Self drilling bolt is a type of hollow anchor bolt, acting as drill rod and grouting pipe. The slurry sprays from drill bit through self drilling bolt to fill fracture and drill hole of the surrounding strata so as to solidify self drilling bolt and surrounding strata into a whole and thus play the role of reinforcement. Therefore self drilling bolt can be regarded as a new supporting technology integrating drilling, grouting and anchoring as a whole.
Self drilling bolt can be lengthened. The short anchor bar matching with the small drill rig can be suitable for the basement, bridge, river and narrow space. Currently self drilling bolt has been widely used in railway construction, tunneling, mining, hydropower station, dam, bridge base, foundation reinforcement of buildings. Furthermore, it is workable for the repair of ground subsidence, hole collapse, crack, landslip and other geological disasters.
Self drilling bolt was used for the slope stabilization of Beijing – Qinhuangdao expressway to reinforce the fracture rock. The fracture rock was swelled and spalled caused by rain erosion resulting in poor weathering ability and slope instability.
Finally the contractor adopted self drilling bolt and spray anchoring for the slope reinforcement and the anchoring effect has always been very good so far.