e-mosty September 2018 Vessels and Equipment Used for Bridge Construction | Page 45

Figures 5 + 6: Lifting of sections
Transportation, load-out and lifting of the removable
span – equipment and operations
ALE supplied 168 axle lines of SPMT to perform the
load-out of the heaviest section: the removable span,
a simply supported deck which measured 150m long
and weighed 4,000t.
700t counterweights on the viaduct and connected it
to the longitudinal beams with a swinging system to
avoid any additional horizontal loads.
The other pier, Pier 10, was set up in a similar
configuration. However, to maintain stability, a
transverse beam was installed behind the three
longitudinal beams with 500t capacity strand jacks
fixed to anchorages onto the pier´s base.
To start lifting the 4,000t removable span, ALE needed
to perform the barge ballasting. Starting at low tide,
the span was gradually loaded-out on the four lifting
points using 168 axle lines of SPMTs.
During this manoeuvre, ALE had to consider any
potential changes in the stability as the SPMTs moved
across the deck.
Figure 7: Sea transportation of the removable span
After this load-out, the final operations consisted of
lifting and shifting the deck using complex steel
structures and strand jack units HLS8500, with a total
lifting capacity of 6,800t, whilst controlling the
ballasting of the barge where the whole section was
transported.
Once the weight had been transferred to the strand
jacks at Pier 10 and lifted 2m, the span was tilted to
5% elevation, to match its final alignment, and
continued until it was positioned at its final elevation.
It was then moved transversely by 2m using eight
push-pull units to skid along the track placed on the
top beams of the lifting structures.
The equipment was installed on each of the two piers,
with Pier 9 housing two lifting points and two pairs of
two 850t capacity strand jacks. When it was in its final position over the bay, ALE
lowered the deck and adjusted it longitudinally using
12No. 90t-capacity push jacks.
The strand jacks were installed onto the transverse
beam placed above a three-beam longitudinal
cantilever and supported by a transverse bea