Table 2 The common classification standard for rockburst intensities6.
From: Rockburst intensity grading prediction based on the LOF-ENN-KNN model
Rockburst label | Failure characteristics |
|---|---|
None rockburst | There is no sound of rockburst and rockburst activities. |
Light rockburst | The surrounding rock is spalled, cracked or striped and there is no ejection phenomenon and a weak sound. |
Moderate Rockburst | The surrounding rocks are more severely deformed and fractured with a considerable amount of rock chip ejection, loose and sudden destruction, accompanied a crunchy squeak which often appears in local cavern in surrounding rock. |
Strong Rockburst | The surrounding rocks are severely bursted and suddenly thrown or shot into the tunnel, accompanied by strong bursts and roaring sounds, air jets, the continuity of storm phenomena, and rapid expansion into deep surrounding rocks. |
