The Civil Engineering Contractor August 2018 | Page 20

ON SITE
An indication of the enormous size of the foundations.
High water table
The high water table was a challenge.
The tanks’ foundations required
excavating to a depth of 1.8m on
average and this was sufficient to
disturb the high water table. Ground
water, combined with rainwater,
meant that pumping was an almost
daily activity on site. Fortunately,
a wetland site is adjacent and the
wastewater could be pumped there
without difficulties. Water led
to further delays, says Johnson, as
excavation would uncover layers of
damp material unsuited to undercut.
“This did not conform to what the
geotechnical survey had predicted,
and we had to cut deeper and fill with
G6 and G7 and insert rock anchors
and piling. Some of this we were
18 - CEC August 2018
able to source locally and from our
own excavations, but more had to be
bought commercially.”
Addressing safety
“It’s a challenging brownfield
environment in which we have to
adhere to strict petrochemical
standards and safety controls. There
are two levels of standards at play
here: the basic statutory compliance
standards of South Africa which
are non-negotiable, and the higher
behaviour-based standards of a
multinational company that seeks
to drive and incentivise elevated
standards of safety behaviour.” To this
end, both Motheo and Chemie-Tech
have safety officials on site, and the
company has monthly safety awards,
as well as monthly prizes for the
‘Safety Person of the Month’, as
nominated and assessed by staff for
something extraordinary related to
health and safety.
“We have had an excellent safety
record on this site,” says Johnson.
List of professionals
• Client: Royal Vopak
• Contractor: Chemie-Tech SA
• Architect: Royal Vopak
• Civil engineer: Royal Vopak
• Quantity surveyor: Royal Vopak
• Earthworks professionals: Motheo
Construction Group
• Geotechnical (piling, wall retainers,
and more): Aurecon did the geotechnical
report prior to the commencement of
the project. nn