Research on pre-cracking and pressure relief technology of the removal channel of the fully mechanized mining face of deep buried strong ore pressure
In the mining process of No.3 coal seam of Hudi Coal Industry,the mine pressure in the main roadway of the panel area is obvious.In order to optimize the construction technology of blasting top cutting,improve the effect of blasting top cutting and pressure relieving,and realize the goal of"no deformation"in the corresponding main roadway of the panel area on the working face of 1311(a-bove),Hudi Coal Industry implements the scheme of deep hole blasting top cutting and pressure re-lieving on the working face of 1311(above).According to the geological conditions of the site,the theoretical calculation is carried out,and the practical experience of blasting cutting the roof of the surrounding mine is used for reference.Finally,it is determined that the cutting angle of the removal tunnel of 1311(above)working face is 15°,that is,the construction angle of the cutting drilling hole is75°,and the inclined side of the coal pillar is 15°.It is determined that the opening hole position of the pre-crack is 1.0 m away from the coal wall of the removal tunnel,the starting position of the pre-crack hole charge is 1.8 m away from the coal wall,and the final hole position is 7.5 m away from the coal wall.When the blasting hole of the roof is constructed,a drill bit with a diameter of 65 mm is se-lected,and the drilling interval is between 1.8 and 2.2 m.The hole depth is 33 m,the sealing length is 11m,and the charge length is 22 m.The scheme has a certain reference significance for the blasting pre-cracking top cutting and pressure relieving in the surrounding mine with strong ore pressure and the mine with similar conditions.
blasting and roof cuttingrisk assessmentmine pressure monitoringblasting materialsco-nstruction technology
万方数据
维普
