Wave-induced liquefaction around the head of a breakwater
Protection of the coastal environment is vital for countries like Australia, where 86% of the total population is concentrated around coastal regions. Marine structures such as offshore breakwaters are commonly adopted for such protection. Design of marine structures considering their stability is a rather complicated problem. One of important factors which have to be taken into considerations in the design procedure is the wave-induced seabed instability (liquefaction) in the vicinity of the structures. It has been well documented that ocean waves propagating over the ocean surface exert dynamic pressure fluctuations on the sea floor. These fluctuations further generate an excess pore pressure within the soil skeleton, which have been recognized as a dominant factor in analyzing the seabed instability. Recently, some marine structures (for example, Sine Breakwater in Portugal) have been reported to be damaged by seabed instability at their toes. Furthermore, it has been observed that a deep hole exists near the tip of a marine structure. Without proper maintenance at these sites, failure of structures may be expected.
The major objective of this project is to investigate the wave-induced seabed response at the tip of a breakwater. An analytical solution and finite element model will be established to implement the theory. The specific goals of this project are to:
* Derive a mathematical solution for the wave-seabed interaction at the tip of a breakwater with a horizontal seabed with combination of two mechanisms of soil response.
* Develop a numerical model for the more realistic case with non-uniform seabed.
This project is support by USYD Research & Development Grant (2005)