STRUCTURE AND INFRASTRUCTURE ENGINEERING, cilt.19, sa.6, ss.1-35, 2025 (SCI-Expanded, Scopus)
Scour defined as the water-induced erosion of soil around the bridge piers poses a significant threat to the stability and safety of bridge. Investigation of scour effects around the piers of the bridge is essential to ensure the long-term performance of bridges. This study examines the effects of local scour on the structural integrity of highway bridges by integrating on-site measurements, 3D computational fluid dynamics (CFD) simulations, and nonlinear finite element (FE) analysis. A highway bridge located over the Senoz Stream in Çayeli, Rize (Türkiye), which suffered significant pier damage due to time-induced local scour, is considered. Since site investigation on the damaged bridge was not feasible, a nearby structurally identical bridge was selected for testing and simulation. Ambient vibration tests were conducted to identify the dynamic properties of the intact bridge, an initial FE model was created updated based on modal testing and static loading results. The local scour depth around bridge piers was estimated for different scenarios using validated 3D CFD simulations based on a synthetic flow input derived from different return periods (Q10, Q50, Q100, Q200, Q500, Q1000), calculated using the Gumbel distribution. The scour depth was then incorporated into a nonlinear FE model using a Concrete Damage Plasticity (CDP) approach to simulate failure mechanisms. The numerically obtained damage patterns were found to closely match the actual collapse observed in the damaged bridge. The novelty of this study lies in the integrated use of field-based modal testing, advanced CFD scour modeling, and nonlinear damage assessment to realistically simulate scour induced bridge failure. The results emphasize the importance of coupling hydraulic and structural analyses to improve bridge safety assessments under complex environmental hazards