Study on Limit States of River Levees Reinforced by Double Steel Sheet Pile Walls against Overtopping

Abstract

As in Typhoon No. 19 (Typhoon Hagibis) in East Japan in 2019, flood-induced damage on levees is expected to become more frequent and severe due to climate change and other factors. For such damage mitigation, resilient levees against overtopping are needed. One of the methods to realize this is to create a self-supporting structure in the core of levees using double steel sheet pile walls. However, the resistant mechanisms of such reinforced levees against overtopping from the start to the ultimate state have not been clarified, and design methods have not been established yet. Therefore, we identify the resistant mechanisms through a series of physical model tests on the reinforced levees subjected to overtopping by changing the steel sheet pile specifications (embedment depth and stiffness). The influence of the apparent wall height considering the scouring on the protected side on the deformation and stability of the double steel sheet pile walls is discussed. The test results and findings are expected to contribute to determining the limit states of double steel sheet pile walls in the levees against overtopping.