【摘要】 基于多座溃决堰塞坝案例的调查,对堰塞坝的形成机制、溃决风险及其影响因素进行分析总结,认为堰塞坝主要是由地震或降雨或火山喷发引起的山体滑坡、崩塌、泥石流所形成,形成方式可概括为滑坡、崩塌、泥石流以及碎屑流,其中滑坡是形成堰塞坝最主要的形式。堰塞坝的工作条件、坝体几何特征以及坝体物质组成和内部结构都与人工土石坝存在明显差别,其溃决的可能性远高于人工土石坝。指出堰塞坝的溃决风险主要取决于上游来水量、坝的拦蓄水量、坝的几何尺寸和坝的结构与物质组成,并讨论了降低堰塞坝溃决风险的应对措施。鉴于堰塞坝极高的溃决可能性与严重的致灾后果,建议今后加强堰塞坝溃决机理、溃坝过程的试验与数值模拟研究工作,提出能合理反映堰塞坝溃口发展规律、溃坝洪水流量过程的数值模型与相应计算方法,为科学预测堰塞坝溃决致灾后果,制定堰塞坝溃决应急预案提供技术支撑。更多还原

【Abstract】 Based on the investigation of several broken barrier dams,the formation mechanism,breaching failure risk and impact factors were analyzed.The barrier dams were regarded to be formed by landslides,collapses and debris flows caused by earthquakes,rainfall or volcanic eruption.The modes of formation of barrier dams could be categorized into those by landslides,collapses,debris flows and clastic flows,among which the mode of formation aroused by the landslides should the uppermost.There were obvious differences in the working conditions,characteristics of dam and substance composition,and internal structures between barrier dams and artificial earth-rock dams.The breaching failure risk of the former was much higher than that of the latter and mainly depended on the upstream flows,water storage,geometrical sizes as well as structure and composition of materials.The countermeasures for the reduction of the breaching failure risk were discussed.In view of great possibility of dam break and serious catastrophic consequences,it was suggested that the studies on the failure mechanism and the experiments on the process of the dam breach should be strengthened,and reasonable numerical models and evaluation approaches for the process of breach development and flood discharge should be proposed so as to evaluate the consequences due to dam break and to provide technical support for emergency plans of barrier dams.更多还原