ABSTRACT:
Seismicity and rockburst damage is a common hazard in deep underground mining operations all over the world. Most standard ground support schemes are not or only limited able to cope with dynamic loading caused by rockbursts. High-tensile steel wire mesh has proven its performance and suitability for the application in rockfall protection systems where the load is very similar to rockbursts. Since the boundary conditions in mining are different to rockfall barriers, quasi-static mesh tests with ground support boundary conditions were carried out in collaboration with the Western Australian School of Mines (WASM). With these results, it was possible to calibrate a numerical model based on the finite element software FARO. This software was especially designed, calibrated and validated by the Swiss Federal Research Institute WSL for highly flexible rockfall protection systems. After the calibration of the software, it is possible to simulate dynamic impacts into different ground support setups. The energy absorption capacity, the maximal deflection, the anchor forces and the failure mode for a case study are presented in this paper. It is planned to validate these results with dynamic tests at the dynamic testing facility of the Western Australian School of Mines (WASM).
1 INTRODUCTION
The primary ground support in underground mining operations without rockburst hazard mainly consists of weld mesh panels and friction bolts. By going deeper and deeper, the mines experience increasing seismicity and according rockburst damage. In order to cope with this hazard, especially designed rock bolts with better energy absorption and elongation capacity were introduced. However, in the area of surface support, the only strategy at the moment is to use thick, fibre or weld mesh reinforced shotcrete which tends to be expensive.
