Search this website

Project Overview

Project Number
Total Grant Value
MRIWA Contribution
Project Theme
Engineering in Highly Stressed and Complex Rock Masses
Project Period
2018 - 2023

The Challenge

Rock bolts are subjected to complex loading conditions in underground mines with axial, shear and combined loads (axial and shear). Establishing the behaviour of in-situ rock bolts by testing and monitoring with fibre optic sensors to develop improved models and design of rock bolt support systems.

Key Findings

  • Under combined load conditions: 80% of the rock bolt axial load capacity should be assumed for the rock bolt design.
  • However, in situations with large shear, this is further reduced to only 50%. For both conditions, if the displacement percentage is higher than 80% then the rock bolt selection should be reconsidered (i.e. low-stiffness bar).
  • FLAC3D pile elements underestimate shear deformation in the case of localised high shear stress as found in a rock bolt installed across a joint. The modified pile model can simulate the correct shear response of rock bolt and combined axial and shear load failure of the rock bolt at joints and discontinuities.
  • Optical instrumented rock bolts provide a very high-resolution strain profile of the rock bolt installed in-situ.

Benefits to WA

Continuous improvement in the design of rock bolts and associated support system may lead to improved safety outcomes in underground mining operations in Western Australia. A new and improved instrumented rock bolt was designed for underground testing and software development which enables strain values to be monitored.

Keywords: rock bolt; underground; shearing

Similar Projects

Page was last reviewed 27 February 2024

Back to main content