Anchoring Method Utilizing Self-Drilling and Self-Anchoring Extensible Anchor Rod Applicable to Soft and Weak Coal Rocks

摘要

#$%^&*AU2017317603A120180614.pdf#####Abstract The present invention provides a self-drilling and self-anchoring extensible anchor rod applicable to soft and weak coal rocks and an anchoring method thereof, which are suitable for supporting soft and weak coal rock mass in roadways. The anchor rod body comprises five parts: a simple drill bit, intermediate rod bodies, connecting sleeves, a tail rod body, and a tapered rubber plug. In use, a hole is drilled with a drill rod to 1/4-3/4 designed drilling depth first, and then the anchor rod is assembled as required for drilling; when the last section of rod body is assembled and extended, the tail rod body is used instead of an intermediate rod body; anchoring force is formed by means of friction self-drilling coal and rock dust of anchor rod and quick shrinkage and deformation of the hole, and then pre-tightening is carried out; thus, selfdrilling and self-anchoring are realized; since the hole is formed semi-automatically, the construction workload is reduced, the construction time of a single anchor rod is shortened, and hole abandon incurred by hole collapse is avoided; the anchor rod body is a multi-sectional and extensible rod body, and the total length of the anchor rod body can be adjusted at any time according to the requirement in the field; no explosive cartridge is used, and a drawback of explosive cartridge insertion failure incurred by hole collapse and poor anchorage of explosive cartridge in the soft and weak coal rock mass is avoided.