Friction bolt (Split sets) is a frictional ground support system.When friction bolt is inserted into drilling hole with smaller diameter,
the slot partially closes and bolt diameter is compressed, which creates radical forces on rock roof surface along the whole length and firmly holds the rock.
1. Outer diameter (mm): Φ30, Φ33, Φ40, Φ39, Φ43, Φ46, Φ47 (±0.5);
2. Length (mm): 450, 900, 1200, 1500, 1800, 2000, 2500, 2800, 3200, 3400.
3. Material: Q235, 16Mn, 20 Mnsi.
4, thickness 2.0-3.0
Install the pipe anchor in a bore smaller than the pipe diameter. At this time, three forces will be applied to the surrounding rock. One is the radial pressure on the hole wall over the entire length of the pipe anchor. One is friction to prevent the surrounding rock from falling, and the other is the bearing force of the pipe-stitched pallet pallet. These three forces make the surrounding rock more stable.
l, the raw material is made of high-strength alloy strip;
2, the installation is the simplest;
3. No anchoring agent is needed;
4. The friction between the anchor and the rock mass is large;
5, has a high shear and tensile strength;
6, equipped with high-strength tray, the tray is evenly stressed;
7. The height of the roadway is greater than the length of the bolt.
1. The surface of the seam pipe anchor should be flat without serious strain and rust. The weld shall be free of cracks, no slag inclusions, and shall not be allowed to burn through the pipe wall. The tray should be free to move on the shaft. It is advisable that the retaining ring interface and the slit opening are mutually offset from 170o to 190o.
2. The pull-out force of the retaining ring weld is ≥80kN, the ultimate tensile strength of the rod body is ≥110kN, the initial anchoring force is ≥25kN/m, and the bearing capacity of the pallet is ≥65kN.
1. Initial anchoring force: 3~7 tons;
2, pipe loop pull-off load: 8~10 tons;
3, anchor pipe tensile and breaking capacity: 12 ~ 13 tons;
4. Corrosion resistance is 20~30% higher than A3 steel, which is beneficial for long-term use.
1. Determine the hole position of the anchor rod according to the design requirements, and punch the hole with the drilling machine.
2. Use the pressure wind to blow out the rock powder in the hole.
3. Install the anchor plate on the rod body and use the impact drill to drive the anchor rod into the hole.
Recommended calculation method for borehole anchor hole drilling aperture:
In the rock formation: bore diameter = (0.9-0.95) × bolt diameter
Bolt drilling depth: bolt length +100mm borehole slope <1%
In the coal seam: bore diameter = (0.9-1.00) × bolt diameter
Bolt drilling depth: bolt length +200mm borehole slope <1.5%