Adaptive two-phase Particle Finite Element model for soft soil excavations in partially saturated soils

Abstract

A coupled solid velocity-water pressure (vp) Particle Finite Element (PFEM) formulation in conjunction with a hypoplastic model for sandy soils is presented. Large deformations of the soil and the ever-evolving topology of the ground free surface, key features characterizing the cutting tool-soil interaction, are efficiently captured via the PFEM. The utilization of a hypoplastic constitutive formulation allows for the realistic modeling of the non-linear behavior of the soil deformable skeleton. The hydromechanical description of the partially saturated soft soil is completed by incorporating the van Genuchten hydraulic model for the calculation of the Soil Water Retention Curve (SWRC) in combination with the Karman-Cozeni equation for the estimation of the soil permeability. Finally, computational simulations of tool-soil interaction performed in sand are compared against experiments and the capabilities of the proposed model are demonstrated.

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