Technical triumph for one of the most significant stay cable bridges
One of the largest single pylon stay cable bridges in Europe spans the cove of the Ombla river north-west of the town of Dubrovnik. To allow for the very strong prevailing winds on the Croatian coast, the university of Aachen was engaged to perform preconstruction aerodynamic tests. The tests carried out in a wind tunnel in 1995 together with a computer simulation demonstrated the aerodynamic stability of the bridge concept.
The combined length of the bridge is 481.40 m consisting of 3 spans with lengths of 87.35 m, 304.05 m and 90.00 m. The deck, with a width between 12.70 m and 17.85 m, is designed for traffic on two lanes. The bridge consists of two inter-linked partial bridges: a 334 m long steel structure with a 143 m high λ-shaped pylon on the south side and a 147 m long prestressed concrete bridge with a 52 m high pier on the north side.
A total of 19 pairs of DYWIDAG Stay Cables with 27 to 61 Ø15.7 mm strands were used to carry the total load of the bridge deck. The two external stay fans are in line with the external steel girders and transfer the overall forces into the pylon head.
The post-tensioned bridge was constructed by the free-cantilever method using DYWIDAG Formtravellers and type 15 and 19 Ø15.3 mm DYWIDAG Bonded Post-Tensioning Tendons. The design was produced by the University of Zagreb, faculty for civil engineering and the project was commissioned by the Croatian Roads Authority.
Construction was successfully completed in April 2002 by a joint venture of Walter Bau, Germany, and Konstruktor, Croatia.
The bridge was opened 11 May, 2002.