贵州水城“7.23”高位远程滑坡冲击铲刮效应分析

Impact and scraping effects of the high-elevation,long-runout"7.23"landslide in Shuicheng,Guizhou

以2019年贵州水城“7.23”滑坡为例,采用现场调查、无人机航测和数值模拟技术,分析了滑坡的运动过程和冲击铲刮特征,结果表明:(1)水城“7.23”滑坡属典型的高位远程滑坡,滑体高位启动后冲击下方凸起山脊,铲刮地表残坡积土层,并解体形成碎屑流,最大铲刮深度可达11 m;(2)模拟结果显示,滑坡运动最大速度为30 m∙s^-1,最大动能达8900 kJ,铲刮体积达46×10^4 m^3,最终体积为116×10^4 m^3,灾害放大效应明显;(3)水城滑坡的冲击铲刮过程可分为冲击嵌入→剪切推覆→裹挟混合三个阶段。

This paper analyzes the Shuicheng"7.23"landslide in Guizhou,2019.Based on the field survey,Un⁃manned Aerial Vehicle(UAV)images and numerical simulation,the movement process,and impact and scraping ef⁃fects of this landslide are characterized.Results suggest that,(1)the Shuicheng"7.23"landslide sliding volume is about 70×10^4 m^3,with the horizontal slide distance 1,360 m,elevation difference 430 m between the front and the toe,and the equivalent friction angle 19°,implying a typical high-level,long-distance slope slide;(2)After the initiation of the slide,it hit the convex ridge,scraped the residual slope soil of the surface,disintegrated and formed a debris flow,resulting in a maximum scraping depth of 11 m;(3)The numerical simulation shows that the maximum velocity of the landslide is 30 m∙s^-1,the maximum kinetic energy is 8,900 kJ,the scrap volume is 46×10^4 m^3,and the deposit volume is 116×10^4 m^3,with an obvious amplifying effect of hazard;(4)The impact and scraping process of the Shuicheng land⁃slide can be divided into 3 stages,impact insertion,shear nappe and mixed accumulation of sliding debris.