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Category 4: Special Projects
Introduction
With the expansion of the port of Antwerp, a second
sea lock is being constructed in the Waasland-port.
This is the complex of docks on the left bank of
the river Scheldt. The works started on 24 October
2011, with the finishing date scheduled for 2016. The
“Deurganckdoksluis” is 500 m long and 68 m wide. It
is a huge undertaking. The construction involves an
enormous number of excavations, and huge amounts of
concrete and reinforcement steel.
Assignment
For the building of the concrete retaining walls, we
were asked to design a reusable steel formwork for the
bottom-part of the L-shaped retaining walls.
For the retaining walls on the side of the
“Deurganckdok”, the formwork needed to be 26.5 m
long, for the “saskolk” 25.5 m long and for the retaining
walls on the other side of the Waasland-port, 16.5 m
long.
Furthermore, for each formwork-length there had to
be 3 formworks available, while each had to be easily
transformable from a female formwork into a male
formwork. Since the concrete of the retaining walls had
to be made in parts of 20 m, the individual parts could
not move, so they were designed with male and female
parts that fit to each other.
Its clear that a classic formwork could not be used
because of the huge pressure of the concrete. To fulfill
the assignment as economically as possible, only three
formworks were made. These were assembled with
steel profiles and steel plates on the concrete side.
The formworks were assembled as female formworks
and in the cutouts “male fitting parts” were inserted and
firmly fixed. Each formwork is a 3D-frame of 16.5 m
(Waasland-port), onto which on one side a 3D-frame of
9 m (for Saskolk) and on the other side a 3D-frame of
1 m can be assembled (to become the longest formwork
for the “Deurganckdok”).
Moreover, on top of the formwork the necessary
platforms and stairs needed to be installed in order to
enable work on the reinforcement and the concrete.
Furthermore there was a limitation on the horizontal
displacements of a maximal 30 mm on the total
formwork of 26.5 m and we had to consider that the
steel formwork was supported on the sheet piling by
jacks and that the position of these jacks had to be
adjustable at random.
Application of Scia Engineer
The specific construction of these steel formworks
taught us that a complete 3D-model in Scia Engineer
was necessary. Scia Engineer made it possible to
calculate the 3D-frames in a global way in detail. The
exact positions of the jacks on the sheet pilings and
the side-profiles of the steel formwork had a significant
influence on the horizontal displacement in the middle of
the formwork under the hydrostatic pressure of the fresh
concrete. The 3D-modelling ensured that this influence
was monitored in detail, which made it possible to
design the side of the 3D-frame in an efficient way.
We had some freedom to design the frame behind
the steel plates of the formwork and because it was
important to tune the design to the position of the
working-platforms and stairs, it was a good thing that
we could easily adjust the geometry of the frame in the
Scia-model to evaluate the consequences.
Scia Engineer proved to be a high-performance tool in
addressing this.
Sea Lock Waasland-Port - Antwerpen, Belgium
Software: Scia Engineer
