Modern Mining December 2015

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22 MODERN MININGDecember 2015
GEOTECHNICAL
How do you limit rocks from be-
ing dislodged from the upper
areas of degrading slopes in
open-pit mines? The answer is
simple … you cover the ‘guilty’
slopes of the opencast mine with a big ‘fence’.
This was the solution adopted at Orapa and it
allows the continuation of mining in areas that
were previously considered too unsafe to mine.
In 2013, Wepex, a specialist geotechni-
cal contractor based in Durban, South Africa,
partnered with global steel manufacturer and
supplier Maccaferri and consulting engineers
Melis & Du Plessis to undertake the rock-
fall mitigation installation at Orapa. One of
Debswana’s flagship opencast diamond mines,
Orapa was facing some challenges with rocks
falling down some of its slopes, particularly
during the rainy season. Situated 240 km west
of Francistown, Orapa is currently mining at a
depth of 250 m and is expected to reach 450 m
by 2026.
The project – known as the ‘Rockfall Support
of Orapa Mine AK1 Pit 805 Ramp and North
Eastern Ramp via Drapery Wire Mesh Support
project’ – addressed two areas of concern
on Orapa’s highwall pit slopes. Both high-
walls were above active haul roads that allow
Innovative solution to rockfall
Rockfall protection at
Debswana’s Orapa diamond
mine. Note the proximity of
the haul road.
Geotechnical contractor Wepex recently completed a
rockfall mitigation installation at Debswana’s Orapa
diamond mine in Botswana. The project recently received
a ‘Special Mention’ in the prestigious Best Projects Awards
organised annually by Modern Mining’s sister magazine,
Construction World. The following article is based on
the submission for the project entered into the Awards by
specialist supplier Maccaferri.