高拱坝地震损伤破坏的数值模拟

本文在假设混凝土宏观均质的基础上考虑细观不均匀性的影响,采用带残余强度的双折线损伤演化模型和带幂函数下降段的损伤演化模型,结合带拉伸截断的摩尔-库仑破坏准则,探讨了高拱坝在地震作用下的裂缝扩展和破坏形态.某即将兴建的拱坝的计算结果表明,混凝土大坝破坏主要由拉应力引起,开裂从坝顶中部开始,裂纹主要出现在坝体上部,其余部位基本保持完好.计算结果得出的最终破坏形态与模型试验基本一致.

Numerical simulation of damage in high arch dam due to earthquake

Based on the assumption that concrete is macroscopic homogeneous the cracking evolution process and damage mode of high arch dams are studied in consideration of the heterogeneity of concrete in meso scale. The bilinear damage evolution model and damage evolution model expressed in power function with descending section are adopted to combine with Mohr Coulumb criterion to investigate the crack development and fracture mode of high arch dam under the action of earthquake. The analysis result of a high arch dam in China under design shows that cracks taken place in concrete are caused by excessive tensile stress. The cracks initiate at the middle of dam top and distribute at the upper half of the dam with the rest part remained intact. This conclusion agrees with the model test result.