溃坝后果严重程度评价模型研究

Study on evaluation models of severity degree of dam failure impact

为了建立溃坝严重程度综合评价的定量模型,依据现行法规,采用建立数学模型的方法,分别分析并提出了决定大坝溃决后果严重性的3个主要影响因子(生命损失、经济损失和社会环境影响)的严重程度系数及其对数非线性和对数线性评价模型,构造了溃坝后果严重程度的综合评价模型。依据该模型,定量分析了5座水库大坝溃坝的严重性,给出了判别严重程度的定量指标。

Dam risk assessment technique has already been used in the field of dam safety management abroad especially in Canada, Australia and USA in receut twenty years. There are more than 85 000 darns in China and about one-third of them are with severe deficiency and in high risks. Therefore it is real necessary to use this kind of technique to assist prioritiziug darn maintenance or rehabilitation, reducing risks caused by dam failure. The technique consists of two important research objectives, dam-break probability analysis and dam failure impact evaluation. Dam failure impact includes three main factors： loss of life, financial loss, society and environment. How to evaluate the severity degree by means of these three factors comprehensively is a challenge of dam rehabilitation declsion-making. The paper is to present a comprehensive evaluation coefficient for dam-break severity degree. The study introduces integrative assessment function L which considered weights St respectively of llfe loss, financial loss, society and environment, and their severity coefficients Fi , formed as linear weighted sum method. In order to integrate loss of life, financial loss, society and environment in accordance with existing laws and regulations in China, logarithm non-linear or linear models of data normalization are established to deal with their different units, A series of quantitative values of L which divide disaster event into deferent degree are suggested according to Chinese situatial. The method and evaluation model is practically applied at 5 reservoir dams to appraise their severity degrec of failure impact respectively and the comparison of these results are made to decide which one is more severe. The analyzed result shows that hazard of all these 5 dams would be extreme severe and should report to State Council as soon as the event of dam break occur.