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CONSTRUCTION WORLD
MARCH
2016
PROJECT PROFILE
Material decisions
Murray & Roberts Infrastructure conducted its own geotechnical tests to
enable it to optimise use of the material available in close proximity to
the project. “By doing this we were able to determine the most suitable
material from each area for use on the hard stands as well as on the
various road works that formed part of our contract,” Venter says. Cut
and fill quantities were balanced accordingly.
The project had significant quantities of hard rock and Venter says
that the construction programme also had to take cognisance of these
difficult excavation areas. Blasting had to be done for 30 of the 35 base
excavations due to the rocky ground conditions on the site.
Significantly all material excavated on site was reused on the
contract and depending on material specification this was either as fill
on the roads or hard stands or for backfilling of the foundations on the
wind farm site. In addition to this, three different areas were located
on site with material that was considered suitable to crush for wearing
course. Bedding material was also supplied for the trenches. The only
material imported was the concrete aggregate.
The decision for Murray & Roberts Infrastructure to erect a batch
plant to service this project was strategic and facilitated ready access
to concrete, as and when required. The plant is located on a farm adja-
cent to Noupoort.
The readymix being produced uses AfriSam OPC and includes fly
ash content facilitating a lower carbon footprint for the construction
and a reduction in cost. In total 20 000 m
3
of concrete will be used for
the construction of the foundations and ancillary structures.
Road works
The wind farm site is spread across three different landowners’ prop-
erties and it was necessary to construct access roads that would firstly
allow construction to take place and secondly facilitate the delivery
of all the wind turbine components for installation. Construction of
these roads required mass earthworks and cut to fill operations. The
road width is approximately 5 metres with a side drain for storm water
management. This gravel road scope of work also included the provi-
sion of cattle grids between the different landowners’ properties on the
boundary fences.
Maintenance of a 10 km section of the Oorlogspoort Road from
Noupoort to site was necessary. Part of the Murray & Roberts Infra-
structure scope of work included modifications at Cradock and the
Oorlogspoort/N9 intersection to accommodate the deliveries of the
wind turbine components. The blades, nacelle and hub are imported
and shipped the Port of Ngqura, in Port Elizabeth and then transported
to site, whereas the tower sections are manufactured locally, in Atlantis,
in the Western Cape. The locally manufactured turbine tower sections
mean that Noupoort Wind Farm has been able to achieve local content
commitments exceeding 40% of the project’s total value.
Environment and community
Before construction activities began, Murray & Roberts Infrastructure
subcontracted an environmental consultant to conduct a search and
rescue on the flora and fauna in the immediate locality. While no endan-
gered species were identified, steps were taken to relocate all vulner-
able species to areas with similar habitat and climatic conditions.
Around 230 individuals from the local community were employed
on the contract, and these ranged from general labourers up to machine
operators. Murray & Roberts Infrastructure places an enormous focus on
training, both in terms of competency and safety, and this was provided
at all levels, with certificates of competency issued.
The company has also continued its strong focus on supporting
the local communities and in a joint initiative with Mainstream, Murray
& Roberts Infrastructure has started a programme to upskill a local
contractor to repair the roofs of local buildings.
Jerome Govender, executive chairman of Murray & Roberts
Construction, comments that he is very pleased with the progress on
the project considering the weather and other challenges that had to be
overcome, and with the approach adopted with the environment and
the community.
The hard stand areas were cleared and grubbed and rock fill
brought in to level the area after compaction of the in-situ material. This
was followed by the addition of wearing coarse material which was also
compacted to give its final surface finish.
Venter explains that load bearing testing was done on each hard
stand to ensure it is capable of carrying the mobile crane’s weight
during wind turbine erection.
A completed hardstand at Noupoort Wind
Farm awaiting erection of the turbine tower.
Steel reinforcement for one of the concrete
bases at Noupoort Wind Farm.
A completed concrete base and plinth before
backfilling at Noupoort Wind Farm.