YIELDABLE ROCK FASTENER SYSTEM AND METHOD

摘要

A yieldable rock fastener system has a pre-stressed seven-strand cable bolt grouted inside a borehole in a rock face of a mine or tunnel. A steel sleeve is press-fitted onto the cable bolt either outside the rock face or inside the borehole. When the sleeve is external, the sleeve is designed to yieldably slip relative to the cable bolt under a load exceeding a predetermined threshold force induced by a rock burst or other rock displacement. When the sleeve is internal, the sleeve is grouted inside the borehole so that the cable bolt yieldably slips relative to the internal sleeve when the predetermined threshold force is exceeded. The yieldable rock fastener system thus absorbs and controls rock bursts and other rock strata movements, thereby inhibiting cave-ins and collapses.