News

Warbud engineers will rebuild the road bridge over the Warta River in Kostrzyn nad Odrą. The contract was signed on 16 July 2021. The document was signed on behalf of Warbud by Mr. Zenon Kozdrowicki, Deputy Production Director. The project is implemented out by Państwowe Gospodarstwo Wody Polskie, with the support of the company Sweco Polska Sp. z o.o. as a Consulting Engineer. The project is financed  by International Bank for Reconstruction and Development (World Bank) and the Council of Europe Development Bank, with the support of the Cohesion Fund and the state budget.

The purpose of the project is flood protection of the inhabitants of the Odra basin and the upper Vistula basin and modernization of the road infrastructure. The task implemented in the build formula ("red" FIDIC) is scheduled for completion in 2023.

Scope of the project

Under the contract, Warbud will dismantle the existing road bridge and built a new structure in its place which will be 300 meters long with better load-bearing parameters. The new structure will be located higher above the water table, thanks to which barges or icebreakers of larger dimensions will pass under it.

To maintain the continuity of road traffic, our engineers will build a 240 m long temporary bridge and maintain it throughout the construction period. It will be a Bailey-type structure, i.e. a kind of portable steel truss bridge designed during World War II for military engineering units. The road system, including conflicts of underground utilities within the access roads to this bridge will also be rebuilt.

Structure of the new bridge

The final bridge is a three-span structure with an overall length of 300 m. The main span is 150 m long. It is an extradosed bridge combining the idea of a suspended structure and prestressed beam structure (box section entirely made of concrete).  In bridges of this type, some prestressing cables are led abobe the piers (outside the girder cross-sections) which, made in the form of low pylons, perform the function of the so-called deviators. The span lengths of this type of bridges usually range from 100 to 200 m. The prestressing cables anchored in the deck beam run at a small angle and pass through a low pylon and then return to the slab in the beam on the other side of the pylon.

Low pylons allow to reduce the capital expenditure of the building by up to 30% in relation to suspended bridges. Additionally, this solution reduces the construction time and minimizes the technical problems associated with the construction of high pylons. Given their architectural attractiveness, extradosed structures are far superior to beam bridges. They look like suspended bridges, where the load-bearing structure may be considered as intermediate between the beam and the cable-stayed structure.

The approximate beginning of construction of such bridges dates back to 1988 when the French engineer Jacques Mathivat proposed a new type of prestressed concrete bridges. The originator of the extradosed bridges proved that they are a natural continuation of prestressed (beam) bridges, resulting from a better understanding of their structure. The current span is made using the cantilever bridge construction technology (with the use of a cantilever carriage).

The designer of the bridge is the company Sweco Polska Sp. z o.o.