The only cable-stayed bridge in Croatia, the Dubrovnik bridge, was opened for traffic in 2002. The main cable-stayed bridge with composite superstructure is jointed in span to the prestressed concrete approach bridge by a hinge-type connection. The bridge has experienced vibrations of cable stays 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 cable-stay vibrations are highlighted. Only after extremely violent movements of cable stays and the superstructure under a heavy, damp snowstorm occurred, resulting in substantial damage, was it decided to apply vibration mitigation measures. Adjustable cable dampers, based on the latest MagnetoRheological (MR) technology, were installed on the bridge to raise low structural damping of the most affected cable stays.

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<p>Research on development of seismic assessment procedure for existing bridges will be presented in this paper. Both the linear response spectrum analysis and the nonlinear static pushover method are used and results were evaluated following the demands defined by current European seismic design codes. At first, this procedure is validated by its application to major Adriatic arch bridges with spans ranging from 200 m to almost 400 m as a part of an extensive project to develop their appropriate maintenance strategy. Seismic assessment is further developed and their suitability is proved at different bridge types.</p>

All civil engineering structures are deteriorating in time, at a different rate. The current and future states of a structure are associated with various degrees of uncertainty, and, therefore, a probabilistic approach is appropriate in order to predict future needs for maintenance and repair. Some existing models use discrete-time Markov processes called Markov chains. In this paper, homogeneous Markov processes (HMPs) with a finite set of condition states and a continuous parameter (time) are used. The aim is to make a probabilistic forecast of the condition of the structure, using time as a continuous parameter, so that probabilities of condition states can be calculated at each moment. The model is applied to the calculation of probability of possible future deterioration of the piers of Krk bridge (Croatia) that have already been repaired.