Numerical Modeling of Wave-Induced Seabed Liquefaction: A Drift-Flux Model for Liquefied Soil

Seabed liquefaction, a phenomenon induced by dynamic loading, poses a significant risk to the structural integrity of marine installations such as pipelines, breakwaters, and offshore platforms. Accurate numerical modeling of this complex process is essential for ensuring the safety and longevity of such structures. This study introduces an advanced OpenFOAM (foam-extend 4.1)-based numerical model that - for the first time - holistically simulates seabed liquefaction and compaction processes. Building upon Biot's poroelasticity theory for nonliquefied regions and the drift-flux model for liquefied regions, the new model offers a comprehensive hydro-geotechnical representation of seabed response to wave-induced loading, covering the full spectrum of the liquefaction process in a unified framework. Through validation against experimental data, the model demonstrates high accuracy in capturing the intricate dynamics of seabed soil subjected to varying wave periods and heights. In addition to its successful simulation of the onset of residual liquefaction, the model excels in addressing the accumulation of pore pressure and soil behavior after liquefaction takes place. The numerical model results consistently achieve a R 2 score greater than 0.9 compared to experimental pore pressure measurements, indicating its high accuracy in predicting seabed responses. The model's performance signifies its potential as a valuable tool for the coastal and offshore engineering community. This research provides a robust toolset for the research on and an understanding of seabed liquefaction and its implications for marine structures.