A Large Deformation Finite Element Formulation for Subgrade Soil Compaction

Abstract

Subgrade soil compaction can generate a volumetric locking phenomena if standard displacement-based finite element formulation is used to model the their nearly incompressible limit. This is a potentially problematic issue for pavement compaction for either asphalt or subgrade soil. This paper presents a stabilized large deformation finite element formulation for compaction simulation. The stabilization technique employed here for the mixed displacement-pressure formulation is based on the variational multiscale idea. It is written in the spatial description and is integrated with a smooth surface Cap model for the analysis of materials that can take large compressive stresses but very low tensile stresses. Numerical experiments using hexahedral elements with equal low-order interpolations for both displacement and pressure fields show that the new stabilized formulation can successfully remove volumetric locking. This formulation effectively predicts the compaction density induced by the external loads, which is an attractive feature of the formulation for practical applications in geotechnical/pavement engineering.