Geotechnical Stability Analysis of Earthen Levees in the Face of Uncertainty

Earthen levees are critical civil engineering infrastructures in the U.S. Many of them are beyond their design life and it is important to evaluate their safety and reliability for mitigation of any potential hazards. Traditionally, the stability of the earthen levees has been investigated using the deterministic analysis in terms of factor of safety. Recently there is a trend to utilize probabilistic methods for assessing the stability of earthen levee problems since significant uncertainties exist in the earthen levee analysis. Typically in a geotechnical engineering project only limited field investigation is conducted. The input parameters for stability analysis of earthen levees can be highly uncertain. To explicitly consider the uncertainties, this paper develops a framework for probabilistic assessment for the safety of earthen levees using the fuzzy finite element method. The strength reduction method is adopted for evaluating the safety of the levee and then the probability of failure for the levee is derived based on the fuzzy set based reliability method comprehensively considering the uncertainty in the input parameters. The derived results can provide valuable information about risk assessment and risk informed decision making for the stakeholders of earthen levees. A case study is presented to demonstrate the significance of the proposed framework for probabilistic assessment of earthen levee stability.