The Civil Engineering Contractor June 2018 | Page 17

ON SITE
The first of 96 piles being drilled into the soft earth. The piles are
various diameters, ranging from 500mm to 1.2m.
in the mix ensures that when the mix
leaves the nozzle and impacts with the
wall, it stiffens, or firms within about
20 minutes,” he adds.
Alford says that initially, the mix
contained stone, measuring 9–14mm,
but that changed. “While the finish
was okay, we removed the stone and
increased the sand content, resulting
in a much nicer finish, with the same
strength,” he explains.
Challenges
All three professionals agree that
while the weather creates a challenge,
it is the logistics that is the greatest to
overcome.
The proximity to busy roads
within a built-up area poses multiple
challenges, as there is the noise
component to deal with, compounded
by limited access to site, creating
little to no laydown area.
A ready-mix concrete truck gingerly negotiates its way down the
ramp after the extensive rains.
“We are at the early stage of the
design development, so we have
brought Solid Green on board to
advise us on how best to optimise
green building principles.”
Dev Devan, 3D Projects
Alford says: “The weather is a
challenge. However, with projects of
this size, the main issue is normally
logistics, because the earthworks
company needs to bring multiple
trucks on site, while we want concrete
on site and need a place to store our
steel and equipment. If tight sites like
this are not planned properly, it can
turn into a mess. Even the on-site
offices had to be removed once the
wall had reached its optimum height.”
He continues: “In addition, there is a
substation on the site, which created
a problem. Normally on sites like
this, that area would be kept open,
enabling us to erect a site office or
create a laydown storage area. But on
this site, we have gone down so deep
that we needed to take the stuff off
the top, namely, the site offices.
“Other than that, we are going well,
and we are ahead of schedule. The
earth is soft, which makes it easier
for us to drill; the trim is easier for
the Shotcrete; and the earthworks are
easier as there is no rock.”
“The main concern has been around
the extensive rain that has fallen over
a short period of time, waterlogging
parts of the site, bogging trucks down
in the mud,” Moonsamy adds.
Harrogate has 10 trucks a day
running backwards and forwards from
the tip site in Midrand.
Devan concurs and adds that the tight
programme also poses a challenge,
exacerbated by the vast amount of
CEC June 2018 - 15