As a new construction technology, hollow anchor bar has been widely applied in hydroelectric station and it has overcome several technical difficulties in loose rock conditions. In high slope supporting construction of hydroelectric station, hollow anchor bar overcomes the difficulties of forming hole and hole collapse, etc. And it realizes the primary stabilization combining with jetting cement and drainage hole method, which accumulates experience for further application of hollow anchor bar.

Because of special structures, hollow anchor bar has following advantages:

1. High efficiency: Self-drilling hollow anchor bar combines drilling, grouting and anchoring together, several processes can be done at the same time, which is time-saving and high-efficient.

2. Suitable for stratum which difficult to drill hole: When encountering loose and broken surrounding rocks, it is difficult to drill hole and easy to collapse; while self drilling rock bolt can overcome this situation. After drilling hole, anchor bar still stays in the hole, which ignores collapse, saves time and reduce construction difficulties.

3. High adaptability: There is whole thread on the surface of self drilling hollow anchor bar, it can be cut at any position. So it is suitable for different construction conditions.

4. High anchoring force: The thread of self drilling hollow anchor bar divides into R-thread and T-thread. They can both connect with coupling tightly and have good bonding effect with grouting slurry.

5. Good anchoring effect: When grouting, slurry is from the bottom to orifice, the effect is full and dense, grouting quality is good.


6. Simple to construct: Compared with common rock bolt, self drilling hollow anchor bar has decreased the processes of pulling out of hole, installing anchor bar and inserting grouting pipes, which is quick and simple.

In a word, hollow anchor bar has played a crucial role in high slope of hydroelectric station. It has obvious features, such as single rock bolt has big tensile pulling force, great depth and small project amount, it is suitable for different geological conditions. Adopting hollow anchor bar to construct project can control or reduce the occurrence of rock burst, enhance ability of anti-seismic and control deformation effectively.