Carlton, R, Darlington, B & Mikula, PA 2013, 'In situ dynamic drop testing of the MD bolt at Mt Charlotte Gold Mine', in Y Potvin & B Brady (eds), Proceedings of the Seventh International Symposium on Ground Support in Mining and Underground Construction
, Australian Centre for Geomechanics, Perth, pp. 207-219, https://doi.org/10.36487/ACG_rep/1304_13_Mikula
The MD bolt has recently been trialled at Mt Charlotte Gold Mine. Static in situ load testing has demonstrated high anchorage capacities for the MD bolt in this rock mass, but it was not certain how the bolt would perform in dynamic conditions. Therefore a series of drop tests were conducted on bolts installed underground. This was done by suspending a one tonne mass on chains below the test bolt, and then allowing it to fall through 2.1 m before transferring kinetic energy to the bolt at the collar. A high-speed video camera was used to remotely obtain the time–displacement record for each test.
The results showed that for the test conditions in this rock mass, the MD bolt will slip along the borehole during a dynamic loading. Bolt slip ranged from 23 to 503 mm per impact, and calculated bolt forces applied to the bolt ranged from 40 to 105 kN. This testing provides confidence that the bolts do have significant dynamic capacity, and can be utilised accordingly within ground support schemes at the mine.
Heal, D. and Potvin, Y. (2007) In-situ dynamic testing of ground support using simulated rockbursts, in Proceedings Fourth International Seminar on Deep and High Stress Mining (Deep Mining 07), Y. Potvin (ed), 7‒9 November 2007, Perth, Australia, Australian Centre for Geomechanics, Perth, pp. 373–394.
Krois, L. (2011) Maximum innovation, safety and productivity – the MD Bolt introduction at the Fosterville Gold Mine, in Forum notes ACG international Forum on Safe and Rapid Mining Productivity Development, 24 March 2011, Canberra, Australia, Australian Centre for Geomechanics, Perth, CD-Rom only.
Mikula, P.A. (2012) Progress with empirical performance charting for confident selection of ground support in seismic conditions, in Proceedings Sixth International Seminar on Deep and High Stress Mining (Deep Mining 2012), Y. Potvin (ed), 28–30 March 2012, Perth, Australia, Australian Centre for Geomechanics, Perth, pp. 71–89. Also in Mining Technology: Section A, Maney Publishing, Vol. 121, Number 4, 2012, pp. 192–203.
Mikula, P.A. and Lee, M.F. (2000) Bulk low-grade mining at Mt Charlotte Mine, in Proceedings MassMin 2000, G. Chitombo (ed), 29 October to 2 November 2000, Brisbane, Australia, Australian Institute of Mining and Metallurgy, Melbourne, pp. 623−635.
Potvin, Y., Wesseloo, J. and Heal, D. (2010) An interpretation of ground support capacity submitted to dynamic loading, in Proceedings Fifth International Seminar on Deep and High Stress Mining (Deep Mining 2010), M. Van Sint Jan and Y. Potvin (eds), 6–8 October 2010, Santiago, Chile, Australian Centre for Geomechanics, Perth, pp. 251–272. Also in Mining Technology, Vol. 119 (4), pp. 1–13.
Sandvik (2010) Sandvik Mining and Construction Australia, viewed 29 January 2013, www.miningandconstruction.sandvik.com.au.