Applicability of Cam-Clay Models for Tropical Residual Soils

Abstract

The development of a critical state framework for saturated soils provides a powerful conceptual model based on the generalized principles of the elasto-plastic behavior of frictional materials (Schofield and Wroth, Critical state soil mechanics, 1968]. The model has been modified to meet the requirements of more complex applications (Wheeler, Proceedings of XIV ICSMFE, 1997). An attempt has been made in the present paper to apply conventional Cam-clay models to capture the stress–strain–pore pressure response of tropical residual soils. For this purpose oedometer tests and consolidated undrained triaxial tests were conducted on undisturbed soil specimens and reconstituted soil specimens of five soils collected form the surrounding areas of Tirupati in Andhra Pradesh. Using the Cam-clay models the predictive capabilities of these models are brought out in comparison to the experimental results on tropical residual soils. It has been shown that the Cam-clay models can only capture the behavior of remolded soils devoid of cementation whereas the Wheeler model can effectively predict the behavior of natural soils considered in the present investigation which show strain softening associated with positive pore pressures.