Failure Mode of Dike and Reinforcement Mechanism of Steel Sheet Pile during Storm Surge

Peng Ming; Zhang Jingliang; Zhu Yan; Li Shuang; Chen Fangjian

doi:10.3799/dqkx.2025.137

Abstract：To investigate the dike stability during the storm surge,this study analyzed the failure modes of the dike under varying water levels and wave heights and the reinforcement mechanisms of the steel sheet piles on the dike based on the flume tests.The experimental results indicate that unreinforced dike failed at low water levels and high wave heights,following a failure process:seepage and overtopping,landward slope sliding,vertical wall tilting,and dike crest scouring.The single-row steel sheet pile kept the dike basically stable by reducing the internal seepage under low water level and high wave height conditions.At high water levels and middle wave heights,the dike eventually failed with a similar failure mode compared to the unreinforced dike.However,the single-row steel sheet pile blocked the headward scour caused by overtopping waves,mitigating the wave scour on the dike crest and generating obvious deformation with a significant increase in the maximum bending moment.The double-row steel sheet piles further reduced seepage and wave scour at high water levels and middle wave heights,and the dike remained stable basically with only several fence panels slipping.At high water levels and wave heights,the seaward pile and landward pile blocked the wave scour on the dike crest caused by waves in front of the dike and wave overtopping behind the dike,respectively,maintaining the dike and vertical wall stability.The maximum bending moments of the double-row steel sheet piles were smaller with deeper locations due to the limitation of the tie rod on the deformation.This research indicated that the single-row steel sheet pile improved the dike stability by reducing seepage and blocking the headward scour caused by wave overtopping.The double-row steel sheet piles reduced seepage and headward scour more effectively and blocked the wave scour in front of the dike,making the dike crest remain stable under the most extreme conditions.