Modelling Behaviour of Cemented Clay Capturing Cementation Degradation

Abstract

This paper presents a constitutive model referred to as the Cemented Cam Clay (CCC) model to precisely simulate the cementation degradation of cement treated clays. Various laboratory experiments show that the effect of cementation gradually diminishes as the confining pressure increases, particularly at high effective confining pressures, due to breakdown of cementation bonds. The main concepts and the formulations of CCC model, including elasto-plastic stress strain relationships, are presented within the framework of the critical state concept and inspired by the Modified Cam Clay (MCC) model. The special characteristic of the proposed model includes a modified mean effective stress capturing cementation degradation. In addition, the failure envelope is formulated to describe the beneficial effect of cementation at low mean effective pressure range, while it merges with the Critical State Line of reconstituted cement-clay mixture as the confining pressure continues to increase. The performance of the proposed model is evaluated against triaxial test results from cement treated Aberdeen soil. The model predictions provide good agreement with triaxial test results, particularly at high effective confining pressures.