Figure 1. Yield surface in (q-p'-s) stress space
In this paper, unsaturated soil behaviour is numerically simulated using a modified version of the Barcelona Basic Model. The model has been implemented as a User-Defined Soil Model (UDSM) in the finite element code PLAXIS. Unlike the original formulation based on net stress, this model is formulated based on the well-known Bishop's effective stress, with suction as an additional stress variable. Furthermore, a non-associated flow rule and the dependency on Lode's angle are incorporated. The Soil Water Characteristic Curve (SWCC) follows the Van Genuchten model. First, the simulation of laboratory tests along different stress paths and levels of suction are compared against experimental data. Then, an unsaturated soil embankment subject to a time-dependent precipitation is simulated by means of a fully coupled flow-deformation analysis. The results show the capability of the model to reproduce the main features of unsaturated soil behaviour both at material point level and in boundary value problems.
This paper was presented at the 8th International Conference on Unsaturated Soils (UNSAT 2023), and is available here:Finite element modelling of unsaturated soils using a modified version of the Barcelona Basic Model - Laera, et al. (2023); https://doi.org/10.1051/e3sconf/202338215005.
Citation Finite element modelling of unsaturated soils using a modified version of the Barcelona Basic Model Anita Laera, Tuan Anh Bui, Sandro Brasile E3S Web of Conf. 382 15005 (2023) DOI: https://doi.org/10.1051/e3sconf/202338215005
PLAXIS Barcelone Basic model (UDSM) [Models]
Coffee Corner: Modelling unsaturated soil behaviour with PLAXIS Barcelona Basic model (April 2023) [Webinar]
Groundwater flow, fully coupled flow deformation and undrained analyses in PLAXIS 2D and 3D [Publications]