Numerical modelling of landslide behaviour

Landslides exhibit complicated and destructive behaviour with disastrous consequences. A landslide event is preceded by slope failure, which is governed by laws of soil mechanics. Once initiated, landslides often propagate downslope at rapid rates, exhibiting fluid-like behaviour. Landslide propagation is therefore frequently characterised by laws of fluid dynamics. Numerical models are vital for an improved understanding of these catastrophic events. Existing models are incapable of adequately simulating the dynamics of both initiation and propagation. Smoothed Particle Hydrodynamics (SPH) is a meshless method that is able to capture large displacements and rapid velocities, and it has been frequently applied to simulate landslide propagation. However, SPH is susceptible to numerical instabilities, that are particularly detrimental with regards to simulations of soil. These must be eliminated for SPH to be an ideal tool for general landslide modelling. The majority of approaches at removing the numerical instabilities from SPH are not universal -- some are applicable for small displacements problems only, while others require the tuning of artificial model parameters. In this research, a novel numerical model is developed capable of accurately simulating landslide behaviour -- including initiation and propagation. The numerical model -- Stress-Particle SPH -- removes instabilities in a way that does not require artificial parameter tuning. The method is an extension of SPH, and involves calculating velocities and stresses on two separate sets of particles -- nodes and stress-points. Previous literature suggests that the addition of stress-points have the potential to effectively stabilise SPH. Despite this, their implementation within SPH is relatively unexplored, and stress-points have only been applied to a limited range of problems. In this research, Stress-Particle SPH is extended for applicability to landslide behaviour, allowing the numerically stable simulation of high displacement problems with Stress-Particle SPH for the first time. The developments presented in this research offer the potential for SPH to tackle a broad range of problems beyond its current capabilities.