崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链演化特征分析及防治对策研究  

Analysis on Disaster Chain Evolution Characteristics of the Collapse of Landslide-Barrier Lake-Dam Flood-Debris Flow and Study on Prevention and Control Countermeasures

作　　者：田士军[1] TIAN Shijun(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道标准设计》2024年第2期15-23,共9页Railway Standard Design

基　　金：中国国家铁路集团有限公司科技研究开发计划项目(P2021G047)。

摘　　要：某沟谷两岸坡面陡峻,沟谷狭窄,纵坡降较大,在地震、降雨等不利因素影响下,其左岸堆积体上方的崩滑堵沟隐患点可能出现失稳,并发展为崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链。针对此灾害链不同阶段的演化特征,采用相应的数值模拟模型和数值计算方法进行模拟分析和计算,评价其对沟口桥梁工程的影响,并采取相应的防治对策。经分析计算,崩塌滑坡隐患点距沟底高程落差约1 km,岩体体积约8×10^(6)m^(3),平均厚度约26 m,崩塌滑坡堵河可形成最大水深为14.4 m、面积约为7.19×10^(4)m^(2)、方量约为2.74×10^(5)m^(3)的堰塞湖;堰塞湖溃决形成洪水过程中,桥梁处最大水深为4.43 m(不含原始水位),最大流速为7.54 m/s,峰值流量为807 m^(3)/s;在溃决洪水强烈揭底冲刷和侵蚀的条件下,溃决洪水引发的泥石流在桥梁处的最大水深为7.1 m、最大流速为8 m/s、峰值流量为1685.5 m^(3)/s、最大冲刷深度为16.58 m。为减少该灾害链对桥梁工程的影响,采取河道疏通、岸坡防护和监测预警等防治措施。The slope on both sides of a gully is steep with narrow valleys and large longitudinal slopes.Under the influence of earthquake,rainfall and other adverse factors,the hidden danger point of landslide and gully blocking above the left bank accumulation body may appear instability,and develop into a disaster chain of collapse,landslide-barrier lake-outburst flood-debris flow.In view of the evolution characteristics of the disaster chain in different stages,the corresponding numerical simulation model and numerical calculation method are used to simulate and calculate the impact of the disaster chain on a bridge,and the corresponding prevention and control countermeasures are taken.Through analysis and calculation,the height drop between the potential point of collapse and landslide and the ditch bottom is about 1 km,the volume of the rock mass is about 8×10^(6) m^(3),the average thickness is about 26 m,the biggest water depth of barrier lake formed by landslides blocking rivers is 14.4 m,the area is about 7.19×10^(4) m^(2) and the square volume is about 2.74×10^(5) m^(3);In the process of forming flood from barrier lake outburst,the maximum water depth at the bridge is 4.43 m(excluding the original water level),the maximum flow rate is 7.54 m/s,and the peak flow is 807 m^(3)/s;Under the condition of intense bottom erosion and the erosion caused by outburst flood,the maximum depth at the bridge of debris flow caused by outburst flood is 7.1 m,the maximum velocity is 8 m/s,the peak flow is 1685.5 m^(3)/s,and the maximum scour depth is 16.58 m.In order to reduce the impact of the disaster chain on bridge engineering,prevention and control measures such as river dredging,bank slope protection,monitoring and early warning are taken.

关 键 词：崩塌滑坡 堰塞湖 溃决洪水 泥石流 灾害链 堵沟 岸坡防护 监测预警 

分 类 号：P642.2[天文地球—工程地质学] U212.22[天文地球—地质矿产勘探]