Compression Strength of Soils

In this chapter, the probabilistic porous-solid model is used to determine the mean effective stress of soils at failure. The plot of the deviator stress against the mean effective stress shows a unique failure line for a series of triaxial tests performed at different combinations of the confining net stress and suction for both wetting and drying paths. This result confirms that the proposed effective stress equation is adequate to predict the shear strength of unsaturated soils. It also results in different strengths for wetting and drying paths as the experimental evidence indicates.

Keywords: Shear strength, effective stress, net stress, triaxial tests, confining stress, axis translation technique, constant volume test, friction angle, wetting path, drying path, porous-solid model, soil-water retention curve, logarithmic normal distribution, critical state, pore size distribution, grain size distribution.