The objective of the research is to compare various features of partially-saturated soil models within a coupled small strain triphasic mixture finite element implementation to determine an appropriate constitutive modeling framework for partially-saturated soils. To achieve the objective, specific research tasks include: (1) formulating and implementing a small strain nonlinear triphasic mixture finite element in a Matlab code; (2) verifying the triphasic mixture element in Matlab code to partially-saturated water flow simulated by commercial codes and a closed-form solution; (3) formulating and implementing a small strain partially-saturated soil hyperelasto-plasticity model in the Matlab code; (4) using constitutive parameters from experimental data available in the literature; and (5) conducting plane strain finite element analysis of rainfall infiltration into slope surfaces with gravity loading. |