Abstract: To study the evolution of dam collapse risk and prevent dam failure effectively, a dam collapse risk flow chart was establishes for the life cycle including survey design, construction and operation phases. On the basis of a certain tailings dam for ardealite tailings, the risk flow chart was used to reveal the dynamic evolution characteristics of life-cycle dam-break risk. Effects a given enterprise risk early-warning value and a given risk investment scheme can have on the dam-break risk were also investigated. Results show that the risk of the overall dam collapse increases over time, that at the stage of survey design, the risk increases linearly between 40 and 55 months, and the risk rate changes parabolically, that the dam-break risk increases step-by-step at construction stage, while during the operation phase, the risk of dam-break rises wave upon wave and reaches the maximum at the 60th month, that the corporate risk warning value has a significant impact on the risk prediction of dam, and that the increase in risk investment at the survey design stage is helpful to reduce and control the dam risk.

Key words: tailings dam, life cycle, tailings dam-break risk, risk evolution, system dynamics(SD)