Performance of a reinforced embankment on a sensitive Champlain clay deposit

An existing elastoviscoplastic constitutive model is modified using concepts of the state-dependent fluidity parameters and the damage law, to incorporate the effect of soil structure and its destructuration. The model is employed to simulate the performance of a well-documented case study of the reinforced test embankment constructed over a sensitive Champlain clay deposit at Saint Alban, Quebec. The finite element calculations, using both the original (nonstructured) and modified (structured) elastoviscoplastic soil models, are compared with the observed field data from a test embankment brought to failure. The results from the structured elastoviscoplastic soil model show better agreements with the field data when compared with those analyzed using the nonstructured elastoviscoplastic soil model. The modified model captures many features of the reinforced embankment behaviour, such as vertical settlement, excess pore-water pressure responses, and reinforcement force. However, they also reveal the fact that another important characteristic of the natural clay deposit — anisotropy — needs to be considered to provide an adequate prediction of horizontal deformations. The role of geosynthetic reinforcement and its viscosity on short-term responses of the reinforced embankment examined in this study is also discussed