Effect of Pile Modeling Options on the Short-Term Stability Analysis of a Clay Slope Stabilized with Piles

This paper investigates the effect of the pile modeling approach on the factor of safety of a clay slope stabilized with deep foundations using three-dimensional numerical analysis. The short-term stability was considered due to the surcharge load on the crest. In the analysis, the piles were modeled using both linear-elastic and elasto-plastic approaches for comparison purposes. The factor of safety, pile behavior, and pile internal forces were evaluated for each case. The results show that the linear elastic pile model does not allow the structural failure of the piles in factor of safety analysis that results in higher factor of safety than the critical failure mode of the pile-stabilized slope. Modeling elasto-plastic reinforced concrete piles without considering reinforcement resulted in early development of multiple plastic hinges, and hence it is a conservative approach. The results indicate that the approaches that use elasto-plastic reinforced concrete pile models provide a better analysis of the pile-soil interaction which allows the model to evaluate the factor of safety for the more critical failure mechanism of the coupled slope-pile system.