Discrete Element Modelling of Undrained Consolidated Triaxial Test on Cohesive Soils

Microparameters of the clay component of an earth fill dam need to be identified in order to develop a reliable discrete element landslide model. To characterize clay microparameters, a calibration process of matching the simulated and actual undrained consolidated triaxial test results were performed. Linear parallel-bond model was used to describe the interactions of clay particles. The microparameters calibrated to match the real clay behavior were particle stiffness, friction, bond stiffness, and bond strength. Sensitivity analysis revealed that bond stiffness and bond strength dictate the peak stress behavior of the numerical model, while particle stiffness and friction influence its critical-state stress behavior. The designed calibration methodology based from the sensitivity analysis results was able to identify a suitable set of microparameters that can simulate the real behavior of clay. Integrating the calibrated microparameters to the numerical model yielded good agreement between the measured and simulated stress-strain relationships of clay at different consolidation pressures.