EMC EXPANDABLE ROCK BOLTS
The expandable rock bolts are a stabilization device for rock masses in mining and underground works. They are made up of a high elastic limit steel tube, bent into an omega shape, and sealed at the ends with ferrules.
Once inserted into the hole drilled in the rock, which must have a larger diameter than the original diameter of the tube, they expand through the application of water under pressure. This process causes the anchoring bolt to be loaded, and offer immediate support. This is achieved thanks to the action of two types of forces; the first force- a radial pressure perpendicular to its axis along its entire length, and the second force- a frictional force along its entire length.