基于贝叶斯框架下大坝服役性态综合评估方法

A Comprehensive Evaluation Method for Dam Service Behavior Based on Bayesian Framework

大坝服役性态的综合评估对水利枢纽的安全运行有重大意义。现有的评估模型存在过于依赖专家经验,缺乏客观性,或仅限于数据挖掘,未融入专业知识的不足。以贝叶斯网络为主要框架,提出了一种结合专家主观经验和客观实测数据的大坝性态评估方法。该方法根据朴素贝叶斯分类和BIC评分优化的方式确定网络结构,有效地厘清了影响因素之间的关系。利用模糊综合评价理论和熵权法分别求解先验分布和条件分布,运用贝叶斯估计进行推理,得到兼顾主观经验和客观数据的失效概率。结合失效概率等级表,对大坝服役性态进行有效的评估和定级。以某混凝土坝14个影响因素的时间序列为例,建立了该坝贝叶斯框架下多指标服役性态评估模型,并对其服役性态进行安全评级。最后从主观与客观、整体与部分、静态与动态3方面分析评估结果,证明了该方法的有效性。

The comprehensive evaluation of dam service behavior is of great significance to the safe operation of water control project.Current evaluation models are too dependent on expert experience,hence lack of objectivity,or limited by data mining in the absence of professional knowledge.An assessment method for dam performance is presented based on Bayesian network combining the subjective experience of experts with the objective measured data.The relations among influencing factors are clarified effectively by determining the network structure according to naive Bayesian classification and BIC score optimization.Furthermore,the prior distribution and conditional distribution are solved by using the theory of fuzzy comprehensive evaluation and the method of entropy weight.The failure probability involving both subjective experience and objective data is obtained via reasoning through Bayesian estimation.The service behavior of dam thus can be assessed and rated according to the rating of failure probability.A multi-index evaluation model for the service behavior of dam under the Bayesian framework is established with the time series of 14 influencing factors of a concrete dam as a cases study.The safe service behavior of the dam is rated.The validity of the method is proved by analyzing the evaluation results from subjective and objective,holistic and partial,as well as static and dynamic perspectives.