高速远程滑坡沿程速度演化与冲击力分布研究——以三溪村滑坡为例  

Velocity evolution and impact force distribution of high-velocity and long-runout landslide debris flow along the way:A case study of Sanxi Village landslide

作　　者：陈果 钮志林 樊晓一[1,3] 胡晓波 CHEN Guo;NIU Zhilin;FAN Xiaoyi;HU Xiaobo(School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang 621010,China;China Highway Engineering Consultants Corporation,Beijing 100089,China;School of Civil Engineering and Geomatics,Southwest Petroleum University,Chengdu 610500,China;Institute of Mountain Hazards and Environment,CAS,Chengdu 610041,China)

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]中国公路工程咨询集团有限公司,北京100089 [3]西南石油大学土木工程与测绘学院,四川成都610500 [4]中国科学院、水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《自然灾害学报》2022年第3期232-241,共10页Journal of Natural Disasters

基　　金：国家自然科学基金项目(41877524,41971214)。

摘　　要：滑坡的运动速度是研究其致灾机制的关键因素,滑坡对建筑物的冲击力是评判其致灾强度的重要指标。对于灾难性高位远程滑坡而言,速度和冲击力是导致建筑损坏和人员伤亡的关键因素,由于灾难性滑坡的突发性、隐蔽性,以及目前现场监测技术的局限性,对其运动速度和冲击力的实时监测存在较大的难度。本文以三溪村为例,利用三维离散元软件PFC,结合无侧限单轴压缩试验进行参数标定,模拟三溪村滑坡启动、下滑、堆积和冲击山区房屋的整个过程。研究结果表明:(1)受地形影响,前缘右侧、中部、左侧岩土体峰值速度存在差异,中部岩土体呈现最大的峰值速度;(2)前缘右侧岩土体滑坡初始阶段呈现最大的加速度,前缘左侧岩土体减速阶段呈现最大的加速度;(3)滑坡冲击力时程关系呈现为单峰特征,冲击过程可划分为动态冲击阶段和准静态堆积阶段,且峰值冲击力与房屋距滑源区距离成反比。在三溪村滑坡的堆积阶段,山区房屋主要承受滑坡岩土体的静态堆积作用。建立的冲击力-时程演化关系、峰值冲击力-运程分布关系和峰值冲击力-速度的关系,可为山区建筑防灾减灾治理工程提供参考。The velocity of landslide debris flow is a key factor in studying its mechanism that causes disasters,and the impact force of landslide debris flow on buildings is an important index in evaluating its intensity.In terms of catastrophically high velocities and long-runout landslides,velocity and impact force are key causes of damage to buildings and human casualties.Due to the sudden and hidden debris flow of catastrophic landslides and the limitations with current field monitoring technology,it is difficult to monitor the velocity and impact force of landslide debris flow in real time.In this paper,Sanxi Village was taken for a case study,and PFC^(3D) was used in combination with an unconfined uniaxial compression test for parameter calibration to simulate the entire process of landslide initiation,sliding,accumulation,and impact on houses in mountainous areas in Sanxi Village.The main findings of this paper are:(1)Under the influence of topography,there were differences in the peak velocity of the rock mass on the right,middle,and left side of the leading edge,with the highest peak velocity observed in the middle of the rock mass;(2)The rock mass on the right side of the leading edge presented the maximum acceleration in the initial stage of the landslide,while the rock mass on the left side presented the maximum acceleration in the deceleration stage;(3)The time-history curve of the debris flow impact force showed the single-peak characteristics.The impact force can be divided into a dynamic impact stage and a quasi-static accumulation stage.The peak impact force was inversely proportional to the distance between the building and the sliding source area.In the accumulation stage of landslide debris flow,houses in mountainous areas were mainly exposed to static accumulation of landslide debris flow.The relationship between impact force time history evolution,peak impact capacity transport distribution,and peak impact speed can provide reference for the disaster prevention and mitigation project in mountainous ar

关 键 词：离散元颗粒流 高速远程滑坡 山区建筑 前缘速度 冲击力 

分 类 号：P642.22[天文地球—工程地质学] X43[天文地球—地质矿产勘探]