Research on the technology of goaf retaining by blasting under complex geological conditions

Aiming at the difficult problem of implementing blasting top cutting to keep roadway along gob under complex geological conditions in the main running channel of the working face of Yiqing Mine, the blasting theory is used to calculate that the radius of the crushing zone formed along the radial direction after blasting top cutting hole is 0.06～0.08m, and the developing radius of the fracture zone is 0.33～0.65 m. Key parameters such as cutting height, charge structure, number of perforations and charge amount of gob retaining roadway are determined, and reasonable and detailed technical plan of cutting roadway retaining roadway is formulated. Meanwhile, targeted technical plan of high-strength and stable gob retaining roadway is formulated according to the change of stress environment of the retaining roadway. With the increase of the distance from the working face, the deformation of the coal wall, the subsidence of the roof and the heave of the floor gradually decrease. The deformation of the surrounding rock of the roadway is in the safe value range, which can meet the needs of the safety production of the roadway.