engleski

Dubrovnik bridge - design, construction and service performance

The only cable stayed bridge in Croatia, the Dubrovnik bridge, was opened for traffic in the year 2002. The cable stayed main bridge with composite superstructure is jointed in span to the prestressed concrete approach bridge by a hinge type hinge connection. The main and detailed designs were carried out by the team from the Structural Department of Civil Engineering Faculty in Zagreb, based on preliminary design by Prof. Schambeck and Sporschill [1] . Essentials of the Dubrovnik bridge design and construction are presented in the paper. The bridge has experienced vibrations of stay cables under certain wind conditions, as with many other cable-stayed bridges around the world. After a short review of results of wind tunnel tests and various numerical analyses, field observations of rain-wind induced stay cable vibrations are highlighted. Only after extremely violent movements of stay cables and the superstructure under heavy damp snow storm occured, resulting in substantial damage, was it decided to apply vibration mitigation measures. Adjustable cable dampers, based on MR technology were installed on the bridge to raise low structural damping of mostly affected stay cables. Theoretical computations suggest that the stay cable vibrations shall be strongly reduced. Accelerometers and displacement transducers shall be placed on some stay cables to continuously monitor their motion.

Cable stayed bridge; Prestressed concrete; Vibrations; Dampers

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