Reliability of Levees against Seepage Failure Considering Uncertainties of Soil Properties and Occurrence of Maximum Floodway Water Level

摘要

The present study is designed to estimate reliability against seepage failure of levees considering the uncertainty of geotechnical characteristics and the annual probability of floodway water levels at the same time. Its aim is to calculate the annual probability of levee failure caused by a circular slide due to a rise in the water level. For this purpose, a fragility curve was first obtained based on the probability of seepage failure using the stochastic finite element method with uncertain shear strength. Furthermore, a hazard curve of the annual exceedance probability derived from observational data on floodway water levels was determined. Using these results, the annual failure probabilities integrated at water levels were calculated. It was suggested that the safety of the levee could be quantitatively evaluated by the longitudinal distribution chart of annual failure probability. These charts can be used to set priority levels for maintenance and repair plans, etc.