A constitutive model formulation for predicting far-field deformation in peaty soft ground and its application to field embankment test

Abstract

A constitutive model extended from the modified Cam Clay model is proposed to predict more accurately the far-field deformation that occurs in peaty soft ground. The model considers the large initial stiffness developed at initial consolidation stresses and its degradation as function of shear deformation over a small to medium strain range. The initial stiffness values were sought by means of field sounding tests. A parameter controlling the elastic shear stiffness degradation can be determined through fitting the model to monotonic shear test results. This study also proposes its representative values that can be used as first estimates in practice. A simulation of a field embankment test with the proposed model demonstrated that the model can predict the far-field ground displacement in both the vertical and horizontal directions with better accuracy than the existing model.