Impact of Flood Loading on a Representative Steel Girder Bridge

To enhance the economic growth of a nation, efficient and affordable mobility of people and transportation of goods are essential. In this regard, highway bridges—one of the key components of highway transportation networks—play a pivotal role. Generally, bridges are designed to survive against design loading during the life span. However, unpredictable natural disasters such as extreme floods may endanger the safety and serviceability of bridges during their design life and produce a tremendous economic loss to the society they serve. This very important matter is currently being investigated by the structural engineering community, and more studies are required to develop a comprehensive knowledge base on the topic. In this relation, the study here considers a representative steel girder bridge and analyzes its response under possible flood scenarios. Several bridge design provisions for floods are reviewed, and representative cases of flood load on the bridge are formulated. Numerical simulations for different flood-induced loading cases with various combinations of flood velocity and water height reveal that the flood vulnerability of the bridge increases with velocity and water level. The debris loading increases by 1.5 times its hydraulic pressure when they act concurrently. However, after a certain level of flood height, the hydraulic pressure does not change, whereas the debris pressure continues to increase with increasing water height. The outcome of this research provides a better insight into the problem and identifies key areas for future research to improve the failure probability of bridges under extreme floods.