Hollow grouting anchor itself doubles as a drill pipe and grouting tube for blowing dust before grouting tube, both rule out the the drilling formation of dust, grouting slurry ejected from the drill bit through the hollow bolt, fill in the blank anchor around the drillholes and stratigraphic fissures, the anchor and the surrounding soil solidified into one to form the steel pipe concrete pillars, played the role of reinforcement.
Bolt axial force, the stress state of the rock mass surrounding rock in a certain range into a three-way one-way (or two-way) compression pressure, thereby increasing its ring to the compressive strength, compression with either under its own weight, but also to withstand the external load, making it effective control of the surrounding rock deformation.