Reliability analysis of compacted embankment with geocomposite under infiltration

Abstract

Embankment failures can be prevented by introducing geocomposites to act as drains. The effect of the geocomposite layer on the pore pressure distribution and surface displacements of an unsaturated embankment upon infiltration has been studied numerically using deterministic and probabilistic approaches. The inclusion of the geocomposite layer leads to an increase of suction below the interface and a decrease in suction above it by functioning both as a capillary barrier and a drainage layer, thereby reducing the surface displacements upon infiltration. The load in the form of rainfall and the resistance such as suction of the embankment material being variable leads to a variability in the displacements; therefore, reliability analysis has been carried out using hydraulic permeability and soil water characteristic curve (SWCC) parameters as random variables. To assess the probability of failure (Pf), a surrogate model based on augmented radial basis function has been used. Probabilistic analysis revealed that the embankment with geocomposite has less Pf compared to the embankment without geocomposite considering the rainfall infiltration. Moreover, sensitivity analysis predicted that SWCC parameters influence the Pf of embankment containing geosynthetics under infiltration to a larger extent.