CONSTITUTIVE MODELING AND ANALYSIS OF CREEPING SLOPES

A constitutive model for soils and interfaces involved in creeping natural slope is proposed. It is based on the hierarchical single-surface plasticity and viscoplasticity approaches and allows for factors such as elastic, plastic and creep strains, normal stress, and stress-path effects. The model is calibrated from a series of laboratory triaxial tests for soils obtained from the field site at Villarbeney Landslide, Switzerland, simple shear tests for interfaces, and simple shear creep tests for both. It is verified with respect to the laboratory tests used for finding the parameters and independent tests not used in finding the parameters. The model is implemented in a two-dimensional finite-element procedure, which is then used to back-predict observed field behavior at two locations at the Villarbeney Landslide. Typical comparisons between finite-element predictions and field data show that the proposed modeling procedure provides highly satisfactory correlations for the field situations considered herein.