冻错曲冰湖溃决风险及坝体稳定性研究

Study on the Risk of Outburst of Dongcuoqu Lake and Stability of Barrier Dam

随着交通建设和水电开发等人类工程活动不断向西藏高海拔地区推进,高海拔冰湖溃决洪水及泥石流问题出现。笔者首先通过野外地质勘察、室内遥感解译对西藏洛隆县冻错曲冰湖的溃决风险进行研究,然后运用Geo-studio软件分析了堰塞坝的抗滑稳定性。结果表明:冻错曲冰湖堰塞坝结构稳定,渗透性好,坝体未发生明显变形,汛期和非汛期冰湖面积变化小,溃决概率为0.42,溃决可能性较小。在非汛期、汛期和汛期叠加冰雪融化三种工况下,稳定性系数分别为1.311、1.197和1.057,坝体处于基本稳定状态。研究结果可为西藏地区冰湖堰塞坝稳定性分析和工程建设提供参考。

With the development of human engineering activities,such as transportation construction and hydropower development in high altitude areas in Tibet,a large number of glacier lakes are facing the problem of breaking flood and turning into debris flow.In this paper,field geological survey and indoor remote sensing interpretation,which were used to study the risk of outburst of Dongcuoqu Lake in Luolong County,Tibet.Then use Geo-studio to analyze the anti-sliding stability of the barrier dam.The results show that the barrier dam of Dongcuoqu Lake has stable structure,good permeability,and no obvious deformation.The area of the lake in the flood season and non-flood season changs slightly,the probability of outburst is 0.42,and the probability of outburst is small.There are three conditions,non-flood season,flood season and flood season superimposed ice and snow melting,the stability coefficients are 1.311,1.197 and 1.057,and the dam is in a basically stable state.The results can be used as a reference for the stability analysis and engineering construction of the glacier barrier lake dam in Tibet.