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CONSTRUCTION WORLD
MARCH
2015
PROJECT PROFILE – STEEL CONSTRUCTION
I
The reason for the
project
In 2008, Professor Lee Berger of the Univer-
sity of Witwatersrand (Wits) was using Google
Earth to look for possible fossil deposits in
the Cradle of Humankind. What caught his
eye was a near circular ring of trees, some-
thing that would indicate a possible cave
entrance or potential fossil deposit.
While the full nature and extent of the
dig have not yet been resolved, and might
still take decades, what is known is that this
is a significant find from a paleontological
point of view. The site of Malapa has yielded
two partial skeletons, a juvenile male and an
adult female of a new species called
Austra-
lopithecus sediba
. While there are several
other sediba individuals from the site there
are also remains of the animals that occurred
alongside these remarkable hominids.
From geological studies it is known that
the cave roof (which has since eroded away)
stood 30 – 50 m above the current deposit.
Indicating that the hominids and animals
collected in what is known as a ‘death trap’
situation. The animals would fall into the
cave and then die on impact or not be able
to get out, leaving behind full body remains.
What is also known is that the fossils have
been reliably proven to be about two million
years old.
Initial difficulties
Built environment professionals are in some
respects used to solving challenges that
stand in the way of progress. And if ever a
project presented obstacles to get underway
this surely must rate among the toughest.
The Cradle of Humankind is a World
UNESCO heritage site. Before anything can
be done in the area permission must be
obtained from SAHRA (South African Herit-
ages Resource Association).
Even for something as important
as this dig is, permission to disturb the
ground needs to be obtained. Any develop-
ment whether it is a farmhouse for a farm
owner or a temporary cover over the dig
needs a permit.
The farm upon which the site is located
is privately owned. Wits needed to put a land
owner agreement into place which provided
access to the researchers as well as permis-
sion to erect a structure to protect the site
itself. In this respect the landowners have
been great supporters of the work being
done at the Malapa site.
Design
Architect Krynauw Nel says: “If we want to
work with the environment, let it teach us
its lessons. Bio-mimicry is the process of
design where forms and processes found in
nature serve as a design model. The design
is inspired by natural site forms: leaves,
insects and spiders and particularly by the
Sediba
fossils first discovered i.e. the clavicle
and scapula.
“Our proposed structure was to have
no concrete footings (due to possible fossils
in the ground), and removable, should it
ever be required – leaving minimal traces.
It was clear that some steel structures would
be the answer. Tubular steel and bone
motifs seemed an obvious match and
circular sections could be curved to deal
with site restrictions.
“Particularly challenging was that final
rock positions for the leg footings would
only be identified during construction,
prompting a solution in which legs could
pivot and even ‘bend’ to accommodate
these positions. This was a special solution
that proved useful during construction.”
The main structural element is the oval
curved space-frame or ‘Toblerone’ truss onto
which the roof is constructed and fromwhich
INGENIOUS
Such was the quality of the steel
structure at the Malapa Fossil
excavation site, which was the overall
winner and winner of the Association
of Steel Tube and Pipe Manufacturers
of South Africa’s Tubular category at
Steel awards 2014, that Steel Awards
convenor, Spencer Erling, was prompted
to say: “It is surely the first time since I
have been managing the Steel Awards
process that the overall winner has
ticked so many boxes as to why
this project represents excellence
in the use of steel.”
INNOVATIVE,
INVISIBLE,