事件树法原理及其在堤坝风险分析中的应用

介绍了事件树构建的原理和方法及分枝概率的计算方法。事件树法能灵活地处理自然界中的各种随机因素及认识不确定性，并可方便地把这些因素带入到结构系统的可靠性分析中，因此，其在堤坝风险分析中应用较广，国外应用较多。以一个实例介绍了事件树在堤防风险分析中的应用，实例考虑了堤防的3种可能破坏模式：漫顶、结构失稳、地基侵蚀。分析了堤防系统中的各不确定性影响因素及其定量求解方法，从工程实例中可以清楚地看出事件树法的优越性。

The constructing principle of event tree method and its application in risk analysis for dykes and dams

The constructing principle and method of the event tree is put forward and the probability calculation of branch events is introduced. The event tree method can easily take various kinds of random factors into consideration in reliability analysis of systematic structures. Due to its flexibility in dealing with natural variability and uncertain knowledge, the event tree method is widely used in the field of risk analysis for dykes and dams in countries such as Canada and Australia. A case study on a dyke risk analysis is given in this paper. Three failure modes are supposed, i.e. overtopping, structural stability failure and erosion of foundation. The uncertain factors influencing the given three failure modes and their quantification are interpreted in detail. The result of the analysis reveals the advantages of the event tree method in risk analysis for dykes and dams.