长江三峡工程二期深水围堰是该工程最重要的临时建筑物之一，它的设计和施工也是三峡工程的重大关键技术项目之一。二期围堰特定的条件和任务，决定了它的技术难度达到世界水平，在某些方面甚至超过世界水平。这些难点主要反映在：①围堰最大填筑水深达6Om，由此引起可能的堤头 The Second-phase Deepwater Cofferdam of the Three Gorges Project is one of the most important temporary structures in the project. Its design and construction are also one of the major key technical projects of the Three Gorges Project. The specific conditions and tasks of the second phase cofferdam have determined that its technological difficulty has reached the world level and in some respects even exceeds the world standard. These difficulties are mainly reflected in: ① cofferdam maximum fill water depth of 6Om, which may cause possible dikes