In tunnel projects, with increasing of tunneling length, the problem of roadway support becomes prominent, which becomes one of four big factors restricting tunnel’s safety production (other three factors: water’s threat, gas’ s threat and stress of production alternation) and should be solved now. All kinds of
anchor bolts and their combinations have become the main current of tunnel support.
Practice has proved that
hollow anchor bolt is one of the most common used method in tunnel construction. It’s simple, low cost and reliable anchoring technology.
Hollow anchor bolt adopts good thick-walled seamless steel pipe as material and combines functions of drilling, grouting and anchoring together, which is easy and convenient to operate, saves time and workload, shortens project’s period.
High-effect grouting fills cracks, solidifies rock and soil, and controls underground water, which has good grouting diffusion radius and reliable anchoring quality.
With strong penetrating drill bits, hollow anchor boltcan drill all kinds of rock.
Hollow anchor bolt doesn’t need to pull out, it can be used as grouting channel and grouts slurry.
Plug can keep strong grouting pressure, fill cracks adequately and fix broken rocks. Plate and nut can transmit stress to surrounding rocks evenly and achieve the goal of surrounding rocks and hollow anchor bolt support each other.