Modeling of solitary wave-induced scour around structures: SPH-based analysis and experimental validation

This paper investigates solitary wave-induced scour around square structures, a critical factor affecting the integrity of coastal infrastructure. The phenomenon is studied numerically and validated through original experiments conducted in our laboratories. Specifically, a solitary wave interacting with a square structure on a beach with bathymetry representative of Chilean coasts is analyzed. Additional validation is performed using an experiment from the literature involving dam-break-induced scour behind coastal dikes. The numerical modeling is carried out using DualSPHysics, an open-source simulation tool based on the Smoothed Particle Hydrodynamics (SPH) method, which has shown effective results for wave modeling and scour studies. This study demonstrates the model’s effectiveness in addressing wave-induced scour problems. The interaction between a tsunami-representative solitary wave and the sediment is modeled using the Herschel-Bulkley-Papanastasiou (HBP) model for granular materials. The results show that the numerical model, combined with the rheological model, accurately predicts the maximum scour depths in both configurations. Furthermore, the simulations closely align with experimental observations and previous studies, confirming that scour depth correlates with flow depth, with deeper scour occurring at the corners of structures compared to the central faces. These findings improve predictive capabilities for tsunami impacts on coastal structures, highlighting the need for future research to incorporate more realistic wave characteristics to enhance prediction accuracy.