ASSESSMENT OF THE DR. FRANJO TUĐMAN BRIDGE ON THE STATE ROAD D8 IN DUBROVNIK

On the bridge of Dr. Franjo Tuđman over Rijeka Dubrovačka, a visual inspection and measurements of the dynamic characteristics of the span assembly and tension were performed. The survey was conducted in May 2020 by project partners from the Faculty of Civil Engineering and the Faculty of Electrical Engineering and Computing.

Dynamic testing of the span assembly was performed at 112 points in two mutually perpendicular directions – longitudinally and perpendicular to the direction of the bridge extension. Based on the performed measurements, the basic dynamic parameters were determined – natural frequencies, forms of oscillations and damping coefficients. Dynamic tensile tests (38 in total) determined their own frequencies and damping coefficients. From the obtained values ​​of the natural frequencies, an estimate of the value of the force in them is given. These results are extremely important for the development and calibration of a numerical model of the bridge and comparison with the results of previous measurements.

Visual inspection of the bridge includes elements of the pavement structure, abutments, staircase, pylon and prestressed concrete box. Inspection of inaccessible parts of the span structure and bridge elements was performed by unmanned aerial vehicles (drones). As part of the inspection, the condition of the concrete was checked with a sclerometer and the thickness of the layer of anticorrosive protection on the steel elements.