Author(s): Natasha Petruccelli; Diego Panici; Alessio Domeneghetti And Armando Brath
Linked Author(s): Diego Panici, Alessio Domeneghetti
Keywords: Flood risk bridges hydrodynamic forces CFD modelling Flow 3D-Hydro
Abstract: The occurrence of intense rainfall events, combined with the aging state of existing structures and the increase in traffic loads, has nowadays contributed to the growing vulnerability of bridges to flood risk. In particular, the overtopping of the bridge deck during flood events can induce additional hydrodynamic forces on the structure, which may lead to sliding and/or overturning of the bridge. In addition, in the case of debris accumulation around bridge piers, such as Large Woody Debris (LWD) transported by the current, the acting forces can be significantly amplified, further reducing the structural load-bearing capacity. This work examines the behaviour of a beam-type scheme under different hydraulic conditions with the intent of developing an application tool capable of providing designers with a preliminary assessment of the expected hydrodynamic loads on bridges in the case of overtopping. By using CFD modelling, the three-dimensional flow field around the bridge is investigated for various turbulence models (RNG, k-ω). Drag and lift forces, as well as the overturning moment acting on a rectangular deck are estimated as a function of the submergence level and the Froude number. The developed CFD code is calibrated using existing experimental measurements in the presence of LWD around piers (having different geometries: circular, ogival and semi-circular) and validated with actions recorded in the laboratory in the absence of accumulations for a rectangular deck. Results are presented in terms of synthetic curves of the dimensionless force coefficients (drag, lift and momentum), which may support bridge safety assessment and design.
Year: 2025