What is Self-drilling Anchor Bar?
Self-drilling anchor construction technology is a new type of anchoring technology developed in recent years, which is suitable for various complex geological conditions and construction site environment. Self-drilling anchor construction realizes the integration of drilling, grouting and anchoring functions, with simple construction process, high construction efficiency and good anchoring effect, and no need to worry about collapsing holes, which is widely used in slope, dangerous rock, deep foundation pit support, tunnel support and other projects.
The self-drilling anchor consists of six major components: hollow anchor body, drill bit, connecting sleeve, spacer plate, nut and centering device. The hollow anchor body is made of seamless steel pipe of high tensile alloy steel, with tensile and yield strength to meet various complex geological conditions according to the design requirements; the drill bit is made of wear-resistant metal casting with slurry outlet hole, and different models are selected according to the geotechnical conditions, such as "spherical tooth type drill bit", "cross type drill bit", etc. According to the processing technology, there are all-steel drill bits and alloy drill bits; the connecting sleeve is a rod extension part, which is of equal strength with the matching hollow anchor body. The nut and spacer are used together to transfer the anchoring force from the hollow anchor body to the spacer, and the spacer then applies the anchoring force to the surrounding rock, which improves the end force and enhances the anchoring effect of the self-drilling anchor; the centering device ensures that the self-drilling anchor body is always located in the center of the borehole during the construction process, thus ensuring that the slurry is of uniform thickness around the body and further enhancing the anchoring effect.