Every year in North America, dedicated pile
driving rigs, drilling rigs and cranes tip over
or experience near misses due to issues
involving inadequate working platforms.
These preventable incidents often involve serious
injuries or fatalities to operators and ground crews,
and extensive damage to equipment. Despite the
importance of safe, stable working platforms and
the dire consequences that can result in their
absence, there are currently very limited guidelines
or regulations in North America for the design,
construction and ongoing maintenance of safe
working platforms.
Exacerbating the issue, due to increasing
demand for bigger structures that require more
intricate, deeper and larger-diameter foundations,
deep foundation construction equipment has
become larger, heavier and more complex to meet
these needs. As well, less desirable sites with very
poor soils are now commonly developed.
“Although this type of rig is typically stable
when tracking over a firm, dry surface, if the
underlying subgrade has insufficient bearing capacity,
under certain adverse loading conditions, this can
cause stability issues due to either deformation or
even failure of the underlying subgrade material,”
wrote Paul A. Gildea, P.Eng., a senior director of
Langan International and co-chair of the Working
Platforms Industry-Wide Working Group, in the
Spring 2019 edition of the ASCE News. “Even
something as relatively small as a one-squaremetre
soft spot can be sufficient to unbalance a
rig/crane and cause it to topple over.”
In a 2014 article for the International
Association of Foundation Drilling (ADSCIAFD)’
s Foundation Drilling magazine, James
Finbow, HSEQ manager at Bauer Foundations
Canada, wrote, “As an industry, we are continually
seeking solutions for … challenges and we
usually step up to the plate, but we seem to
have missed one key part of the equation: the
working platform.”
However, in recent years, the topic of safe
working platforms has experienced growing
attention in the North American market. Finbow
says that he believes there has been a change in
people’s perception and understanding of what a
working platform is and what the industry needs
to do to make work sites safer. The ANSI A10.23
drilled shaft safety standard has been recently
updated to include more robust language regarding
working platforms.
FEATURE
PHOTOS COURTESY OF PAUL GILDEA
PILING CANADA 35