Risk Analysis For Levee And Application For Levee Of BANQIAO River

Risks in levee engineering caused by many uncertainty factors are cared about by people. The thesis is combined with the project "Research on risk analysis and risk management for left bank levee of Banqiao river in Nanjing" . Based on constituting computation model, the risk coefficients and theirs critical value for main invalidation codes of typical section are calculated through risk analysis method founded on reliability, comprehensive risk for flood prevention is analyzed and appraised. Measures of risk reduction and advice of floodwater level run management in flood season for levee are put forward based on risk management and decision-making simultaneously. The subject of the thesis comes from practical project, risk analysis models and methods are researched. The main contents are outlined as follows:Firstly, the definition and character of risk are introduced, the conception, purpose andprinciple of risk analysis are explained, the main contents of risk analysis are concluded;classification and analysis methods are researched, uncertainty factors in geotechnicalengineering and water conservancy are described; and computation methods for riskcoefficient are outlined.Secondly, invalidation mechanism of levee engineering is researched based on invalidation theory. Through analyzing risk factors which influence the safety of levee, event tree model is constituted. The main invalidation codes for dike are researched from the angle of engineering geology. Be based upon three main invalidation types: flood, seepage and slip of levee, the risk computation model are founded correspondingly. Simultaneously, the comprehensive risk computation model is researched by integrating three failure styles as upwards.Thirdly, combining with the project "Research on risk analysis and risk management for left bank levee of Banqiao river in Nanjing" , certainty and uncertainty analysis for seepage stability and slide instability of typical section of the dike are carried out, theirs risk coefficients are computed, critical values of seepage failure risk coefficient, slide instability risk coefficient and comprehensive failure risk coefficient are constituted for Banqiao river levee. Comprehensive risk for flood prevention and reinforced effect are analyzed and appraised systematically.Fourthly, risk management and decision-making for levee is researched from three aspects: the main contents of risk management and decision-making for levee, the divisional method of safety grade for levee and its technology development. Engineering and non-engineering measures of risk reduction for levee are outlined. Combining with the project of Banqiao river levee, measures of risk reduction and advice of floodwater level run management in flood season for levee are put forward based on the result of risk analysis and the permissible value of risk coefficient...