Vidin – Calafat Bridge over the Danube. Romania-Bulgaria. 2012.
This bridge runs between Vidin (Bulgaria) and Calafat (Romania). The river is divided in two by the presence of an island. The part between Bulgaria and the island is not navigable and the part between the island and Romania is. The presented design provides an integrated solution for the crossing of the Danube for road and rail traffic on a precast concrete bridge in Vidin, Bulgaria. The central area within the bridge cross-section contains the railroad track, using both sides for car traffic. According to this solution, the bridge consists of three distinctly different structures: the main river crossing structure, the road approach spans and the railway approach spans. The main river crossing bridge is a continuous cable-stayed structure with five spans of 124, 180, 180, 180, 180 and 115 m in length. The central spans allow for the navigation channels of the Danube River. To improve the structural performance of the central spans, inclined struts have been provided. These elements allow the constant depth of the deck to be reduced, improving the structural performance of the cable retention system. In order to minimize the number of deck joints in the bridge, an integral design has been selected with a length of 1791 m between the expansion joints of the three piers. The deck cross-section consists of a prefabricated single box girder, with a depth of 4.50 m and a width of 31.35 m. The towers have deep foundations with a depth of 4.50 m and a width of 31.35 m. The towers have deep foundations with a width of 31.35 m. The towers have deep foundations made of perforated concrete piles. In order to provide protection against ship impacts, a new type of prestressed grillage has been designed to prevent direct ship impact against the towers along the approximately 11.0 m river level variation. The road approach span is a continuous prestressed concrete beam 612 m long, with seven 80 m spans and one 52 m lateral span. The rail section consists of a continuous prestressed concrete beam with a constant depth of 2.0 m and a length of 392 m, composed of 9 equal 40 m spans and a 32 m lateral span.


