Supporting projects are the very important link during the whole construction. They belong to security technical measures and they have good effect on anti-collapse. Different locations should be designed according to different geological conditions, structures, sizes and methods. There are two methods for supporting: framework support and rock bolt support.
Rock bolt is one of important supporting materials in preventing roof fall in mining project, its quality relates directly to safety production.
Grouting rock anchor is an effective supporting method. It can adopt various kinds of steel tube, as for material of self drilling rock anchor, there are basic requirements.
1. High strength.
The higher of self drilling anchor’s tension, the smaller of prestressing force’s loss ratio.
2. Better plasticity and processing performance.
Self drilling rock anchor needs to keep prestress for a long time, it’s optimal that self drilling anchor has high strength, at the same time, it has little relaxation losses, which demands prestressing tendon has enough plasticity. During construction, prestressing tendon can produce bend inevitably and will get higher local stress.
3. Good corrosion resistance.
Especially for permanent self drilling rock anchor, its material needs better corrosion resistance. Good capacity of corrosion resistance determines that self drilling anchor can suit for special construction conditions, such as: undersea tunnel, harbor, etc. Compared with common rock anchor bolt, self drilling rock anchor with good corrosion resistance has certain resistance to air, water and chemical reagents. So, it has longer life, generally can reach at about 120 years.
4. Small dimension error.
It can guarantee product’s precision and be easy to control prestress.