Tropical Clays. II: Engineering Behavior

Abstract

The general impression with tropical soils showing changes in plasticity characteristics upon drying is that the compressibility decreases, and shear strength and permeability increase with drying. The study reported in this paper within the frame work of generalized state parameter approach shows that these observations, in a general sense, need be treated with caution. Drying causes a reduction in the overall potential represented by liquid limit leading to a reduction in void ratio for equilibrium under a given load such that the same pore structure exists when equilibrium condition is reached. This means the permeability coefficients do not increase with drying under a given load but considerable settlement occurs. Further, due to the reduction in void ratio, under a given external loading, being commensurate with the reduction in liquid limit due to drying, shear strength also does not increase with drying.