突变理论在某重力坝建基面失稳判据中的应用研究

摘要

The rationality of catastrophe criteria of displacement, plastic zone area and plastic strain energy for gravity dam along foundation interface are compared, and the calculation results of three catastrophic models of fold, cusp and swallowtail for a project case are compared and the applicability of these models are also analyzed. The calculation method of catastrophic criteria based on ideal elastic-plastic finite element is proposed. The calculation results show that the catastrophe criteria of plastic zone size or plastic strain are more reasonable than displacement catastrophe criterion, the cusp and swallowtail catastrophic models have higher precision than the fold model, and the calculation amount of cusp catastrophic model is much smaller than swallowtail model and the cusp catastrophic model is more reasonable and effective tool to study gravity dam instability along foundation surface.%对比分析了重力坝沿建基面失稳的位移突变判据、塑性区面积突变判据、塑性应变能突变判据三种判据的合理性，通过工程实例对折叠突变模型、尖点突变模型和燕尾突变模型的计算结果和可行性进行了比较分析，提出了基于理想弹塑性有限元计算的重力坝沿建基面失稳判定方法。结果表明：用塑性区面积突变判据或塑性应变能突变判据进行重力坝沿建基面的稳定性判定比采用位移突变判据计算结果更为合理；用尖点突变模型和燕尾突变模型进行重力坝沿建基面的稳定性判定计算比采用折叠突变模型结果更为合理；采用尖点突变模型的计算量比燕尾突变模型小很多，是研究重力坝建基面失稳的较合理有效的突变模型。