Study On Operation Safety Risk Analysis Method Of Dam

In recent years, the center of dam safety management in China is transformedfrom “engineering safety” to “engineering risk” with the socio-economic developmentand the improvement of public self-protection awareness. Risk analysis andmanagement of the dam not only considers the engineering safety of dam, but alsoconcerns more about the influence of the dam on public security. It is more in linewith the human-centered scientific development outlook and has an importantmeaning and practical value to protect the dam safety and realize the harmonioussociety in China with further research in this area. On the basis of analyzing andsummarizing the methods and techniques of the dam risk analysis at home and abroad,the establishment of dam risk analysis system and its risk analysis methods are studiedin the paper. Main contents are as follows:(1) Based on the in-depth analysis of current problems in the dam risk analysis,combined with the actual situation in China, the dam risk analysis system is discussedand its structure, main contents and analysis process are proposed.(2)The causes set of dam accidents, accident mode set and path set are giventhrough the statistical analysis of dam accidents at home and abroad,. The paperfocuses on the research of dam risk identification methods, introduces improvedIAHP (interval analytic hierarchy process), designes a reasonable weight model andsolution techniques, explores the dam accident modes and paths, identifies the mainaccident modes and paths and develops the risk decision-making process based onIAHP.(3) Based on the research of dam risk analysis ideas at home and abroad andengineering safety analysis methods of complex system, the overall risk of the dam isestimated based on the event tree method, combined with the fault tree method, expertexperience method and reliability analysis. This paper focuses on the research of damrisk analysis method by reliability, proposes the single accident path, system accidentand the reliability analysis considering time-dependent effects, and develops the riskprobability estimation program based on MATLAB. (4) Based on the four main failure modes of embankment, the factors inrespective uncertainties are analyzed, the risk probability estimation modelconsidering stochastic water level, stochastic seismic force and other risk factors isestablished and the self-developed estimation program is used to solve the model.(5) Based on the fracture extended finite element analysis, the accident path ofgravity dam under the condition of strong earthquake is researched; the riskprobability estimation method for gravity dam system is proposed by the stochasticfinite element method and Ditlevsen bound method based on the response surface.(6) Considering the time-dependent characteristics of uncertainties in safetyoperation of the dam, based on the time-dependent reliability theory, thenon-stationary time-varying random process is subject to stationary processing, thesingle-factor function and multi-factor integrated model with time-dependentstochastic quantization are established, and the computation model for time-dependentrisk probability of operation safety of dam is given. The introduction oftime-dependent effects to the dam operation safety assessment is beneficial toevaluate the technical service life of engineering structure and provide reference forstructure maintenance decision.