Abstract
A series of triaxial tests was performed on undisturbed samples of soft Bangkok clay, which were consolidated under different constant stress ratios, to study the pore pressure development under monotonic loading conditions. The test results are interpreted through a pore pressure : stress ratio relationship. The behaviour of isotropically consolidated samples in the normally consolidated state shows a linear relationship between the pore pressure and the stress ratio under monotonic loading conditions and the same patterns were also established for other clays such as kaolin, Drammen clay and Boston Blue clay. Overconsolidated samples, and anisotropically consolidated samples showed bi-linear variation on the same plot. The linear/bilinear variation in the pore pressure-stress ratio relationship was used to develop simple expressions for the undrained stress paths for different initial conditions of the samples, using simple soil constants.
