Numerical Experiments of Seabed Liquefaction during Ocean Wave Loading: Fid-Bau Portal

Numerical Experiments of Seabed Liquefaction during Ocean Wave Loading

Qiu, Yingqing / Mason, H. Benjamin

Seabed soil behavior under ocean wave loading is important to understand for the safety of coastal infrastructure, e.g., breakwaters, wind turbines, coastal armoring. A two-dimensional finite element model is generated in OpenSees to simulate nearshore seabed soil reaction to progressive wave loading by coupling pore water pressure and soil particle displacement. Wave loading is applied at the surface of a two-dimensional rectangular seabed domain as vertical pressure as well as pore water pressure. The numerical model is justified by comparing with analytical solution using different material parameters. A parametric study on model boundary effects shows that for the same wavelength wave, effective finite element domain size is not related to the full domain size as long as the lateral domain size is at least one wavelength. Soil liquefaction potential at different locations is studied with changing wave frequencies. A standing wave situation is also examined to simulate an ideally fully reflected wave in front of a coastal structure. The node and anti-node location of the standing wave greatly affect the liquefaction potential prediction. The results show that the wave properties are important for predicting soil liquefaction depth as well as liquefaction initiation time. Soil parameters like hydraulic conductivity and the elasto-plastic material behavior would also have the impact to the liquefaction region size and magnitude. This study provides a reasonable reference for further soil-fluid-structure interaction studies.