Axisymmetric Simulations of Cone Penetration in Saturated Clay

Abstract

A direct axisymmetric cone-penetration model developed for use with a user-written implementation of the MIT-S1 constitutive model is presented. The penetration model uses a finite-difference program with an Arbitrary Lagrangian Eulerian algorithm that couples the program’s large-deformation Lagrangian formulation with user-written algorithms for rezoning and second-order Eulerian advection remapping. Numerical examples illustrate the performance of the remapping and advection algorithms and cone-penetration simulations. Cone penetration at a Boston blue clay site is simulated with the Mohr-Coulomb, modified Cam clay, and MIT-S1 constitutive models and compared with measured cone-penetration test profiles. Single-element simulations illustrate that the MIT-S1 constitutive model captures the significant undrained shear-strength anisotropy exhibited by Boston blue clay, whereas the modified Cam clay and Mohr-Coulomb models do not. Penetration simulations demonstrate the important effect of undrained shear-strength anisotropy on the cone tip resistance, as well as on stress and pore pressure fields around the cone tip and rod.