1)The self drilling anchor bolts should be arranged radially and evenly on the cross-section diagram. The arrangement will look like rectangle or rhombus on the engineering plan.
2)Relating to the direction of the self drilling anchor bolts, they should be perpendicular to the outlines of the tunnel in the whole rock strata while perpendicular to the surface of the rock in the bedded rock so as to the self drilling anchor bolt can function well.
3)The depth of the self drilling anchor bolt eyelet should be consistent with the construction requirement and the anchor bolt used in the project.
4)The rock grains, broken pieces and water should be blown out of the self drilling anchor bolt eyelet to ensure the anchorage quality.
5)To ensure that reliable anchorage effect of the self drilling anchor bolt. Generally speaking, the anchorage length is only about 200m which has good resistance capacity. The self drilling anchor bolt will has practical anchorage power when the plate is clung to the the rock surface and the nut is tightened.
