This paper presents a new design numerical tool for geosynthetic-reinforced soil embankments, used to mitigate rockfall risk in scenarios of large volumes, energies, and multiple block failures. The model can simulate both local block penetration into the uphill embankment face and extrusion mechanism frequently affecting the downhill face. The new model is based on an existing elastic-visco-plastic model, originally developed to simulate impacts of blocks on homogeneous granular strata. The model has been enhanced and modified by incorporating a plastic mechanism, accounting for the extrusion process potentially occurring within the embankment body. The model is initially described and then validated using available in situ real-scale test data; finally, the results of a parametric study, examining the influence of the main controlling parameters and the applicability of the tool for pre-design purposes, are illustrated.

Granular materials - aggregates of many discrete, disconnected solid particles - are ubiquitous in natural and industrial settings. Predictive models for their behavior have wide ranging applications, e.g. in defense, mining, construction, pharmaceuticals, and the exploration of planetary surfaces. In many of these applications, granular materials mix and interact with liquids and gases, changing their effective behavior in non -intuitive ways. Although such materials have been studied for more than a century, a unified description of their behaviors remains elusive. In this work, we develop a model for granular materials and mixtures that is usable under particularly challenging conditions: high -velocity impact events. This model combines descriptions for the many deformation mechanisms that are activated during impact - particle fracture and breakage; pore collapse and dilation; shock loading; and pore fluid coupling - within a thermo-mechanical framework based on poromechanics and mixture theory. This approach allows for simultaneous modeling of the granular material and the pore fluid, and includes both their independent motions and their complex interactions. A general form of the model is presented alongside its specific application to two types of sands that have been studied in the literature. The model predictions are shown to closely match experimental observation of these materials through several GPa stresses, and simulations are shown to capture the different dynamic responses of dry and fully -saturated sand to projectile impacts at 1.3 km/s.