Contractors World UK & Ireland Vol 4 No 4

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The rest were either used across corners (in-
cluding the 27 m-long MP250) or as raking props to
transfer the loads from the piled wall to concrete
thrust blocks mounted on the floor of the excava-
tion.
Groundforce technical sales engineer Roberto
Gelormini explains that because the corner-braces
and raking props were not oriented at right angles
to the forces acting on them, special connectors
were required to fix them to the Mega Brace waling
beam and concrete capping beam.
“We worked with Ian Black Consulting to
design steel shear studs that were cast into
the capping beam to transfer the shear
loads.”
Another challenge was the fact that some of the
props were to be oriented on a slope as well as at a
horizontal angle to the beam.
As Roberto explained, because the props cannot
articulate in two planes, special concrete corbels
had to be cast into the beam to allow for the slope.
The four raking props were braced against heavy
steel I-beams projecting vertically from massive
concrete thrust-blocks cast into the base of the ex-
cavation.
And three of the props forming
corner-braces were equipped with
mechanical lock-off to ensure they
provided the minimum stiffness re-
quired by the design.
The first props started to arrive
on site following completion of the
secant piled walls in February.
“Our close work with the
consulting engineer, plus our
ability to supply high-capacity props, meant
we were able to reduce the total number of
props supplied” says Roberto.
Groundforce used ‘flying’ props instead of rak-
ing props wherever possible as this reduced the
amount of obstruction in the excavation.
First ‘partnering’
This was Groundforce’s first major contract for
McAleer & Rushe; but Roberto hopes that its
success will ensure that it won’t be its last.
Darragh Greenan, contracts manager with
McAleer & Rushe commented:
“I found Groundforce to be extremely
professional to deal with during the design
stage. The continued onsite support
following their appointment was one of the
biggest benefits of choosing Groundforce. It
provided the site teamwith a level of support
that helped the installation, monitoring and
removal of the props to run smoothly.”
•
•
Some of the props were to be
oriented on a slope as well as at
a horizontal angle to the beam
Page 14 Contractors World UK & Ireland Vol 4 No 4
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