Expandable Rock Bolt

The expandable rock bolt is made out of a thin-walled steel tube folded on itself. The expandable rock bolt is secured by injecting high-pressure water into the hollow cavity of the bar once it is inserted into the borehole. This process instantly strengthens and supports the structure by creating friction between the bolt and the borehole wall. It is composed of end sleeves, retaining rings, liquid injection ends and plates.

• Function: hanging, beam forming, slope stabilization, arch forming, internal pressure
• Application scenarios: hard rock mines, tunnels or emergency rescue

Our Features

• Quality: We focus on material selection and quality control to ensure our products are of superior quality.
• Fast: Our unique design and precision manufacturing processes enable fast and reliable expansion and anchoring, ensuring optimal performance and a dependable connection.
• Cost-effective: It has high anchoring force, stability, corrosion resistance, and longer service life.

Features

• Simple, safe and immediate rock support
• Easy and fast installation
• Full length immediate anchorage
• No harmful bonding agents (resin / cement)
• High performance in hard, fractured and soft rock

 

Working Principle

Install the anchor rod in the drill hole and inject high-pressure water. After the water pressure exceeds the elastic limit of the pipe material, the rod will undergo permanent plastic expansion deformation with the geometry of the drill hole, making it firmly embedded in the surrounding rock. In addition, when the rod expands, the anchor rod exerts a higher pressure on the surrounding rock mass, forcing the surrounding rock to generate strain, increasing the surrounding rock stress, and in turn, the surrounding rock also produces corresponding extrusion on the anchor rod. During the expansion, because its diameter become larger, there is a certain amount of shrinkage along the longitudinal direction, which causes the anchor plate to be pressed tightly against the surface of the surrounding rock, generating upward supporting force, thereby applying prestress to the surrounding rock.

 

Construction procedure

1. Drill the hole
2. Insert the rock bolt
3. Start the water pump to expand the rock bolt
4. Installation completed