Investigation of flood effects on bridges

When the disasters occurred in our country and the world are examined, earthquakes in the first place and floods come in second place. The reasons causing floods to increase the risk of people's lives by increasing today; climate changes, unplanned urbanization, playing with stream beds or covering the river, etc. can be listed as. The most important structures that can be damaged during flooding are the transportation bridges built for the passage of people on the river. A bridge that is not well designed according to the basin and climate characteristics of the region and has a low foot opening accumulates material during flooding and sets the way to the incoming water. Consequently, it is damaged or destroyed by failing to resist the large hydraulic water force coming in. This further exalates the devastating impact of flooding in the region and endangers the safety of people's lives and property. For this reason, it is very important that the bridges overcome the negativities during the flood with the least damage. Since the infrastructure elements of the river bridges are within the active river flow area, they are exposed to more negative external factors compared to other water structures. For this reason, the condition of the current river bridges should be monitored regularly and precautions should be taken to avoid hydraulic and static problems in case of a disaster. In this study, with the HEC-RAS package program of the Nursery bridge on Porsuk stream, flood risk analyzes were performed, and the reliability of the existing bridge at the moment of flooding was investigated and solution suggestions related to bridge reliability were presented. As a result of the analysis, Arc-GIS and HEC-GeoRAS were determined in accordance with the terrain topography, river flow characteristics and bridge geometry in the computer environment, where the river nursery bridge can safely meet the Q50 and Q100 annual flood flows, and it was tested in accordance with the HEC-RAS program. Thus, the security analysis of existing river bridges and new bridges will be made in advance with the HEC-RAS program and precautions to be taken for bridge security can be determined by foreseeing. Thus, river bridge security will be provided, and life and property security of people can be provided with bridge analyzes to be carried out beforehand.