非线性拱坝-地基动力相互作用的 FE-BE-IBE 模型

同时考虑了高拱坝地震反应中的两个重要因素，即拱坝—地基动力相互作用和横缝非线性影响，并采用子结构技术加以实现，在拱坝地震反应分析中较以前有重大改进。由边界元—无限边界元耦合模型得到的地基频域动力刚度通过拟合法转换成时域离散参数，得以与拱坝有限元相耦合并在时域中求解。地震输入采用一种简化模型，在考虑无限地基辐射阻尼的同时避免了地震通过基岩后的人为放大。计算表明地基辐射阻尼对拱坝地震反应有显著影响。

Model of FE BE IBE coupling for soil structure interaction on nonlinear response of arch dams

In order to analyze the earthquake response of high arch dams, the effects of dam canyon interaction and that of local nonlinearity of the contraction joint opening, are considered and combined into one program for the first time through the substructuring technique. For modeling of rock canyon, the discrete parameters are obtained based on a curve fitting, thus allowing the nonlinear dam system to be solved in the time domain. A simplified earthquake input procedure is also used, which takes into account the radiation damping of the infinite canyon while preventing the artificial amplification of the ground motion through the rock mass. An example of the Big Tujunga Dam is given to draw some conclusions that the opening of contraction joints is inevitable leading to a substantial reduction of tensile stress in arch direction, and consideration of the infinite mass foundation with radiation damping results in the obvious reduction of the responses of the arch dam. These results demonstrate the significant effects of the above mentioned two factors on the response of the structure.