Study On Indexes System Of Risk Analyis Of Discharge Structures And Flood Discharge Calculation Based On Concrete Dam

Safety evaluation for water storage is necessary basis of water impoundment of large-scale hydropower projects. However, conclusion of safety evaluation still depends on qualitative analysis. So, in order to have a further level of dam government and insure safety operation of hydropower dam, study on risk quantity-analysis must be enhanced. Research on risk analysis must be based on establishing reasonable indexes system. Now, some indexes system for earth rock dam is based of fuzzy theory and amount of monitoring datas. So, it is limited to be applied into practice. In This paper, it is discussed that how to establish risk-analysis indexes system of flood discharge structures for concrete dam based on lack of monitoring data, and how to measure the flood discharge risk furtherly.Firstly, this paper reviewed main causes of dam failure and hydraulic accidences at home and abroad, and carried out that classification of risk factors. Compared with other indexes system, and referring the relative standards, it is initially established of generally risk-analysis indexes system of concrete dam based on Hong jiang hydropower station.Secondly, this paper introduces measurement method of quantity factors and discusses measurement and weighting of indexes system. Compared with different method, Analytic Hierarchy Process (AHP) is adequate for risk indexes of flood discharge. So, its application into hydro engineering is discussed.Finally, this paper researches methods of hydraulic risk analysis in flood discharge structures of concrete dam. For solving the problem of many random variables of nonnormal distribution, JC method is applied to calculate flood discharge risk, which is carried out by FORTRAN language. Take Hong jiang hydropower station as an example, flood reasing risk is calculated based on JC and Monte Carlo method. Results presented that Monte-Carlo simulation took about 6 hours, while JC simulation took only 20 minutes. Difference of two menthods is 2.6%, however, the main advantage of JC is that it requires shorter time than Monte-Carlo simulation, and can meet accuracy demands of engineering. So, it is feasible tocalculate flood risk by JC simulation.Calculation results of flood discharge risk of Hongjiang hydropower station also show: (1) Calculation results of flood discharge risk rise, while considering hydraulic risk factors. (2)Considering effect of geometry dimension, about 45.6% of flood discharge risk is increased.so, it is necessary to insure the accuracy of construction. (3)Quantitative analysis of flood carrying Capicility show that capacity of flood realsing of hongjiang hydropower staion is safe.