随着西部地区一些大型水利枢纽工程的兴建，需要在深水中填筑高土石围堰，其防渗墙的设计和施工对土石围堰安全运行至关重。采用非线性有限元法，基于邓肯?张E－?本构模型，结合乌东德水电站工程，分析其土石围堰应力变形规律，并根据施工过程和不同影响因素，进行多种方案比较，研究了塑性混凝土防渗墙在围堰施工运行过程中的工作性态变化，论证了围堰设计的合理性，为该围堰施工和安全运行提供了一定参考依据。

With the building of some large-scale water control project in the western region, it is needed to fill the high earth-rock cofferdam in the deepwater, the design and construction of the cutoff wall is important to the safe operation of the earth-rock cofferdam. Based on the constituve model of Duncan E-? and combining with the project, this paper analyzes the law of the stress and deformation of the earth-rock cofferdam by adopting the method of the nonlinear finite element. According to the construction process and different affecting factors, the paper also studies workability changes of the plastic concrete cutoff wall in the process of cofferdam construction by comparing a variety of project. It demonstrates the rationality of the design of the cofferdam, and provides certain reference to the safe construction and operation of the cofferdam.