Abstract: An efficient and stable sinking is the goal of the sinking large-span bridge caisson foundations during the construction. This paper presents a case history of a foundation project of the large caisson on the north anchorage of the Zhangjinggao Yangtze River Bridge. In order to ensure the safety and stability of the large caisson during the sinking process, a three-dimensional finite element analysis method was used to analyze the deformation and stress characteristics of the caisson structure under five typical working conditions. Combined with the caisson sinking coefficient, the corresponding caisson sinking coefficient values for different specific working conditions were determined, it can be used to guide the construction of caisson foundations. The analytical results indicate that the deformation and stress characteristics of the caisson foundation under five typical working conditions are within the design permission range. At the same time, compared with the previous estimation of the settlement coefficient using a one-stage process, the settlement coefficient estimated based on the specific working conditions can better reflect the safety and stability of the caisson foundation after being elevated and sunk under the current state, providing strong technical support for the design and construction of the caisson foundation.

Key words: Caisson Foundations, Finite Element Analysis, Sinking Coefficient, Technical Support