中文摘要：

为了更准确地评价火灾后混凝土桥梁的安全服役性能，建立了高温场结构响应模式，研究了模糊理论和棚划隶属度。以现有火灾场模糊综合评判方法为原型，引入指数建立指数隶属度，调整样本宽度以达到优化权距的日的，提出了优权评判方法，对工程算例进行了分析，验证了其评判精度，并对其进行了安全评价。研究表明，该方法能有效缩小温度的判定差距，减小多种方法对火灾场温度推测数据之间的离散程度及方差分布。在火灾后桥梁服役功能安全评价方面，优权评判方法相对于其他方法所得到的计算值更接近目标值，优权评判方法适合于火灾高温场的测区温度判定、灾后结构变形的评价及服役功能的安全评价。

英文摘要：

This paper is aimed at presenting our accurate evaluation model for the performance and safety of concrete bridge after a fire accident. Firstly, the objectives of structural response model that we have proposed are to determine the variation in the relationship of ultimate bearing moment with extending-fire time for concrete bridge, to determine the variation in the relationship of structural deformation with extending-fire time for concrete bridge and to determine the variation in the relationship of structural stress with extending-fire time for concrete bridge, on the basis of temperature value and extending-fire time. Secondly, we have also studied the fuzzy theory and the relative degree of membership. At the same time, we have taken the fuzzy comprehensive assessment method as the prototype in the fire temperature field and introduced the index number to build the index degree of membership. The sample width is adjusted to build optimal weight distance. Then, we have proposed the optimal weight discrimination method to compute the sample distance by a series of iteration. To note, we have tested the accuracy of the optimal weight discrimination method by the iteration distance of adjacent optimization weight. In case the iteration difference value among the iteration distances of adjacent optimization weight is large, the iteration will be proceeded; if the iteration difference value among the iteration distances of adjacent optimization weight is small, the iteration will be stopped. In the end of this paper, we have analyzed the actual engineering calculation in a fire accident by using the six proposed methods and the optimization weight discrimination method. The accuracy of discrimination is tested. The studied results indicated that ： （ 1 ） we can effectively diminish the discriminative difference of temperature and decrease the dispersion degree of presumption data in a high temperature field by using the optimal weight discrimination method; （2） In the aspect of assessing the performance