chapter  42
Numerical study of anisotropic permeability effects on undrained CPTu penetration
ByL. Hauser, H.F. Schweiger, L. Monforte, M. Arroyo
Pages 6

The numerical simulation of Cone Penetration Tests (CPT) is a challenging field in geotechnics. Both the underlying physical model and the numerical method need to be capable of taking into account large deformations and displacements within the problem domain. Researchers at the Polytechnic University of Catalonia (UPC) and the International Center for Numerical Methods in Engineering (CIMNE) have developed a Particle Finite Element Method (PFEM) code named G-PFEM which conducts fully coupled analysis of penetration problems in saturated porous media. An updated Lagrangian description is used in order to formulate the governing equations. The PFEM is based on frequent remeshing of critical regions of the problem domain adding additional computational cost to the solving process. Therefore, the use of linear elements in combination with a stabilized mixed formulation of the governing equations helps to reduce the computational effort and at the same time cope with the phenomenon of volumetric locking associated with linear elements. Within the present work, anisotropic permeability is introduced and tested by means of consolidation of an elastic soil layer. Furthermore, recalculations of an available in-situ CPT are performed allowing the examination of the influence of changing boundary conditions, such as anisotropic permeability of the soil or penetration velocity of the cone, on the measured tip resistance, sleeve friction and pore water pressure. It was found that the recalculation with G-PFEM provides comparable results for undrained conditions and anisotropic permeability.