首先分析沉井结构在施工过程中的受力 ,根据耗散函数的拉格朗日方程建立沉井结构下沉的动力学模型 ,可以很好地预测一定开挖量下的下沉量。而一般的计算按静力平衡分析 ,受下沉系数的影响很大 ,预测的精度很大程度上受反馈信息的影响。所建模型有助于设计开挖量进程 ,也可根据工期的要求对沉井的自重设计提供修改意见。 Firstly, the stress of caisson structure during construction is analyzed. According to the Lagrange equation of dissipation function, the dynamic model of caisson structure subsidence is established, which can well predict the subsidence under a certain amount of excavation. The general calculation according to static balance analysis, by the sinking coefficient of a great influence on the accuracy of prediction is largely affected by the feedback information. The model can help to design the process of excavation, and can also provide modification advice on the design of deadweight of caisson according to the requirements of construction period.