Rockburst prevention using a novel de-stressing method

Abstract

De-stressing is a common rockburst control measure used in deep mines and tunnels. The benefits of using the de-stressing method to control rockburst have been demonstrated by its successful implementation. However, rockburst remains a threatening phenomenon in many deep underground excavations. Herein, a new de-stressing method for rockburst control is proposed. In this method, the rock is de-stressed by cutting notches at the excavation boundary. First, a circular tunnel is modeled and the stress distribution around the tunnel is then calculated. Thereafter, a notch was placed at the tunnel wall in a different model. The results revealed that when the notch was introduced to the model, the rock at the tunnel wall de-stressed, and the stress concentration zone moved far away from the wall. Additionally, an analysis of the failure zone around the tunnel and the velocity of the failed elements revealed that the failure of the notched tunnel was less violent than that of the tunnel without notches. Finally, a parametric study was conducted to investigate the influence of the notch length on the de-stressing process around the tunnel. The modeling results indicated that the proposed de-stressing method could be used to control rockburst in deep underground excavations.