MEVA technology has been used to reinforce flood defences in Vienna

The reservoirs on the section of the River Wien flowing towards Vienna, just before the capital, have recently been modernised. Over the past decade, increasing attention has been paid to the management of natural water bodies: whilst water retention is important in agriculture, the protection of populated areas has also taken on a key role due to extreme weather conditions – as reported in MEVA Zsalurendszerek Zrt. website.

Across Europe, flood protection projects are being carried out one after another, aimed at renovating and expanding existing infrastructure. In the project carried out in the Auhof area, a few kilometres west of Vienna, there are densely built-up areas on both banks of the Wien River, where the river is flanked by a railway line and residential areas.

The nearly 120-year-old embankments here have been renovated and raised over a length of approximately 1,750 metres. The capacity of the existing Auhof reservoir has also been increased, meaning it will be able to discharge even greater volumes of water in future.

8-metre-high walls and heritage-listed access bridges

The walls, built at the beginning of the 20th century, were reinforced with a new shell wall constructed using single-sided formwork and concrete, in accordance with the specifications for waterproof concrete. As part of the project, a wall approximately 1,250 metres long and up to 8 metres high in places, as well as several weir sills totalling nearly 500 metres in length, were constructed.

What makes this project unique is that some of its elements are listed as historic monuments, so two old steel walkways were also renovated whilst retaining their original structural elements.

Formwork hire, cost-effective

GLS Bau und Montage GmbH, the contractor responsible for the works, used the MEVA Mammut 350 wall formwork system for the formwork of the tall, thick walls. Thanks to the system’s high load-bearing capacity, it is able to withstand the pressure of the fresh concrete across its entire surface, which is particularly important for walls several metres high.

This not only helped to ensure safe working conditions, but also sped up the pace of construction. The contractor used the formwork system on a hire basis, which ensured predictable costs throughout the entire duration of the project.

The construction of the walls without tie-ins required special technical solutions. The formwork elements were secured using double U-sections, whilst stability was ensured by anchors embedded in the existing structure.

A particular challenge was securing the single-sided formwork, which stood up to 8 metres high, to the old, in places porous concrete, as well as the varying angles of inclination of the walls. The formwork plans were drawn up by the experts at MEVA, and, combined with the contractor’s experience, ensured the successful completion of the project.