EMC EXPANDABLE ROCK BOLTS

Since the introduction of expandable rock bots to the market in the 80’s, this type of bolt has become a reference system in tunnel fortification and underground mining, thus gaining wide recognition for its reliability, simplicity and performance.

They are bolts consisting of a tube made of high elastic limit steel, bent over itself forming an omega shape and sealed at the ends with bushings. Moreover, once introduced in the rock drill, which must have a diameter lower than the original diameter of the tube, they are expanded by applying water under pressure, making them enter under load and offering immediate support, thanks to the action of two types of forces: a radial pressure perpendicular to its axis along its entire length and another friction force along its entire length.