Soil nail is a kind of supporting technology in geotechnical engineering. It drills surrounding rocks with a certain distance, direction and depth, then it is put into the drill hole and at last, grouting and fixing are carried on. Soil nail has the effect of binding, combining and reinforcing surrounding rocks. It helps to improve rocks’ self-intensity and self-stability, lighten self-gravity, ensure safety and stability of projects.

1. Drilling.

(1) Before drilling, workers should fix a position and make a mark according to design requirements and stratum conditions.

(2) Working places should be flat, solid and have drainage ditch.

(3) After drilling machine in position, it should keep stable. The guide rod or vertical shaft should keep correspondence with the dip angle of soil nail and stay at the same axis.

(4) The equipment of drilling can choose special anchor drilling machine or geological drilling rig according to stratum conditions.

(5) During process of drilling, workers should master drilling parameters and drilling speed, avoiding the appearance of burying bolt or stuck bolt. Once accident occurs, salvage equipment is necessary.

(6) After drilling, clean water should be used to wash the bottom of anchor bolt until it returns out of orifices.

2. Installing.

(1) Making soil nail at the center of drill hole and settling isolating tray on the bolt.

(2) The rust on soil nail should be cleaned and the free segments should be packed by plastic pipes or cloth.

(3) Preventing the distortion or bend of soil nail. Grouting pipe should be put into hole with bolt and about 50-100 millimeters to the bottom of hole.