Sudden flooding is one of the major risks for the drainage sinking construction of deep-water caisson. The damage of inner walls due to hydraulic pressure induced by sudden flooding threatens the labor and structural safety. This study developed the numerical model and analytical method to assess the hydraulic pressure on the inner walls of both the balanced and sudden-sinking caisson under sudden flooding risk. An experimental program of sudden flooding into a caisson specimen was conducted in a water basin to validate the numerical model and the analytical method for balanced caisson. The numerical and analytical methods were then illustrated by an actual engineering practice to show the hydraulic pressure on the inner walls for the caisson under balanced and sudden-sinking state, respectively. The experimental validation and engineering illustration prove that the numerical model is effective in the assessment of hydraulic pressure of caisson under sudden flooding, especially for the complicated case that includes the turbulence effect and sudden sinking, while the analytical method can calculate the quasi-static value of the hydraulic pressure more efficiently. The presented methods provide the engineers with alternative tools to learn more about the sudden flooding risk of the deep-water caisson.

突如其来的洪水是深水沉箱下沉施工的主要风险之一。突然的洪水引起的液压压力造成的内壁损坏威胁着劳动和结构安全。本研究建立了数值模型和分析方法，以评估突然发生洪水的平衡沉井和沉沉沉井内壁上的水压。在流域内进行了一次向沉箱标本中突然注水的实验程序，以验证平衡沉箱的数值模型和分析方法。然后通过实际工程实践说明了数值和分析方法，以分别显示沉箱内壁在平衡状态和突然下沉状态下的液压压力。实验验证和工程实例证明，该数值模型对沉井突水条件下的水压评估是有效的，特别是对于湍流和下沉等复杂情况，其解析方法可以计算出准静态值。液压的效率更高。所提出的方法为工程师提供了替代工具，以更多地了解深水沉箱的突然浸水风险。