Author(s): Harish Selvam; Holger Schuttrumpf

Linked Author(s): Harish Selvam

Keywords: Tsunamis; Vertical seawalls; Flow overtopping; Numerical simulation; Overtopping forces

Abstract: The field surveys after the past tsunami events demonstrated that despite the tsunami waves overtopping the seawalls at many coastal regions, the forces on the inland structures reduced due to the presence of seawalls. The past events also demonstrated that the seawalls experienced significant damage due to highly energetic tsunami wave interaction for a longer time. Thus, strengthening or designing the seawalls to the expected tsunami load can reduce the damage to the seawall and can increase the efficiency in reducing overtopping tsunami energy. Hence, the present study is motivated towards understanding the overtopping flow and the force characteristics on the vertical seawall during tsunami-like flow interaction. An open-source CFD solver called OpenFOAM is used for numerical simulations. During the flow interaction, the seawalls experienced impulsive force during bore-front interaction, followed by quasi-static force during the quasi-steady flow phase. The low-rise seawall experienced maximum force during the initial impulsive force phase, while the high-rise seawall experienced maximum force during the quasi-steady flow phase. The bore depth at the seawall’s front (hf) is found to reduce with the decrease in the seawall’s height. The forces on the seawall was found to decrease with the decrease in height due to the compensating backward pressure due to flow overtopping. The present study improves the understanding of tsunami interaction with the seawall under overtopping conditions.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1997-cd

Year: 2025