Research On The Break-dam Risk Analysis Of The Earth And Rockfill Dam Based On The Fuzzy Event Tree Method And Fuzzy Comprehensive Evaluation Method

Our country is a great nation of building dam, it is the fastigium for the dam construction after the nation’s establishment especially in the 50 ~ 70 s of the 20 th century, due to the technology and the special historical reasons at that time, it exists serious problems of ‘quantity’ ‘light’ and ‘quality’, people started building under the circumstances of the "trilateral"(surveying, designing, and constructing) and the ‘ four ambiguousness ’(the drainage area, the inflow, the storage capacity and basic geology survey failed to investigate thoroughly), even many projects had been completed, but the quality was very poor, leaving over a lot of potential safety hazard, coupled with operation management which couldn’t meet the requirement, thus it caused a lot of different levels of dangerously weak reservoirs even dam collapse, which made huge threat to people and the society. There are nearly 90000 reservoirs in China and nearly more than 30000 are operated with diseases, how to protect the safety of the reservoir and apply the limited funds to the most needed reinforcement reservoirs has become the priorities to consider For this problem, how to manage these dams with the risk analysis has became the urgent problem to solve in dam engineering industry.On the basis of reading a flood of literature, this paper summed up the status of internal and external dam risk analysis,it introduced the basic theory of relevant risk analysis particularly and analyze the advantages and disadvantages of the traditional calculation method,dam risk analysis is established on two aspects of the probability and consequential loss of dam failure, therefore, this paper combines the probability of dam failure and the consequential loss of dam failure, establishes the risk degree and it could be used a index for measuring the degree of risks, risk analysis method can be applied to both single probability and consequential analysis of the dam failure, it also can priority the risk after the quantitative risk analysis for dam group and dam failure thus to provide scientific basis for the implement of reservoirs reinforcement and rational allocation for optimizing capital.This paper studied the earth and rockfill dam and dam failure risk mainly from two aspects of risk probability and dam failure consequence.As to the aspect of risk probability, the traditional probability calculation generally only considers the randomness of the incident experience of experts, however, there are many ambiguousfactors that affect the dam failure, therefore in this paper based on the probability dam failure calculation of ambiguous event and the aspect of dam failure consequential loss, the previous seriousness of dam failure generally is the linear weighting among the factors of dam failure, there is big limitation for the ambiguity of factors, thus based on fuzzy comprehensive evaluation this article put forward to confirm the severity factor of dam failure consequence. Because we consider the ambiguity of factors when calculating the dam failure risk, the result quantitative index reflects the practical dangerous degree of huge dam more rationally. The research achievement will have certain significance of application to the risk analysis of dangerous reservoir dam.