The cofferdam method is generally applied in the construction of underwater pier foundation in bridge engineering, and the pouring of bottom sealing concrete is one of the important links in the construction of the cofferdam. The bottom sealing concrete can prevent water seepage and balance the main body of the cofferdam, and its structural size and construction quality have a great influence on the above functions. Under the condition of large water level difference, it is difficult to determine the reasonable thickness of the bottom sealing concrete. There are few related studies in this field, and there is a lack of systematic summary of calculation theory. This work theoretically deduces the approximate solution of ultimate bending moment and ultimate stress of the bottom sealing concrete, introduces two different calculation methods, systematically summarizes the calculation methods of three kinds of ultimate stress, analyzes the calculation methods of ultimate bonding force, and uses ANSYS finite element software to simulate a specific bottom sealing concrete model, and compares it with the theoretical calculation results. The maximum stress obtained by the approximate solution is closer to the actual monitoring data than the traditional method, and the calculation method of the bonding force can be used to make a rough estimate.

中文翻译：

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水下深基坑底封混凝土极限承载力：理论计算与数值分析

桥梁工程水下墩基础施工中普遍采用围堰法，底封混凝土的浇筑是围堰施工的重要环节之一。封底混凝土可以防止渗水和平衡围堰主体，其结构尺寸和施工质量对上述功能有很大影响。在水位差较大的情况下，很难确定封底混凝土的合理厚度。该领域相关研究较少，缺乏对计算理论的系统总结。本工作从理论上推导出了封底混凝土极限弯矩和极限应力的近似解，介绍了两种不同的计算方法，系统总结了三种极限应力的计算方法，分析了极限粘结力的计算方法，并利用ANSYS有限元软件对特定的封底混凝土模型进行了仿真，并与理论计算结果进行了比较。近似解得到的最大应力比传统方法更接近实际监测数据，可用结合力的计算方法进行粗略估计。