Rock properties to predict rockburst vulnerability in three dimensions

The Challenge

Unpredictable rockburst and strainburst events create significant safety hazards for mining personnel and operations, however these phenomena are poorly understood. 

The challenge for this project was to understand the influence of rock properties on the proneness to strainburst. 

The Solution

For the first time, this research has enabled direct measurement and understanding of in situ stress, 3D rock properties (static and dynamic), influence of rock fabric and anisotropy, extensional strain in 3D, field observations of bursting, fractography, disking and borehole breakout, and unravelling of support structures around bolts. 

The additional measurements can be obtained from oriented drillcore, enabling cost effective development of new strategies to improve design and safety solutions for mining operations. 

The process of determining the in situ stress led to development of a 3D extensional strain approach using a fully compliant orthotropic strain matrix that can be used in regular 3D numerical modelling software. 

Benefit to WA

This research makes a significant contribution to mine safety, hazard awareness and opportunities for improvements to bolt behaviour. 

Keywords: in situ stress, 3D rock properties, 3D extensional strain, biaxial loading, bolt performance