Analysis of mechanical characteristics of soft soil under different stress paths

Based on a series of consolidated-undrained stress path tests, the mechanical characteristics of soft soil from Guangzhou Nansha under different consolidation conditions are systematically studied. The effect of initial consolidation on stress paths dependence of soft clay is analyzed; the characteristics of stress-axial strain relation and pore water pressure distribution under different stress paths are compared; and the connection of pore pressure and soil deformation state is discussed; the lateral unloading will induce shear dilatation of clay soil because of shearing stress increased and volume stress decreased. The test results also show that the effective stress paths under consolidated undrained shear is main related to initial consolidation; as a result the effective stress paths is only one under the same consolidated state. In addition, shear controlled mode of test has evident effect on the effective stress paths, but little influence on soil shear resistance.