用基于流形元的子域奇异边界元法模拟重力坝的地震破坏

SEISMIC FAILURE SIMULATION OF GRAVITY DAM BY MANIFOLD BASED SINGULAR BOUNDARY ELEMENT METHOD

本文提出了用流形无法和子域奇异边界元法相结合模拟结构地震响应及地震破坏的方法。流形元法的独特的网格及接触的处理方式，使该方法不仅可以象有限元法那样精确地分析结构的变形和应力，还可以象ＤＤＡ、ＤＥＭ等不连续分析方法那样模拟不连续面的接触和块体的运动．本文将Ｎｅｗｍａｒｋ法引入流形无法，使得该方法可以直接用来分析动力学问题。与作者提出的子域奇异边界元法相结合，可以模拟裂缝沿任意方向扩展及结构的地震破坏问题。对Ｋｏｙｎａ重力坝进行了地震破坏模拟分析，很好地再现了该坝的破坏过程，模拟破坏形式及裂缝出现的位置与实际调查结果、实验结果及其他学者用模糊裂缝模型得到的破坏结果吻合良好。

A method based on the combination of Manifold and Singular Boundary Element Method to simulate seismic response and failure processes of structures is presented. By a unique arrangement of numerical meshes and treatment to contact, Manifold Method is not only able to analyzed accurately the displacements and stresses of structures as FEM, but also to model the contact of discontinuities and the movement of blocks as discontinuity analysis method like DDA and DEM. Newmark method and the singular BEM proposed by the authors are combined into Manifold Method to analyze the seismic responses and the failure processes of structures. As an example, the failure process of Koyna dam in India caused by earthquake is analyzed, and a reasonable agreement with the in-situ investigation and other available results is reached.