Franki Africa Supports the New
Webber Wentzel Building
Franki has received widespread acclaim for its foundation and general geotechnical work on the
60,000m³ Webber Wentzel Building and on a host of other significant basements in the Sandton area,
including Sasol’s new headquarters.
F
rom a geotechnical perspective,
Webber Wentzel’s new head office
was challenging. Of the total excavation of 68,000m³, no less than 17,000m³
was extremely hard blue granitic rock.
“This is very hard material which required
extensive drilling and blasting,” says Franki
project manager Paulo Alves. “But easily
the biggest challenge on this job was the
diabase dyke that we came across along
the Rivonia Road face when we were installing the soldier piles.
“This was unexpected and required a
completely different piling application and
technique, which entailed us replacing 40
(no) auger drilled soldier piles with 610mm
diameter percussion-drilled piles, which
took in excess of a month to install.
“This too was a tight contract with
respect to time and in this regard we were
put under pressure with the discovery
of the dyke. With the demolition of the
existing structure taking longer than
anticipated, access to the lateral support
and earthworks was limited.”
But Alves says the contract, which
started in June 2013 and was completed by
mid-November 2013, was still completed
in an acceptable time-frame. The scope
of works included: 68,000m³ excavation
to a depth ranging between 8m and 14m;
96 (no) 600 diameter soldier piles; 240 (no)
strand anchors and 250 (no) rock bolts and
a total gunite area of 2,900m².
Teamwork
Alves says that to complete the Sasol and
the Webber Wentzel contract in seven
months - two significant basements totalling 237,000m³ excavation and requiring
drilling and blasting and the installation of
hundreds of piles - was no mean feat and
one which could not have been achieved
without exceptional teamwork.
“Our team and our partners on these
jobs, Zero Unlimited Earthworks and ProFrag Blasting, went way beyond the call of
duty in order to get the job done professionally and on time. They often sacrificed
weekends and never complained about the
extra hours that were needed when the
pressure was on,” Alves says.
He adds that unless there is harmony
and teamwork between all the players on
complex geotechnical sites, all the expertise and experience in the world can mean
very little. “From our project managers to
the Zero and Pro-Frag on-site managers,
these jobs were shining examples of how
engineering and related teams can work
together to produce world class results,”
he says.
For both jobs Franki Africa utilised three
lateral support teams and two Soilmec SR
30 drill rigs, which proved to be invaluable
in the speedy and efficient drilling and installation of the soldier piles.
Part of the Keller Group
Meanwhile Franki Africa MD, Errol Braithwaite, says that acquisition of Franki by
the Keller Group a little over two years ago
has been a tremendous boon. “The Keller
Group is the world’s largest independent
geotechnical engineering contractor and
being part of an organisation like this has
had obvious and significant benefits for
Franki including access to a wide range of
innovative technologies, finance for growth
and, of course, a wealth of geotechnical
intellectual property and experience.
“In turn, Franki Africa has brought to
the group its vast experience in working
in Africa and this is helping to accelerate
Keller’s growth into mainly sub-Saharan
construction markets, where significant
growth fuelled by major infrastructure and
resource-related projects is expected over
the medium to long term.
“But those who are benefitting the
most are our clients who are now able to
get an even better all-round service from
us including the most effective geotechnical solutions the world has to offer,”
says Braithwaite.
Keller is the clear market leader in the
U.S., Canada and Australia, and has prime
positions in most established European
markets as well as a strong profile in many
developing markets.
Tel: 011 531 2700
E-mail: [email protected]
Installation of rock bolts along
the Rivonia Road face and final
gunite coat being applied
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