In mining, a geotechnical hazard refers to risks associated with ground movements that can impact the stability of the mine and surrounding areas, potentially harming personnel, infrastructure, or the environment. These hazards can arise from natural phenomena or mining activities and include issues like landslides, rockfalls, subsidence, and slope failures. Effective management of geotechnical hazards is crucial for ensuring safety and operational success in mining.
Geotechnical hazards in open-pit mines primarily involve risks associated with the stability of the rock slopes and walls of the pit. The major types of geotechnical hazards are:
Unplanned rock slope movements and rock falls: these are sudden collapses or falls of rock from the pit walls, posing significant risks of fatalities, serious injuries, damage to infrastructure, and costly production stoppages.
Slope instability or deformation: this can be surface strain damaging infrastructure or catastrophic collapse affecting personnel and operations. Such failures are influenced by factors like slope geometry (angle and height), rock type, geological discontinuities, seismic activity, water inflow, and blasting practices.
Water-related hazards: inflows from groundwater or rainwater accumulation can weaken slope stability by saturating rock masses or causing erosion. Proper water management including drainage design is critical to mitigate these risks.
Structural geological hazards: these arise from rock mass characteristics such as faults, joints, bedding planes, and rock strength variations which can control the formation of unstable blocks within the pit walls and may trigger failures.
Operational hazards: these include risks from blasting vibrations, handling of ore and waste, and the presence of abandoned workings beneath or near the open pit, which can affect ground stability and worker safety.
In summary, geotechnical hazards in open-pit mining revolve around maintaining the stability of pit slopes against rock falls, slope failures, and water infiltration effects. Effective risk management includes good geotechnical investigations, careful slope design, monitoring of slope conditions, and site-specific control plans for slope stabilization and water management.
