Research On Analysis Of Fuzzy Risk In Dam Safety

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.