Abstract
An evaluation of slope stability using the finite element method is often performed as a complementary analysis to the plastic deformation analysis. The slope stability is typically evaluated by the reduction of the strength parameters c and phi of the Mohr-Coulomb model and it is represented by the so-called factor of safety.
It is much less common to use the strength reduction method in combination with more advanced constitutive models and, for some modelling frameworks, it has actually not yet been developed. This leads to the need for advanced model substittion by the Mohr-Coulomb model and a further recalibration of the constitutive model parameters.
In this paper, a new strength reduction method was developed for the models based on hypoplasticity, in particular to the hypoplastic model for clays. In addition to a simple reduction of the strength variables, a subsequent return of the deviatoric stress to the asymptotic state boundary surface is implemented so that all the integration points remain within the so-called asymptotic state boundary surface.
Predictions using the newly developed method are thoroughly tested from the quantitative as well as qualitative point of view and compared with the predictions obtained from the Mohr-Coulomb model.