采用有限元方法对三峡三期上游RCC围堰与混凝土纵向围堰接头块进行了应力及稳定分析。重点分析了接头块在水压力、扬压力等主要荷载作用下的变形场和应力场，对接头块之间的接缝灌浆、考虑止水与不止水等方案进行了比较计算，在此基础上对建基面进行了局部和整体抗滑稳定分析。计算表明：接头块受扬压力和止水影响明显，并有一定的抗滑稳定安全度。

In this paper, the stress and stability of the joint blocks between RCC cofferdam in the third stage construction of the Three Gorges Project(TGP) and longitudinal concrete cofferdam are computed using finife element method. The major calculations include the deformation and stress fields of joint blocks under the action of main loads such as water pressure and uplift pressure. The effects of joint grouting among blocks and water seal are studied respectively. Based on above computation, overall and local stability of resistance to sliding on the foundation surface are analysed. The calculation results show that the effects of uplift pressure and water seal on joint blocks are obvious, and the joint blocks possess enough safety degree of resistance to sliding.