In
order to maintain biodiversity in the animal world, it is essential for most
fish species to reach their spawning grounds repeatedly, even if they must
overcome difficult conditions such as strong currents or flooding in the
waterways. To assist with this, an enormous fish ladder was built on the Upper
Rhine, at the EDF hydropower plant near Marckolsheim in Alsace, where formwork
and shoring systems supplied by the full-service provider PASCHAL from Steinach
were used for the concrete work.
The
contractor was DEMATHIEU BARD CONSTRUCTION from Metz (Agence Lorraine). The aim
of this project is to ensure that all fish species living in the Rhine use this
new ladder and that the river is revitalised for salmon species. The fish
ladder is divided into two circuits, a hydraulic circuit and a fish circuit.
The fish circuit consists of an attraction flow on the left bank, another on
the right bank, successive pool runs, a counting station and a fish outlet. The
hydraulic circuit begins with a water inlet, followed by a pressure pipe and a
micro power station on the right bank. A pumping station was also built on the
left bank. An area of no less than 3,000 m² was required for all the different
parts of the project, with the fish circuit having a total length of 1.0 km. A
height of 13.00 metres is bridged in the process. 8,000 m³ of concrete and 700
tonnes of structural steel were processed.
The
excavation work, mainly against sheet piling, was begun in July 2023 and the
entire project was completed in March 2025. PASCHAL had the task of forming
round walls, supporting high single-sided formwork and making difficult
formwork-related adjustments to existing structures or shoring.
The
variable radius circular trapezoidal girder formwork was on site for all the
circular walls, which had already been pre-rounded at the factory for the first
forming cycle and was therefore ready for immediate use without the need for
pre-assembly on site. The LOGO.3 wall formwork, with its well-balanced assortment
of panels and large-size panels, was ideal for long and high walls, as were the
small panel dimensions, including plastic filler pieces for complicated floor
plans. Costly additional shuttering on site was therefore avoided. The narrow
panel widths could also be used together with outside corner posts as column
formwork, eliminating the need for separate column formwork.
According
to site manager Arthur Rudolf, single-sided walls with a formwork height of up
to 8.00 metres were a particular challenge. But PASCHAL had a system solution
ready here too, because the standard 4.00 m support jacks can be underpinned
with two differently sized base extensions, so heights of 6.00 m or even 8.00 m
are possible. PASCHAL also provided the necessary structural analyses and
details for secure anchoring in the floor slab. "We have been a PASCHAL
customer for a long time and were once again able to rely on PASCHAL at this
construction site to always have technical solutions ready and respond quickly,
even with challenging formwork tasks," says site manager Arthur Rudolf.
Project
financed by France Relance and Next Generation Eu
