True triaxial experimental study on hard rock under high geo-stress condition based on excavation and support

This paper presents a true triaxial experimental method to study the complicated evolvement of stress load, which produced by excavating and support underground engineering under high stress conditions. The experimental results show that the resilient deformation is occurred and acoustic emission counts rate is evidently enhanced when unloads the least principal stress. The enhancing extent of acoustic emission counts rate increases with the intermediate principle stress. The constitutive relation is elastic-brittle. The peak value of strength increases with the intermediate principal stress. The peak value of acoustic emission counts rate depends on stress state.