Numerical investigation of hydro-morphodynamic characteristics of a cascading failure of landslide dams  

作　　者：ZHONG Qiming CHEN Lingchun MEI Shengyao SHAN Yibo WU Hao ZHAO Kunpeng 

机构地区：[1]Department of Geotechnical Engineering,Nanjing Hydraulic Research Institute,Nanjing 210024,China [2]National Key Laboratory of Water Disaster Prevention,Nanjing 210098,China [3]Key Laboratory of Reservoir and Dam Safety of the Ministry of Water Resources,Nanjing 210029,China

出　　处：《Journal of Mountain Science》2024年第6期1868-1885,共18页山地科学学报（英文）

基　　金：financially supported by the National Natural Science Foundation of China(Grant Nos.U22A20602,U2040221).

摘　　要：A cascading failure of landslide dams caused by strong earthquakes or torrential rains in mountainous river valleys can pose great threats to people’s lives,properties,and infrastructures.In this study,based on the three-dimensional Reynoldsaveraged Navier-Stokes equations(RANS),the renormalization group(RNG)k-εturbulence model,suspended and bed load transport equations,and the instability discriminant formula of dam breach side slope,and the explicit finite volume method(FVM),a detailed numerical simulation model for calculating the hydro-morphodynamic characteristics of cascading dam breach process has been developed.The developed numerical model can simulate the breach hydrograph and the dam breach morphology evolution during the cascading failure process of landslide dams.A model test of the breaches of two cascading landslide dams has been used as the validation case.The comparison of the calculated and measured results indicates that the breach hydrograph and the breach morphology evolution process of the upstream and downstream dams are generally consistent with each other,and the relative errors of the key breaching parameters,i.e.,the peak breach flow and the time to peak of each dam,are less than±5%.Further,the comparison of the breach hydrographs of the upstream and downstream dams shows that there is an amplification effect of the breach flood on the cascading landslide dam failures.Three key parameters,i.e.,the distance between the upstream and the downstream dams,the river channel slope,and the downstream dam height,have been used to study the flood amplification effect.The parameter sensitivity analyses show that the peak breach flow at the downstream dam decreases with increasing distance between the upstream and the downstream dams,and the downstream dam height.Further,the peak breach flow at the downstream dam first increases and then decreases with steepening of the river channel slope.When the flood caused by the upstream dam failure flows to the downstream dam,it can produce a surge wave

关 键 词：Cascading landslide dams Cascading dam failure process Detailed numerical simulation model Flood amplification effect Parameter sensitivity analyses 

分 类 号：P642.22[天文地球—工程地质学] TV698.237[天文地球—地质矿产勘探]