2026 Volume 21 Issue 2 Pages 253-267
To enhance the resilience of river levees against overtopping that exceeds the design high water level, technological development of self-supporting levee structures is being actively pursued. By clarifying the effects of hydraulic-induced changes caused by overtopping on the structural stability of such levees, it becomes possible to establish rational design approaches for various types of deformation that may occur under these conditions. Initially, a deformation chain diagram was constructed to systematically identify and organize the deformation phenomena associated with overtopping, including their causal relationships and underlying mechanisms. Subsequently, a trial design of the levee was conducted, incorporating a probabilistic model of geotechnical parameters that accounts for the uncertainty of the embankment and foundation ground based on soil classification. Finally, the concept of fragility curves was employed to quantitatively assess the influence of overtopping-induced deformations on levee stability. The analysis confirmed that poor interface compatibility between the soil and steel sheet piles has minimal impact on embankment stability, except in terms of seepage safety. In contrast, the loss of backfill material and the scour of the landward foundation ground were found to significantly compromise levee integrity.
