A new methodology for the rock-burst assessment during tunnel construction
Risk associated to rock-burst occurrence in tunnels is nowadays managed by a continuous monitoring of acoustic emissions recorded during the excavation, whose characteristics depend on the failure processes ongoing in the rock-mass. A new in situ test was specifically designed with the aim of calibrating the alarm threshold for rock-burst occurrence. The test consists in compressing to failure a portion of the rock-mass at the tunnel side-wall by means of a couple of flat-jacks, measuring simultaneously the generated acoustic emissions with accelerometers.