The self drilling anchor bolt is mainly composed of a hollow anchor bolt, a drill bit, a coupling, a centralizer, a plate and a nut. The anchor bolt is a hollow bolt with a continuous full length external thread. The drill bit is installed on the end of the anchor bolt and is used for drilling rock layers or soil layers. The drill bit is disposable and will not be taken out after drilling. The coupling is a tubular part with an internal thread for connecting the SDA bolts. The centralizer has a ring shape, and the installation and the anchor bolt play the role of centering the anchor bolt in the drill hole, reducing the shock and simultaneously making the grouting around the anchor bolt average and full. The plate is a plate-like structure with holes and is mounted on the anchor body and pressed with a nut. The nut is used to press the pad and transfer the anchoring force. SDA bolt can be used for permanent support and advance support. Pressure grouting through hollow anchor bolt can achieve the purpose of consolidating broken rock masses, enhancing anchorage force, and separating groundwater and rods from corrosion.
