堰塞湖关键工程措施快速、定量分析方法研究——以2018年“11.03”白格堰塞湖为例

Analysis of key engineering measures for barrier lakes:Taking the “11.03” Baige Barrier Lake in 2018 as an example

堰塞湖一旦失控溃决,将对下游造成极大威胁。其可供应急处置的时间极为有限,急需采取切实有效的应急处置技术,其中关键工程措施的选择尤为重要。在归纳总结国内外多座堰塞湖应急处置经验的基础上,选择基于物理机制的DB-IWHR溃决分析方法和参数化溃决分析方法结合白格堰塞湖实例开展关键工程措施对比论证。结果表明:物理机制分析方法能够快速、定量地确定堰塞湖关键工程措施——开挖引流槽。2018年"11.03"白格堰塞湖紧急开挖的一条长220 m、深15 m、顶宽42 m、底宽3 m的引流槽,可使堰塞湖库容由8.08×10^8m^3减小至5.79×10^8m^3,溃决洪峰流量由39 277.35 m^3/s减小至31 000 m^3/s。DB-IWHR物理机制分析方法快速实用,可在1 h内完成方案论证,适用于堰塞湖应急处置的快速、定量需求。通过与参数化溃决分析方法对比,表明物理机制分析方法具有更详细的结果,可为堰塞湖应急处置关键工程措施的确定提供科学支撑。

Barrier Lakes,if out of control,will pose a great threat to the downstream.Due to the sudden occurrence,the time available for emergency disposal is extremely limited,so it is urgent to take effective emergency disposal,of which the selection of key engineering measures is particularly important.By summarizing the experiences from the emergency disposal of many barrier lakes at home and abroad,we carried out a comparative analysis of key engineering measures using physically-based DB-IWHR breach and typical parametric breach methods based on the case study of Baige Barrier Lake.The results show that physically-based breach method can quantitatively and quickly determine the key engineering measure for the barrier lakes,which is the excavation of overflow channels.The overflow channel excavated in the crest of "11.03" Baige Barrier Lake in 2018 is 220 m long,15 m deep and 42 m wide at the top,3 m wide at the bottom.Excavating the overflow channel decreases the storage capacity of the lake from 39 277.35 m^3/s to 31 000 m^3/s and the breach volume of peak flood from 8.08 × 10^8 m^3 to 5.79 × 10^8 m^3,respectively.The DB-IWHR physically-based breach model is efficient and applicable,with this model the scheme demonstration can be done within 1 hour.It is suitable for the the emergency disposal of barrier lakes.By comparing with the three typical parametric breach methods,it is shown that the physically-based breach method has better performance and more detailed results,which can provide scientific support for the selection of emergency disposal for key engineering measures.