Soft Soil Behavior Under High-Speed Railway Embankment Loading Using Numerical Modelling

Artesian aquifers underlying soft lacustrine deposits impacts the rate of consolidation and modify their inherent characteristics. In Drader area Morocco, a detailed subsoil investigation is primarily conducted under the Moroccan high-speed railway embankment, to localize the shallow artesian aquifers and to clearly define the structural component contributing to the existence of this deposition mechanism. Based on the field measurement during the embankment construction phase, it become clear that the large deformation was affected by slower increase in effective stress than expected. For that, two-dimensional (2D) full embankment over soft lacustrine soils was modeled with and without artesian pressure, then the predictions were compared with the monitoring data. It was found that when artesian pressure was considered, the predicted settlements, lateral movement and excess pore pressures were higher than that of soft soils without artesian pressure; Therefore, controlling the magnitude of the consolidation process. This is mainly attributed to slow shear strength development during the embankment construction on the PVD improved soft soils. Furthermore, numerical results showed that when including an artesian pressure of 40 kPa during the back-analysis, the predictions were matching well the measured deformations in short and long term.