A methodology for identifying and calibrating the material parameters for a coupled hydro-mechanical problem is presented in this paper. For validation purpose, a laboratory-based water infiltration test was numerically simulated using finite element method (FEM). The test was conducted using a self-designed column-type experimental device, which mimicked the wetting process of a candidate backfill material in a nuclear waste repository. The real-time measurements of key state variables (e.g. water content, relative humidity, temperature, and total stresses) were performed with the monitoring sensors along the height of cylindrical soil sample. For numerical simulation, the modified Barcelona Basic Model (BBM) along with soil-water retention model for compacted bentonite was used. It shows that the identified model parameters successfully captured the moisture migration process under an applied hydraulic gradient in a bentonite-based compacted soil sample. A comparison between the measured and predicted values of total stresses both in axial and lateral directions along with other state variables revealed that heterogeneous moisture content was distributed along the hydration-path, resulting in non-uniform stress-deformation characteristics of soil.@en

A water infiltration test was numerically simulated using the finite element method. The modified Barcelona Basic Model and the double-structure water retention model was used for the numerical analysis. A methodology is presented for parameter identification and calibration purpose. The experimental results highlighted the porosity redistribution and hydration-induced heterogeneity along the hydration-path. The simulation results successfully captured the moisture migration in the soil sample. A comparison between the measured and predicted total stress values revealed the influence of interfacial friction between the soil sample and cell wall.@en