ABSTRACT
The environmental and climatic conditions are generally reviewed in the early phase of layout plan determination for bridges crossing over streams. In this review, flood flow rate of the stream is obtained and bridge’s spanning, vertical clearance and type of piers are determined. If there are piers, they are placed in the stream, piers are exposed to negative effects of water during their service life. The most important problems that occur around the bridge piers are depositions and scouring. Due to these cyclic effects bridge structures may experience stability problems and collapse. In order to decrease these negative effects, stream characteristics around the piers should be investigated and the required data, such as flood flow rate and flow velocity, obtained. These data can be used in determination of stabilities of bridge piers. In this study, twelve bridges located in Ordu, Turkey are investigated which were damaged and collapsed due to the flood that occurred in July 2018. The investigation covers the hydraulic effects which cause the bridges to collapse. Also, the design principles of the new twelve bridges and field precautions to prevent depositions and scouring of piers are studied.
