The Civil Engineering Contractor August 2018 | Page 18

ON SITE
Here a foundation for one tank is complete and the tank itself is beginning to be built.
inside, and with a steel tank on top.
“In this instance we are using earth
materials to construct a foundation
for a 30-million litre tank. This is
very intricate and specialised work,
consisting of layers of bitumen and
HDPE interspersed with fine sand.”
The base consists of G2, with river
sand the filler. “There is an estimated
50 000m 3 total volume of cut for
the contract,” says Derick Shabalala,
commercial manager at Motheo.
“There is furthermore 6 800m 3 of
estimated G2 material used for the
A crane lays part of the tank in place.
16 - CEC August 2018
The noisy neighbours – Transnet’s depot.
construction of tank foundations
(compacted volume), an estimated 11
500m 3 of sand for the tank infills, 4
100m 3 of G6 for the tank bund wall,
and 4 500m 3 of G7 and G5 for filling
around the tank foundations, 2 600m 3
of concrete for the manifold area, and
234 tonnes of steel,” adds Shabalala.
This new construction methodology
has complicated the procurement of
materials, services, and skills from the
local community. Moodley highlights
that the main goal is to “assist black-
owned businesses wherever we can”.
However, on-site contract manager
Rodney Johnson describes the
single biggest challenge as being the
procurement of these earth materials
in sufficient quantity.
“With current usage, we require
500m 3 a day of G2 and river sand.
But we cannot get sufficient supply in
the region. The activities are so linked
that without G2, we cannot put in the
river sand, and without river sand we
cannot put in the foundation. It causes
a chain reaction.