This paper investigates the implementation of a nonlocal regularisation of the material point method to mitigate mesh-dependency issues for the simulation of large deformation problems in brittle soils. The adopted constitutive description corresponds to a simple elastoplastic model with nonlinear strain softening. A number of benchmark simulations, assuming static and dynamic conditions, were performed to show the importance of regularisation, as well as to assess the performance and robustness of the implemented nonlocal approach. The relevance of addressing stress oscillation issues, due to material points crossing element boundaries, is also demonstrated. The obtained results provide relevant insights into brittle materials undergoing large deformations within the MPM framework.

Chalk is present in a large area of the East and South coast of the UK where renewables are now being installed. In most cases they are founded on displacement piles, whose design uses empirical methods or partial (wished-in-place) simulations. Installation effects such as grain crushing and pore pressure generation are conservatively estimated (if considered at all), as the change of chalk properties around the pile due to pile installation cannot be easily quantified. In this work it is shown how advanced numerical modelling can be used to guide the design of the foundations in these complex soils.