Soil Mechanics Constitutive Modelling for Soft Cohesive Soils

Constitutive models developed in 1960s and 1970s by a group in Kyoto, with Shibata as the central figure, happen to have a theoretical framework mathematically similar to that of the Cam Clay models developed by the Cambridge Soil Mechanics Group in 1960s. The models developed in Kyoto were based on volume changes measured during constant stress ratio consolidation (q/p'-constant drained shear), and negative dilatancy (or contractancy) measured during p'-constant drained shear. The Cam Clay models were developed from assumptions of energy dissipation during shear. This chapter presents an interpretation of the physical meaning of dissipated energy and reveals the mathematical similarity between these two groups of constitutive models.