The impact of tsunami-induced bores on buildings

Abstract

The impact of tsunami-induced bores on buildings was investigated experimentally using 1:100 scale models. Three nominal wave conditions roughly equivalent to the maximum flow depths found at the modelled locations were investigated. A solitary-like wave was generated in deep water by the abrupt release of water from an elevated tank of known storage volume. This type of crest-led wave typically breaks on mildly sloping beaches and here became a bore-like broken wave before reaching the model. Based on the pressure profile at various instants in time, a simplified pressure profile is proposed for the maximum force acting on the structure during the run-up process. The force per unit width for a rectangular building is approximately the same as that experienced by a square configuration. The force on the projected area of an octagonal building, however, is reduced by about 20% compared with the square building. The reduction in wave force on the front panel is estimated to be about 25 and 50% for an opening configuration of 25 and 50%, respectively.