土石坝二维地震反应有限元计算的影响因素研究

用有限元法计算土石坝地震反应时，有限元模型的网格剖分、计算边界的处理是计算精度的主要影响因素，也是有限元法分析前处理的主要工作。基于河海大学岩土工程研究所开发的二维有限元土石坝计算程序，分析了网格剖分的形式、网格的合理尺寸、简单边界的计算取值范围对土石坝地震反应的影响。研究结果表明，在土石坝地震反应计算中，网格剖分的整体形式应该水平成层，网格尺寸以最大坝高的7 %～10 %为上限；在有覆盖层的土石坝工程中，简单边界的计算区域应包括覆盖层，并与覆盖层厚度有特定的关系。上述成果可使前处理过程更严谨、更易操作，可作为研究和实际工程计算的参考。

Primary influence factors of 2D finite element calculation of seismic response for embankment dam

Mesh and boundany are primary influence factors of calculation procision when the seismic response of embankment dam is analyzed by finite element method. Based on the calculation program developed by the Institute of Geotechnical Engineering in Hohai Univ., the influences of mesh form, mesh size and boundary size on the calculation of seismic response of embankment dam are studied. The results show that mesh holistic form should be horizontally stratified, the upper limit of mesh size is 7 percent to 10 percent of dam height and the calculation area with simple boundary should contain the cover stratum.