Vibration Characteristics of Kömürhan Highway Bridge Constructed with Balanced Cantilever Method

Kömürhan Highway Bridge is a reinforced concrete box girder bridge located on the 51st km of Elazığ-Malatya highway over Fırat River. Because of the fact that Kömürhan Bridge is the sole in this part of Fırat, it has a major logistical importance. So, in this paper it is aimed to determine dynamic characteristics such as natural frequencies, mode shapes and damping ratios of the bridge using experimental measurements to evaluate current behaviour. The experimental measurements are carried out by ambient vibration tests under traffic loads. Due to the expansion joint in the middle of the bridge, special measurement points are selected while experimental test setups constitute. Vibration data are gathered from both box girder and bridge deck. Measurement time, frequency span and effective mode number are determined by consider similar studies and literature. Peak Picking method in the frequency domain is used for the output-only modal identification. At the end of the study, dynamic characteristics of the Elazığ and Malatya part of bridge are compared with each other and torsional effects on the bridge are determined. Good agreement is found between dynamic characteristics in the all measurement test setups performed on box girder and bridge deck.