Abstract
Phan Thiet is a coastal city located in Vietnam. Recently, the coastal areas of the city have been suffering from severe coastal erosion due to a rapid coastal development such as land reclamations and port constructions. Without receiving a sufficient financial relief from the government, the local people have resorted to wood piles as a wave-breaking countermeasure to prevent coastal erosion. Particularly in developing countries, usage of low-cost countermeasures such as wood piles could be very beneficial. However, its effectiveness has yet to be scientifically proven. This study aims at confirming the effectiveness of a three-dimensional hydrodynamic analysis in evaluating the performance of wood piles. The present study performed a 3D numerical simulation, considering the offshore irregular waves and bathymetric conditions in Phan Thiet, Vietnam. The wave-energy dissipation and durability of wood piles were simply evaluated by two criteria: 1) wave run-up distance and 2) bending stress on pile. It is worth noted that remarkably large water levels could be generated because of multiple mechanisms such as the overlap of incident and reflected waves, stagnant water behind the piles, and intensified flow through the gap of the piles. These mechanisms cannot be adequately evaluated by a common 2D-numerical model with regular waves, demonstrating the benefit of the use of the 3D model.
