1. Arranging position of holes
Arrange holes on the surface of the initial shotcrete according to the requirements of design drawings.
2. Drilling hole and installing self drilling rock bolt
After excavation and initial shotcrete, the drilling should be started with the artificial hand-held pneumatic drill as soon as possible in the simple bench. When the drilling is finished, the self drilling rock bolt should be installed in time. In the plugging process, the anchor bar should be kept in the center of the hole. The length of the self drilling rock bolt exposed should not be greater than the thickness of the shotcrete. Then spray the concrete again to thickness designed on the drawings. In the watery region, the water in the hole should be cleaned or drilling should be operated in the near site. Finally, install the self drilling rock bolt.
The injection pump was adopted for grouting. The grouting pressure is 1.0Mpa~1.5Mpa. When grouting quantity in the single pipe reaches to the requirements of drawings, the grouting should be over.