Development of a new methodology for evaluating rock support performance in seismically active mines

Purpose and goal
The project’s goals were met. Methods (i) that relate seismic parameters to other factors affecting damage to rock and rock reinforcement, (ii) for evaluation of the rock reinforcement function through damage investigation, and (iii) to define the requirements for rock reinforcement in seismically active mines have been developed. Implementation of these methods will reduce the number of production disturbances, and thus the risk of personel injury, equipment damage and production loss.

Structure and implementation
The study included damage investigation, field measurements and analysis. Six seismic events in three Swedish mines have been studied using an innovative damage investigation method. Various types of instrumentation were installed in three Swedish mines. Four seismic events that occurred in or near the instrumentated areas have been investigated. The damage investigations and field measurement and monitoring data were analysed and integrated to develop a new method for evaluating the rock reinforcement function.

Results
The project resulted in

• a damage investigation manual that can be used to investigate damage caused by seismic events directly after a seismic event and to collect data on damage, geology and the properties of the seismic source.
• new methods for evaluating the function and efficiency of rock reinforcement systems in seismically active mines.
• new methods for numerical analysis of underground openings and rock reinforcement response to seismic load.
• a new rock reinforcement strategy for seismically active mines in Sweden.