【作者】 韩瑞芳；

【导师】 李宗坤；

【作者基本信息】 郑州大学 ， 水工结构工程， 2007， 硕士

【摘要】 我国是筑坝大国，拥有的土石坝数量居世界第一，而失事率亦居榜首，可以说大坝风险，土石坝尤为突出。遍布全国各地的大坝在国民经济发展中扮演着重要的角色。然而，大坝的潜在威胁也是巨大的，一旦失事就会给下游地区带来严重灾害，并且随着老坝、病险坝数量日益增加，大坝的安全问题越来越引起人们的关注，与此相应的大坝风险分析也在世界范围内迅速开展。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，而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a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。鉴于我国土石坝数量多，失事比重大，而土石坝坝坡失稳、坝体渗透破坏及超标洪水漫顶失事是土石坝失事的三种主要模式，本文对以下几方面进行了重点研究：1、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，建立了土石坝坝坡失稳、渗透破坏和洪水漫顶模糊风险模型。2、针对模糊风险数学模型难以运用解析法求解的特点，采用简化方法和离散化数值求解方法将其离散化后，根据Monte-Carlo方法的基本原理、运用MATLAB编制计算程序求解风险概率。3、将土石坝坝坡失稳、坝体渗透和超标洪水漫顶模糊风险模型应用于龙兴寺水库中，其计算结果和文献[56]大坝安全鉴定所得结果是一致的，从而验证了所构建模型的合理性和可行性、计算方法的正确性。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，所得风险值为区间值，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。由于目前尚无大坝失事模糊风险标准，本文按未考虑模糊性的风险标准进行安全评价。更多还原

【Abstract】 Our country is the big country of dam-maker. There is 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. The dams are found everywhere and play an important role in our economy development. But the potential hazard is also huge; once dams’ wrecks happen it will bring serious damage. Along with the old dams and the sick dams getting more and more, the dams’ security causes people’s high attention. Meanwhile the dams’ risk analysis is outspread rapidly through the world.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, calculation model of fuzzy risk is 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.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 aspects.1 After having synthetically analyzed the fuzziness and randomness of all factors, the seepage failure instability and overtopping fuzzy risk models of earth dam are established.2 The paper approaches the inapplicability of analysis method to the three above-mentioned mathematical models by using dispersed demoted numerical virtue method with Monte-Carlo method. Programs by MATLAB are worked out and used for calculating risk probability.3 Seepage failure instability and overtopping fuzzy risk models are used in the Long Xing Si Reservoir. The result is accordance with the Dam Safety Identify in the literature[56]. So the models is reasonable and feasible, the arithmetic is accurate.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 traditional risk determinative value. So It is practicable to analyze the fuzzy risk of earth dam. Because the fuzzy risk standard of dam failure has not been established, the traditional risk standard is used for the safety evaluation in this paper.更多还原