ABSTRACT
Deterioration in rock mass conditions can pose various geotechnical hazards like uncontrolled rock mass movement (fall of ground, crown or protective pillar collapse), seismic activities, slope instability, and inundation or instability of backfill, mine tailings or waste rock. Deterioration in rock mass conditions may lead to mining disasters such as multiple fatalities, environmental damage and severe financial losses. A geotechnical disaster depends on mining geometry and the scale of mining operations as well as on in situ and mining-induced stress, structural features and rock mass strength.
Identification of mining geotechnical hazards shall be based on observations and monitoring of rock mass behaviour under mining-induced stress and on analysis of mining parameters. Various manifestations of rock mass behaviour as response to mining can be identified in all phases of mining activities i.e. during development work and during production. Mining failures are preceded by geotechnical indicators, warning signs and triggers. Case studies demonstrate repeatedly that observation of rock mass response and timely implementation of ground control practices can mitigate the effect of stress changes leading to damage.
Rapid and violent failures of large-scale geotechnical mining structures cause significant safety hazards, material damage and interruption to or even cessation of mining activities.
A variety of deficiencies may arise during the planning and design stages, and the most common are caused by incorrect siting of the development and by designing excavations of inappropriate size and shape.
Even with all the indicators and warning signs, mining companies seldom see the geotechnical failures coming. Even the most sophisticated and well-manged operations are frequently caught unaware by disastrous events – events that could have been anticipated and prepared for.
