EQUIPMENT
56
Groundforce
international
construction
december 2013
T
he private apartment block under construction at Chêne-
Bourg in the suburbs of Geneva, Switzerland, will not –
by the time the first residents have moved in by late 2014
– appear any different from the many others surrounding it.
If unremarkable in appearance, what does single it out as
something a bit different is the technique used to support the
deep excavation during construction – a set of 16 hydraulic
shoring struts in two layers stretching across the 26 m wide site.
These massive struts – 0.61 m in diameter on the bottom layer
and 0.51 m on the top – support the 12 m deep excavation over
its full 80 m length and are being used in place of traditional
temporary steel frame shoring. It is the first time that the
Swiss contractor Implenia has used the system and also its first
application in Switzerland.
Jean-Pierre Binétruy, geotechnical engineer and project
manager at Implenia’s foundations division, told
iC
the
company normally favours the tried and tested structural steel
frames, in part because they know how to do it that way, but
also because it already owns the steel.
Cramped conditions
At Chene-Bourg, however, space is at a premium, with the
site bounded on one side by a busy road and on one of its
long edges by an existing apartment building. So cramped, in
fact, that the project offices have to be cantilevered over the
excavation.
So Implenia decided to try out hydraulic struts, a system
that it first saw at a foundations exhibition in Piacenza, Italy,
in 2012 where it was being displayed by Groundworks, the
trenching equipment division of UK rental company VP plc.
Groundworks, which rents an array of trenching, shoring
and piling products as well as the more sophisticated hydraulic
struts, worked with Implenia and civil
engineering design engineer ESM &
Fiechter Ingenieries to come up with a
design for the project. This comprised
two sets of eight struts, the lower
struts using Groundforce’s 250 tonne
capacity MP250 units and the upper set
comprising smaller, 125 tonne capacity
MP125 units.
All 16 run in the same direction, with
spacing between each pair to allow for
lowering of formwork and other building
materials.
Something
different
An unassuming apartment block project
on the outskirts of Geneva is helping UK
rental company Groundforce introduce
its hydraulic shoring technology to
the European market.
Murray Pollok
reports from Switzerland.
Sixteen shoring struts, in two
layers, span the 26 m wide site
along its full 80 m length.
A slab being
poured from a
concrete pump
parked along
the edge of the
cramped site.
Jean-Pierre
Binétruy, project
manager at
Implenia’s
foundations
division.
