Precursors to Rock Mass Failure in Underground Mines

Author: T. Szwedzicki

Analysis of documented case studies indicates that each rock mass failure is preceded by a precursory manifestation of rock mass behaviour. Structural damage and progressive failure is manifested by the presence of geotechnical warning signs (indicators and precursors) and can be exacerbated by triggers.

Indicators suggest that the rock mass may be prone to damage, whereas geotechnical precursors prove that the rock mass has been damaged and may precede possible failure. The failure process starts with a failure initiation phase, progresses through a propagation phase and ends up in rock mass collapse, rockburst, outburst or inundation.

Geotechnical analysis shows that the failures do not happen at random and are not unpredictable in terms of the type of failure and its location. Indicators and precursors have to be interpreted in conjunction with mine design, mining activities and potential triggers. Geotechnical monitoring of the precursory behaviour of the rock mass provides timely warning and allows for implementation of remedialv measures.