The drilling of hydraulic anchor drilling machine adopts rotary drilling machine pressure water drilling method. Before drilling, the design, supervision, geology and construction units shall lay out the hole location according to the geological conditions on site

(1) After the drilling rig is in place, the vertical, horizontal and angular deviation of the hole position shall be corrected according to the design requirements, and shall be perpendicular to the retaining wall.

(2) The hole wall shall be straight to facilitate the placement of tie rods and grouting.

(3) In order to maximize the anchoring effect of the anchorage section, the hole wall shall not collapse or loosen, otherwise the placement of the pull rod and the bearing capacity of the soil anchor cable will be affected.

(4) It is forbidden to use bentonite circulating mud to protect the wall during drilling, so as to avoid the formation of mud skin on the hole wall and reduce the bearing capacity.

(5) Allowable deviation of drilling: horizontal deviation 50 mm, vertical deviation 20 mm, angle deviation 0.5 degree.

When the anchoring section of the drilling rig is anchored, the hydraulic reaming bit is replaced, and the water jet pressure is used to expand the hole diameter.