改进的模糊事件树法在土石坝溃坝风险评估中的应用

Application of improved fuzzy fault tree method in earth-rock dam failure risk assessment

基于模糊数的事件树法是近年来被提出的大坝风险分析方法.该方法采用模糊性语言描述专家对溃坝发展各环节发生可能性的判定,采用Delphi方法和判断矩阵法,将模糊性语言表示为三角模糊数,经解模糊处理得出各环节发生概率的定量值.为避免此过程中专家评判的主观性,引入熵技术对专家权重进行修正.对油罗口水库进行风险分析,构造副坝管涌这一失事模式下的溃坝事件树,运用改进的模糊数事件树法估算溃坝概率.工程实例结果表明,该方法切实有效.

The fault tree method based on fuzzy mathematic is a new method applied in the dam risk analysis in recent years.The fuzzy number is introduced to represent experts＇ qualitative judgments about the possibility of all the links in the dam failure development.Through the Delphi method and the determining matrix method,the judgment of experts is further converted into triangular fuzzy mathematic,which can obtain the quantitative probabilities by resolving the ambiguity of experts＇ fuzzy judgment.In order to reduce the subjectivity in this process,entropy technologies are introduced to amend the weight coefficient of the experts.Finally,this paper carries out a risk analysis of Youluokou Dam and attempts to construct a dam fault tree under the accident mode where piping occurs on the auxiliary dam.The improved fuzzy fault tree method is used to estimate the dam failure probability.The relevant application case shows that the method is feasible and effective.