Modelling of tsunami-induced bore and structure interaction

Abstract

A series of three-dimensional smoothed particle hydrodynamics (SPH) and finite-element (FE) models, with a domain in the form of a water tank, were undertaken to simulate tsunami-induced bore impact on a discrete onshore structure on a dry bed. The fluid motion was simulated using the SPH-based software DualSPHysics. The tsunami-like waves were represented by solitary waves with different characteristics generated by the numerical paddle wavemaker. Numerical probes were uniformly distributed on the structure’s vertical surface providing detailed measures of the pressure distribution across the structure. The peak impact locations on the structure’s surface were specifically determined and the associated peak pressures then compared with the prediction of existing commonly used design equations. Using the pressure–time histories from the SPH model, FE analysis was conducted with Abaqus to model the dynamic response of a representative timber structure. The results show that the equations used to estimate the associated pressure for design purposes can be highly non-conservative. By gaining a detailed insight into the impact pressures and structure response, engineers have the potential means to optimise the design of structures under tsunami impact loads and improve survivability.