On the undrained analysis of soft anisotropic clays

Traditionally, a soil stability analysis of an undrained situation is either a Total Stress Analysis, using the undrained shear strength cu, or an Effective Stress Analysis, using \( \mathcal{c} ' \) and \( \phi ' \). Both approaches suffer from difficulties. The use of the undrained shear strength suffers from the drawback that its value depends heavily on the type of loading, as will also be shown in this paper. In engineering practice this difficulty is to some extent solved by using the cu-values from simple shear tests. The use of an Effective Stress Analysis suffers from the severe difficulty of estimating the excess pore pressures, being required as input data.