Flow-like landslides are very dangerous phenomena, involving both dry and saturated granular masses. To mitigate the associated risk, protection measures are generally built to intercept the propagating mass and stop/deviate it to avoid the impact with structures/infrastructures. The design of such protection measure is still mainly based on a pseudo-static design based on empirical formulas for the maximum impact force, bringing, in general, to a not rational design of the sheltering structure. In recent years, the development of continuum mechanics based numerical codes able to simulate large displacements problems has opened new frontiers on the study of the dynamic interaction between granular masses and obstacles by allowing their numerical simulation. Until now, the main limitations derive from the uncapability of such numerical codes to model phases interaction and separation, in case of saturated granular media, and the lack of the implementation of suitable constitutive laws for the solid phase able to take into account of material porosity and strain rate dependence. In this work, the impact of both dry and saturated granular masses against rigid obstacles is simulated by using the MPM code ANURA3D in which both simplified rheologies/elastic-plastic models and an advanced multiphase multiregime model [1] are implemented. In particular, the already implemented double point MPM formulation, considering two sets of separated material points for the solid and liquid phase respectively, has been considered to simulate phases separation. The obtained numerical results have allowed to discuss the differences between dry and saturated impacts and the fundamental role played by numerical and constitutive modelling choices to correctly simulate the dynamic interaction between flowing granular masses and obstacles.