Towards Submarine Landslides and Their Consequences

ended

The last decade has witnessed a boom in offshore infrastructures, including not only oil and gas platforms and submarine pipelines due to the shift of energy exploration from onshore to offshore but also offshore wind farms, offshore electricity grid infrastructure, and submarine communication cables and routes. This boom significantly enhances the importance of the estimation of potential submarine landslides and their consequences. It is true that submarine landslides may have a unexpectedly long travel distance and damage infrastructure thousands of kilometers away. However numerical modelling of the entire process of submarine landslides is a long-standing challenge. In addition to constitutive models for describing both solid-like and fluid-like behaviour of sediments, it requires also advanced numerical approaches capable of tackling extremely large deformation experienced by materials as well as interactions between structures, seawater, and sediments. This project is motivated by these challenges and aims to develop innovative continuum models and numerical approaches for simulating submarine landslides and their consequences. A unified mixed Lagrangian finite element formulation will be derived for handling solid mechanics (infrastructure), fluid dynamics (seawater), and poromechanics (sediments). Viscoeplastoplastic constitutive models will be developed for capturing the solid-fluid transitional behaviour of sediments. The proposed formulation and models will be implemented on a high performance computing based numerical platform within the framework of the particle finite element method for fully coupled analyses of submarine landslides. The intended outcome is a computational tool that can simulate the complete process of real-world submarine landslides, ranging from the initiation of failure through the sliding process to the final deposition and predicting their impact on offshore infrastructures.