中文摘要：

大坝安全评价是一个多因素、多层次、具有复合不确定性的复杂综合评价问题.针对大坝安全监测信息中普遍存在的不确定性，将专门研究不确定性问题的云模型理论引入到大坝安全综合评价之中，提出了基于云模型的大坝安全多层次综合评价方法.该方法采用具有稳定倾向性的一组随机数代替具有唯一性的模糊隶属度，利用云发生器生成隶属云，得到由云模型数字特征刻画的、顾及监测信息不确定性的大坝安全综合评价结果.该评价结果不仅可以对大坝安全状态作出合理评价，而且可以描述大坝安全评价结果的可信性，以及不确定性给大坝安全评价结果带来的不稳定性.实例表明，本文所提出的基于云模型的大坝安全综合评价方法是合理、可行的，为大坝安全评价提供了一条比传统的模糊综合评价方法更优越的新途径.

英文摘要：

Dam safety evaluation is a complicated and comprehensive evaluation problem involving multiple factors, multiple hierarchies and compound uncertainties. Through the introduction of the cloud model theory specialized in uncertainty problems into dam safety evaluation, the paper makes a research on the ubiquitous uncertainties of dam safety monitoring data, and proposes a multi-hierarchical comprehensive evaluation method for dam safety based on cloud model. By using a group of random numbers with stable tendencies to replace definite fuzzy degrees of membership and utilizing cloud generators to create membership clouds, the approach obtains a comprehensive dam safety evaluation result characterized by numerical features of cloud model and considering uncertainty of monitoring data. It not only gives a reasonable assessment to the state of dam safety, but also shows the credibility of this evaluation result and instabilities for the result created by uncertainties. Compared with the traditional fuzzy synthetic evaluation approach, examples show that the comprehensive dam safety evaluation method based on cloud model proposed in the paper is reasonable, feasible and superior.