Volume-Change Characteristics of Normally Consolidated Clays

Abstract

The fundamental properties of volume-change of normally consolidated clays are discussed by theoretical considerations and experimental results.
The equation for the relationship between effective stresses and volumetric strain is derived by assuming superposition of strain due to isotropic compression and dilatancy.Both triaxial CU and CD Tests were carried out using Kaolin and CF Clay containing a less clay fraction than Kaolin.
The experimental results of Kaolin are shown to be in good agreement with the predicted values from the derived equation.As for CF Clay, the equation is of no use for the latter half of shearing. Since it was found from CU Test results that constants of CF Clay in the equation vary during shear, a modified equation is proposed.
Furthermore, a graphical method is presented for predicting volume changes from CU Test results. This method can be regardless of variations in the constants of the equation, and good agreement is found between the predicted and observed values for both clays.