A comparative study of shear strength equations for unsaturated soils

Shear strength is the one of the most fundamental issues in the study of unsaturated soils. Different strength equations have been proposed for predicting shear strength of unsaturated soils. Some of these equations are based on regression of experimental data, while some of them are embodied in more complex stress-strain constitutive models. In this paper, a number of shear strength equations for unsaturated soils are examined and compared with experimental data. Data for both air-dried and compacted specimens are used in the comparison. The advantages and limitations associated with different equations are discussed.