Smoothed-Particle Hydrodynamics Numerical Modeling of Structures Impacted by Tsunami Bores

Abstract

Recently, major tsunami events have resulted in considerable damage to low-lying coastal developments as well as significant loss of life. This is owing to the fact that coastal communities and associated infrastructure are not able to withstand the extreme hydrodynamic forces induced by the overland progression of large tsunami waves. This paper reports the findings of a study, which is part of an ongoing comprehensive (hydraulic-structural engineering) research program initiated at the University of Ottawa in Canada. The goals of the latter are to contribute to the understanding and quantification of extreme hydrodynamic impacts on structural elements, and to the development of design guidelines for structures located in tsunami-prone areas. In this study, a single-phase three-dimensional (3D) weakly compressible smoothed-particle hydrodynamics (WCSPH) model is used to investigate the hydrodynamic forces, induced by the impact of rapidly advancing tsunami-like hydraulic bores, on a freestanding column of a square cross section. Numerical time histories of the water surface elevation and net base horizontal force acting on the column are compared with the results of large-scale physical experiments, conducted by the authors as part of an experimental component of this research program. The experiments were performed on the basis of analogies between tsunami bores and dam-break waves. The bore–structure interaction is analyzed in detail as the validated numerical model is subsequently applied to additionally investigate the influence of laboratory channel geometry on the results.