnel was tunneling into roadway,the deformation rate of surrounding rock(roof,floor and two sides)gradually decreased with the continuous advance of tunneling,and the deformation of surrounding rock gradually tended to be stable.During the 4308 backdraft channel service(stoping period),when the working face advances to the observation station,the surrounding rock movement corresponding to the roadway is the final movement.At this time,the movement of the roof and floor is 413 mm,and the movement of the two sides is 293 mm,which can fully meet the safety requirements of roadway use.There are 38 pictures,12 tables and 86 references in this article.