In the Polish part of the Jizera Mountains, directly on the slope of the High Jizera Ridge, the Queis River (Polish: Kwisa) rises at an altitude of about 940 meters. It runs through the Polish voivodships of Dolnośląskie (Lower Silesia) and Lubuskie (Lubuskie) and flows into the Bober after 127 kilometers. In the Polish town of Sagan, a military training area is located in the area of the Queis. Until now, military vehicles travelling in the area had crossed the river directly through the water. When the water level was high, however, the crossings were difficult. For this reason, a bridge was needed to enable military equipment to cross the Queis safely and at any time.
PORR and BBGS: Cross-border expertise from a single source
For the construction of the reinforced concrete bridge, an indirect foundation consisting of driven, altogether 38 prefabricated piles, each with a length of 10 m, was already in place in advance. The width of the abutments to be shored is 1 m with a height of over 6.50 m. In addition, the BBGS team installed seven prestressed concrete beams with a span of 25 m. The weight of each girder is 28.3 t. A crane with a lifting capacity of 300 t was used for the assembly. In addition, three turning areas with an area of 523 m2 are being built from fiber-reinforced concrete. The length of the constructed ballast access roads on both sides of the bridge will be approx. 400 m.
Challenges: Weather conditions and poor access roads
The team on site is working under difficult weather conditions, as much of the work is being carried out in winter. In addition, there was another task: during the first site visit, the team noticed the poor condition of the existing access roads. Solution: As part of the infrastructure preparation before the start of the project, community and forest roads were reinforced over a length of 800 meters. This allows the construction site to be reached safely even in bad weather conditions.
The project is expected to be completed in April 2022.