Stability Analysis of Rubble Mound Breakwaters Under Tsunami Overflow

Abstract

Rubble mound (RM) breakwaters are the most commonly constructed breakwaters across the globe. Even though the breakwaters are designed to withstand to dynamic wave loadings, a natural disaster such as tsunami could impart additional loadings beyond the designed limits and thereby reduce the stability of the structure. Unfortunately, several RM breakwaters were severely damaged or even collapsed under the impact of past tsunamis such as the 2004 Indian Ocean tsunami and 2011 Great East Japan tsunami. The failure of these breakwaters would lead to the inundation of tsunami waves to the coastal areas causing devastating damages to life and property. Therefore, it is relevant to make the RM breakwaters resilient against tsunami impacts, so that the breakwater can either completely prevent or at least reduce the impact height of tsunami waves. In order to design a RM breakwater resilient against tsunami, the failure mechanisms under tsunami overflow conditions have to be properly understood. The present study thus aims to numerically evaluate the stability of RM breakwaters under tsunami overflow conditions. The cross-section details of the North breakwater at the Ennore Port, Chennai, India have been modelled at full scale in the finite element software Plaxis. The model was then subjected to a tsunami overflow condition. The corresponding deformations and stability of the RM breakwater were estimated. It was observed that the stability of the breakwater was considerably reduced under tsunami overflow conditions. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.