international
construction
october 2013
FALSEWORK & FORMWORK
26
Special solutions
A key challenge for falsework and
formwork suppliers is to help contractors
execute complex projects on a tight
budget, which often means providing a
bespoke solution using standard, modular
components.
Chris Sleight
reports.
A
rchitects may be fond of coming up with extravagant
and elaborate designs for everything from bridges to
skyscrapers, but the challenge for contractors is to execute
these complex schemes on time and on budget. It is an area where
suppliers can not only help with technical advice and specialist
design services, but also suggest ways to make the construction
process more efficient.
When it comes to falsework and formwork, this often means
providing solutions that allow complex and ever-changing shapes
to be constructed using standard components that are easy to
handle and modify on site.
Peri for example has seen its Variokit modular system being
used for construction of a steel composite bridge over the
extended Lanaye lock facility in Belgium, on the border with the
Netherlands. Although based on standard rentable components,
the formwork system has a complex function, acting as both a
movable carriage and a cantilever bracket.
The locks link the Albert Canal with Juliana Canal, a side
channel from the River Meuse. Construction of additional lock
chambers will quadruple capacity, and as part of this project, a
new 200 m long road bridge, with a 136 m main span, is being
built across the shipping channel.
The S-shaped, 15 m wide bridge has cantilever lengths of 4.5 m,
and these are being built using two Variokit composite formwork
carriages, while radially-arranged Variokit cantilever brackets are
being used for two 30 m long tightly curved approach structures.
The steel composite design involves first placing box-section
steel beams, which support the slabs that are formed using the
two Variokit carriages. The project involves casting the slab in 13
segments, from 8 m to 12 m long to a tight schedule, and the
formwork carriages were delivered pre-
assembled to reduce the time required on
site.
They move on heavy-duty rollers
which are mounted on supports on the
steel structure with 4 m spacings. Their
design features a longitudinal truss made
out of standard main beams. The lateral
units were designed to be adapted to
the specified bridge section, and the
system also helped with on-site safety.
For example, the tie suspensions of the
cantilever formwork were handled entirely
from above.
On both banks of the river, the bridge
alignment features two 90° bends –
complete with extremely tight axis radii of
almost 30 m respectively, and these were
built using Variokit cantilever bracket
units mounted on steel beams.
Special solutions
Despite the tight geometry,
formwork for the two 90°
bends on the approach to the
new Lanaye lock road bridge
were built using standard
Peri components.
