Hanger replacement effect: experimental and numerical investigation on the Bosphorus Bridge

As from its construction, the Bosphorus Bridge underwent various retrofitting and repairment studies. The most critical one is the replacement of the inclined hanger ropes with vertical hanger ropes. The project is recently completed; however, the response of the bridge with vertical hanger is not estimated due to the lack of Structural Health Monitoring data. In this study, the effects of the vertical hanger arrangement on the bridge's response are aimed to be determined by making experimental data and numerical analyses. For this objective, finite element model of the bridge with inclined and vertical hangers are developed. Considering the modal analysis results, comparative study is conducted to identify the hanger replacement effects on the bridge. The outcomes reveal that the frequencies of the vertical deck modes of the bridge are changed as 10-25 \% in terms of frequency. Thus, stiffness ofthe bridge in vertical direction is obtained to increase