重力坝抗震性能熵权可拓物元评价研究

Seismic extension matter-element evaluation of gravity dam based on Entropy Weight Method

针对目前混凝土坝抗震安全评价缺乏统一标准,综合评价模型忽略了指标间评级分界不同导致分级程度不明确等问题,文章通过建立三维坝体-坝基塑性损伤有限元模型进行设计、校核工况下的响应计算;选取整体损伤指数、坝顶相对于坝踵的顺河向位移、坝基交界面屈服比作为指标,建立可拓物元模型,并应用信息论中的熵理论对指标赋权,确定大坝抗震性能评价等级。将基于熵权法的重力坝抗震性能可拓物元评价方法应用于西南某水电站工程。结果表明,重力坝地震破坏主要集中在坝踵、上下游折坡处,采用单一指标的评价结果出现指标间矛盾,而采用可拓评价能全面给出重力坝抗震性能评级,为准确评估重力坝抗震性能提供一种行之有效的方法。

In view of the lack of a unified standard for the seismic safety evaluation of concrete dams at present,and the comprehensive evaluation model ignores the problems of unclear classification degree due to the different rating boundaries between indicators,this paper establishes a three-dimensional dam body-dam foundation plastic damage finite element model to simulate design conditions and MCE load.The overall damage index,the displacement of the dam crest relative to the dam heel along the river,and the yield ratio of the dam foundation interface are selected as indicators to establish an extension matter-element model,and the entropy theory in information theory is used to weight the indicators to determine the maximum dam seismic performance evaluation grade.The Extension Matter-element Evaluation Method for the seismic safety of gravity dam based on Entropy Weight Method is applied to a hydropower station project in southwest China.The results show that the earthquake damage of gravity dam is mainly concentrated in the dam heel and the upper and lower slopes.However,the use of extension evaluation can give a comprehensive rating of the seismic performance of gravity dams,which provides an effective method for accurately evaluating the seismic performance of gravity dams.