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MEDUPI POWER STATION
POSES HUGE CHALLENGES
ESKOM INFRASTRUCTURE
Eskom’s power generation capacity will be significantly boosted when
the new dry-cooled, coal-fired power station’s six generating units
start to come on line towards the end of 2011 at an estimated total
project cost of R130-billion.
LARGEST OF ITS KIND 14.5-million tons of coal a year for the next Scaffolding was called upon to provide
Located on a 883 ha greenfield site at 40 years. A full environmental impact study innovative formwork solutions for the
Lephalahle in Limpopo province, the power was carried out through the Department of construction of the condenser slab and tie
station consists of six boilers which will each Environmental Affairs and Tourism (DEAT) beams for the second to sixth power
drive a 800 MW turbine. Once all six units and a licence was granted by the National generation units. Each condenser unit has
are commissioned, Medupi will have the Energy regulator. four corner columns constructed of concrete
potential to add between 4,200 and 4,500 rising up 20 m to support a 9 m square
MW of electricity to the national grid. It is INNOVATIVE SOLUTION REQUIRED concrete slab.
recognised as the world’s largest dry-cooled, Civil engineering and construction work is
coal-fired power station. well underway and formwork solutions are Two horizontal tie beams between all four
playing a serious role in the condenser columns on each condenser are required for
The Lephalale site near Ellisras was selected as section. Two condensers are required for increased structural strength and are situated
it is near Exxaro’s Grootgeluk coal mine, each generating unit for a total of 12 in all. approximately 7 m apart. To construct these
which has been contracted to supply up to Formwork specialist Wiehahn Formwork & tie beams, Wiehahn designed and made up
Huge columns dominate the Medupi site. Special Wiehahn structural steel support to 9 m x 9 m x 1.5 m deep top slab.
FORMWORK
MEDUPI POWER STATION
MAIN CONTRACTOR
Medupi Power Station Joint Venture
(a Murray and Roberts, Grinaker-LTA Civil
Engineering and Concor consortium)
Contracts manager
Adrian Steele
CLIENT
Crane-handled Quickshore Tower for safe access to 8 m high column. Eskom
eight sets of heavy duty brace frames in a shoring and crane-handled into position
cantilever position, allowing two sets per 18 m above ground level.”
column.
LIGHTWEIGHT SLAB FORMWORK
EIGHT METER HIGH SHORING For the slab base, SRZ walers and GT24
Wiehahn technical manager Pieter Potgieter wooden girders and a plywood soffit were
said the brace frames were crane-lifted into used with stop-ends 1.5 m deep. Wiehahn’s
position. lightweight, panel PERI DOMINO formwork
system was employed as it does not require a
“An access system was also designed using crane and is easy to handle. “The DOMINO
Wiehahn’s Quickshore heavy duty shoring system was deliberately designed to work as
system, eight metres high per unit, was crane a single-sided form, thereby eliminating the
lifted and placed on the already cast need for 9 m-long ties, which would
columns, cantilevering out on CB brackets definitely move,” said Potgieter.
that were fixed on two corners of the
columns. This allows the steel reinforcing to “The system was supported by props with
be fixed for the next concrete pour as well as the tensile loads going back into the soffit
making the arrangement of the formwork which was designed to take such a load.”
required much easier and safer to execute. Wiehahn is also involved in the formwork for
This procedure is then repeated for the next the construction of fifteen 3 m x 3 m
horizontal tie beam.” concrete tunnels, each 200 m long, which
carry electrical cables to the various units
“The tie beams are 1.5 m deep and 1 m wide within the overall power station.
Head Office 021 880 7777
with steel reinforcing.” The slab which forms Cape Town 021 907 2100
the foundation of the condenser at the top of LIGHTWEIGHT WALL FORMWORK Midrand 011 729 2300
the 20 m vertical columns is large, being 9 m The base wall and vertical walls of the tunnels Durban 032 533 9307
square and 1.5 m deep. are being constructed with Econoform panels Nelspruit 013 758 1521
Bloemfontein 051 433 3150
and Wiehahn deployed its PERI SKYDECK, a Port Elizabeth 041 463 1141
SPECIAL SUPPORT SYSTEM lightweight aluminium panel formwork George 044 878 0105
“For the top slab support a special bracket system which was the formwork solution best Polokwane 015 298 8511
and steel beam support system is used, on suited to the construction of the tunnel East London 043 731 2807
Richards Bay 035 797 5299
top of which there are mini purpose- soffits. In some instances the side walls and Rustenburg 014 592 2816
designed beam trusses pre-assembled and the soffit were executed in a single pour. Klerksdorp 018 462 1408
delivered to the Medupi site. These keep the National ☏ 0861 70 80
system as light as possible and allow for Contracts have been placed with Hitachi to www.wiehahn.co.za
easier placement. supply the boilers and Alstom to provide the
steam turbines. At R33.6-billion, these are the Authorised distributor
The shoring on top of the steel beam support biggest single contracts ever placed by
were all pre-assembled Quickshore standard Eskom.
