The simulation of cone penetration tests (CPT) poses still a challenge to numerical modelling because large deformations and large displacements have to be considered. In this work the Particle Finite Element Method code G-PFEM, which employs an updated Lagrangian description, is utilized. The use of linear elements in combination with a stabilized mixed formulation and frequent remeshing of critical regions ensures computational efficiency. The well-known Clay and Sand Model (CASM), which is a model based on critical state soil mechanics principles, has been implemented in G-PFEM and extended to account for effects of bonding and destructuration. Cone penetration in a low permeable silt under undrained conditions has been simulated and the influence of the degree of bonding and the rate of debonding on calculated cone resistance is evaluated. In an additional study the influence of the shape of the yield surface, which can be controlled by two input parameters in the model, on cone resistance is investigated.