New numerical technique for the inbuilt modified Cam clay constitutive model in Flac3D

Fast Lagrangian analysis of continua (Flac) is a powerful numerical platform for simulating the deformation and stability of geotechnical structures. However, it has been documented that the modified Cam clay (MCC) constitutive model embedded in the Flac platform is deficient at solving geotechnical problems. A new calibration approach by determining the isotropic pre-consolidation pressure (PCP) multiplier based on the relationship between the total stress in the geotechnical problem and the reference pressure is presented in this article. The multiplier was used to establish the nominated maximum isotropic PCP and the maximum referential consolidation ratio at the bottom of the soil layer. Subsequently, the maximum isotropic PCP was used to determine the bulk maximum. In addition, the developed approach was used to investigate the lateral displacement of a large grid wall foundation by deep mixing under adjacent surcharge loading. The feasibility of the approach was validated using centrifuge results. The coefficient of determination (R²) between the lateral displacement obtained from numerical and centrifuge modelling was 0.95. The proposed numerical technique and calibration approach demonstrated that the embedded MCC model can be used to solve practical geotechnical problems.