汶川地震堰塞湖安全实例分析

前人在对堰塞湖进行安全评价中,往往较少考虑到坝体级配、上游两岸山体的稳定性以及下游床面的结构.基于作者多次深入汶川地震灾区的考察调研,通过多个堰塞湖实例详细研究了上述因素对堰塞湖安全的影响,得出结论:坝体的级配会影响坝体自身的结构稳定性、溃坝水流最大流量以及渗透特性;两岸山体发生二次崩塌滑坡会增加堰塞湖溃决的危险;下游床而结构稳定性越高,河床越稳定,有利于堰塞湖的保存.还给出了表示坝体级配、两岸山体稳定性和床面结构的安全指标,提出了理想的堰塞湖安全评价的综合指标形式,为科技工作者更全面的对堰塞湖进行安全评价提供借鉴.

Safety Analysis of Dammed Lakes in Wenchuan Earthquake

There were few papers about the safety assessment of dammed lakes,regarding to the factors of gradation of blocked dam, stability of upstream mountain, and downstream bed structure, in the past. Based on the investigation of the disaster area induced by Wenchuan earthquake, three factors affecting the safety of dammed lakes were analyzed by several examples. Accoding to the analysis, the following conclusion were obtained. The gradation of blocked dam can influence the structure stability of the dams, the peak discharge of the dam break, and permeability. If the second geo-hazards such as collapse and landslide happen in upstream mountain, the dammed lakes will be danger. The stronger of downstream bed structure can increase the stability of the stream bed, and it is also good for dammed lakes conservation. The safety index of three factors was brought up, and the comprehensive index for the safety assessment of dammed lakes was also suggested.