A new Minerals Research Institute of Western Australia (MRIWA) report has been released that establishes the behaviour of in-situ rock bolts with fibre optic sensors.
It is hoped that the report will aid in developing improved models and designing improved rock bolt support systems.
In the project, extensive laboratory testing sought to understand rock bolt behaviour under complex load conditions.
Physical models were prepared to simulate the shearing in underground openings with the results used to analyse the effect of combined load on the safety factor of rock bolt reinforcement in underground openings using numerical modelling.
A significant reduction was found in the actual safety factor of the reinforcement designed under combined load conditions.
A new instrumented rock bolt was designed for underground testing. To analyse the data, a new software tool was written, allowing the operator to observe the recorded strain values for a single fibre or for one rock bolt at a time through a graphical user interface.
The software also provides the option to display the 3D shape and deformation of the bolt.
The MRIWA report M0499 further summarises the findings of the research.