【作者】 谢洪；

【导师】 刘建军；

【作者基本信息】 石河子大学 ， 水工结构工程， 2008， 硕士

【摘要】 我国拥有的土石坝数量居世界第一,而其失事率亦居榜首,可以说大坝风险,土石坝尤为突出。本文详细阐述了风险分析的基本概念、理论与计算方法。针对传统的风险分析只考虑不确定性中的随机性,没有考虑不确定性中还包含有模糊性,提出应充分考虑随机性和模糊性,进行模糊风险分析,从而运用风险分析理论与模糊数学知识建立模糊风险计算模型,并采用水平截集将模糊变量模糊化处理为非模糊量后运用传统的风险计算方法求解模糊风险概率。本文主要研究内容包括:在综合分析了影响土石坝失事的各种因素随机性和模糊性的基础上,针对土石坝工程特点,通过对其失事模式的分析,应用模糊风险分析理论,建立了土石坝坝体失稳、超标洪水漫顶失事的模糊风险模型,得到以下主要结论:1大坝风险分析在对大坝的监测、评价和提高安全性方面的工作中将起着越来越重要的作用。2影响土石坝坝体失稳风险的因素很多,忽略变量间的相关性,计算结果偏于安全。3考虑了设计参数和失效准则的模糊性后,得出的风险对应于每一个值,都是一个区间值,反映出大坝从安全状态到失稳破坏状态是一个逐步发展的过程。在大坝风险分析中,充分考虑各因素不确定性中的随机性和模糊性,所得风值为区间值,该区间值较传统的风险确定值更合理,更符合工程实际,因此对大坝进行模糊风险分析是可行的。更多还原

【Abstract】 China is the country,which has the most amount of the earth dam throughout the world,and the same to the cases of accidents,among them,the earth dam safety is especially serious. This paper introduces comprehensively the basic theory and calculation methods of risk analysis. In view of the absence of fuzziness analysis in the traditional risk analysis, fuzzy risk analysis, which, together with randomness, constitutes the two inseparable uncertainty elements, deserves exposition. Based on the theory of risk analysis and fuzzy mathematics, three calculation models of fuzzy risk are established and solution is presented. This solution transforms fuzzy variables into random variables by level cut set so that fuzzy risk can be calculated with traditional risk calculation methods.The main contents as follows: In view of the great number of earth dams, the high proportion of dam failure in China, and seepage failure, instability and overtopping are the three main modes to dam failure, this paper puts emphasis research on thereinafter several aspects1 Dam risk analysis will play an increasingly important role in the dam of the monitoring, evaluation and improve the safety of the work.2 There are a number of factors, which impact the dam embankment, if it ignores the correlation between variables, the results will be preference to security.3 After considering the design parameters and criteria for the failure of fuzzy, the risk that corresponds to a value of each is an interval, reflecting the dam from the security status to a state of instability gradually undermine the development process.With randomicity and fuzziness adequately considered in the dam risk analysis, risk falls into circumscription category, and it is more reasonable and in more accordance with actual engineering compared with the tradional risk determinative value. So it is practicable to analyze the fuzzy risk of earth dam.更多还原