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CONSTRUCTION WORLD
FEBRUARY
2017
30
PROJECT PROFILE
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A structurally sound solution came in
the design of a hanging shutter. The critical
load combination for the structure happens
when the water is at its lowest point.
The shutter has been designed to function
normally without the need for water
pressure on the rear face of the unit. The
forces acting on each pedestal connection
on the anchor piles amounted to 665 KN,
requiring the web of the anchor pile to be
stiffened with gussets to prevent buckling.
Horizontal forces which tended to ‘push’
the shutter off the steel piles during casting
were mitigated by pre-welding a cleat to the
king pile prior to driving.
The specification for cope beam
structures to be cast in the dry, called for
clever construction technique in the use
of a de-watered shuttering system. Each
and every pour requires the design and
construction of a new seal to overcome
water and tidal challenges. A double skin
was used to trap water that seeped in
which was then channeled to a sump for
dewatering. Divers are required to tighten
and align the shutter at its base, and then
the pour must be perfectly timed to coincide
with the low tide. This means a fleet of
ready-mix trucks on site, ready to discharge
in order to stay ahead of the tide as it rises.
Stripping of the shutter was only allowed
once the concrete had achieved a minimum
of 35 MPa as the concrete element formed
a cantilever and needed to be able to
support its own weight. Once the concrete
was cast and the shutter stripped, a second
above tidal level cast was undertaken to
bring the quay up to its final level.
Corporate social investment
Ports all over Africa are experiencing high
cargo volumes, calling for greater capacity
to safely accommodate bigger sized ships.
As South Africa’s principal container port
generating more than 60% of revenue, the
Maydon Wharf infrastructure upgrade will
result in much needed increased capacity
for the country’s economic functioning and
growth, and will alleviate the congestion
currently experienced in the port.
The SSA JV team is proud to have
been part and parcel in delivering a key
development project for the client and
ultimately, the contribution to society, it will
make in employment opportunities
in Durban.
Throughout the project duration,
the drive for education and continuous
learning has remained resolute, even with
the economic downturn experienced in
the construction industry. Graduates from
the Go for Gold education to employment
initiative have undergone experiential
training and continue to be part of the
SSA JV team, providing them with the
necessary skills and mentoring for their
professional development.
The project has employed a significant
number people locally, and takes pride
in its commitment towards training and
mentorship, encouraging individuals to
increase their skills set and gain promotion.
In 2014, the SSA JV team were the main
contributors towards the Jirah academy, a
community based satellite campus, which
is now offering N1 to N3 level engineering
studies. The first mainstream engineering
learners graduated in November 2015.
This is an example of how the company’s
investment in educating people impacts the
future of young minds in Wentworth and
extended communities.
Environmental impact
Great care is taken to ensure zero harm to
the little marine life that exists in the port
through efforts in using biodegradable
grease on sheet pile clutches, and
biodegradable shutter oil and foam seals
for the shutters. No major incidents have
occurred to date.
The project has been and continues to
consistently achieve a score between 96
and 99% for the client as well as external
ECO audits. Also, SSA JV have recently
been recertified ISO14001 based on the
Maydon Wharf project. The CSIR does
bi-weekly monitoring during dredging
operations on the berths.
Health and safety
Working over water and in the tidal zone,
with piling various piling activities, diving
operations and heavy plant and machinery
all operating simultaneously in confined
work areas, the health and safety of the
team was an important aspect of the
works. Good working practice and constant
educational topics on safety were part of
the daily preparations on site.
The SSA JV team recently celebrated
1 500 000 LTI free hours in July 2016, a
commendable milestone for a project of
this complexity and nature.