中文摘要：

汶川地震后，水工界众位学者对于我国水工建筑物的抗震标准和安全目标提出了新的观点及建议，并对《水工建筑物抗震设计规范》进行修订，明确了对于重要大坝，须按最大可信地震进行校核，以不发生溃坝作为安全目标。本文以待建的实际工程为研究对象，建立了考虑分离的双线性本构关系接触单元的全坝段三维有限元模型，研究重力坝在最大可信地震下的三维非线性灾变分析。通过分析极震情况下坝体的开裂、滑移，并评估坝体抗滑稳定性得到以下结论：在所设置的接触面如坝体一地基接触面、横缝以及下游折坡处的施工缝均发生了张开、闭合和滑移，但最大张开度和滑移产生的永久位移均在可接受范围。通过位移时程曲线收敛可以判断，大坝未发生溃坝现象。

英文摘要：

After Wenchuan earthquake, some experts have presented new opinions and suggestions for seismic criterion and safety target of hydraulic structure in our country and The specifications for seismic design of hydraulic structures is amended. This code emphasizes the importance of adopting maximum credible earthquake as a check condition for the safety of key dams against dam failure. This paper describes a 3D full-dam model for concrete gravity dam, using contact elements reflecting the debonding bilinear constitutive relation in combination with a case study of actual dam construction. Simulations of this gravity dam in MCE condition reveal its occurrence of cracking and sliding and its sliding stability under such extreme earthquake actions. In conclusion, opening, closing and sliding occur on all the contact faces such as dam-foundation contact faces, contraction joints and horizontal construction joints, while their peak values fall within acceptable ranges. The time convergence curve of dam displacement verifies that the dam is not in failure state.