Patent ID: 11959383
Assignee: TAIYUAN UNIVERSITY OF TECHNOLOGY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 3:
4. The method of claim 1, wherein after support of the return air gateroad is stabilized, the inlet air gateroad is excavated; four grouting holes are arranged in each row on a roof of the inlet air gateroad; the four grouting holes in each row are respectively a first grouting hole, a second grouting hole, a third grouting hole and a fourth grouting hole from a first side of the roof of the inlet air gateroad to a second side of the roof of the inlet air gateroad, the first grouting hole and the second grouting hole are both at an angle of 45° to the roof of the inlet air gateroad, and are inclined upward towards the first side of the roof of the inlet air gateroad in a parallel manner, so as to extend into the stoping coal seam below a floor of the return air gateroad; the fourth grouting hole is at an angle of 45° to the stoping coal seam, and is inclined upward towards the second side of the roof of the inlet air gateroad, so as to extend into the stoping coal seam below the floor of the return air gateroad; and the third grouting hole is perpendicular to the stoping coal seam at the roof of the inlet air gateroad.