地震共振涌浪作用下冰碛堰塞坝的漫顶溃决  

Overtopping Failure of Moraine Dams under Action of Earthquake-Induced Resonant Water Surges

作　　者：张聪 姚令侃[1,2,3] 黄艺丹[1,2] 苏玥 ZHANG Cong;YAO Lingkan;HUANG Yidan;SU Yue(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;MOE Key Laboratory of High-Speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;National Engineering Laboratory for Technology of Geological Disaster Prevention in Land Transportation,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031 [3]西南交通大学陆地交通地质灾害防治技术国家工程实验室,四川成都610031

出　　处：《西南交通大学学报》2021年第3期564-571,共8页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(41571004,41902302);中国科学院国际伙伴计划(131551KYSB20180042);四川省科技计划项目(2019YFG0001)。

摘　　要：为了研究冰碛坝在地震共振涌浪作用下的漫顶溃决机制,设计了振动台造波模型实验.首先,通过对比实验获取了地震共振涌浪运动规律和最大波高的影响因素,并通过量纲分析建立了共振条件下涌浪最大波高计算公式;其次,依据非均匀沙起动临界水头高度与溃坝输沙临界水量条件,建立涌浪作用下堰塞坝漫顶溃决临界条件与溃决风险评估程式;最后,以帕隆藏布流域川藏铁路交通廊道沿线34个小型冰碛堰塞湖为例说明评估程式的作业流程.研究结果表明:地震触发小型水体共振时涌浪运动幅度远超同等条件下的非共振涌浪幅度,且地震作用停止后涌浪波幅缓慢衰减,在共振涌浪时程曲线中存在稳态幅值持续运动阶段;当考虑地震共振效应后,帕隆藏布流域危险冰碛湖数量由3增至11,并在地震动水平地震加速度(PGA)较小区域均有分布;研究可为川藏铁路等沿线堰塞湖地震溃坝风险评估提供科学依据.Shaking table model experiments were designed to study the overtopping failure mechanism of moraine dams under action of earthquake-induced resonant water surges(ERWSs).Firstly,movements of earthquake-triggered surges under resonant and non-resonant conditions were compared to examine the main influencing factors of maximum height of ERWSs,and a prediction equation for the maximum height was proposed through dimensional analysis.Then,based on the critical water head condition for coarse particle initiation and the critical water volume condition for sediment transportation in dam break,critical conditions of overtopping failure for barrier dams under water surge actions were established and a risk assessment procedure was developed.Finally,taking the 34 small-scale moraine-dammed lakes located in the Parlung Zangbo River basin as examples,the operation of the proposed procedure was demonstrated.Results show that compared with non-resonant surges,ERWSs have greater amplitudes and a much slower process of attenuation with time,and a steady state with continuous large-amplitude wave motion exists in the time history of the resonant surge.When the seismic resonance effect is considered,the number of dangerous moraine-dammed lakes in the Parlung Zangbo River basin increases from 3 to 11,and the distribution extends to the areas with smaller peak ground acceleration(PGA).The results provide a scientific basis for seismic risk assessment of barrier lakes along the Sichuan-Tibet Railway.

关 键 词：地震 涌浪 共振 冰碛堰塞坝 漫顶溃决 

分 类 号：TV69[水利工程—水利水电工程]