基于滑坡动力学过程的甘肃舟曲磨里滑坡风险评价  

A Dynamic Process-Based Risk Assessment of a Resurgent Landslide at Moli Village in Zhouqu County,Gansu Province,China

作　　者：王信 郭富赟 张娟 窦晓东 张毅 冯自明 WANG Xin;GUO Fuyun;ZHANG Juan;DOU Xiaodong;ZHANG Yi;FENG Ziming(Gansu Provincial Institute for Geo-Environment Monitoring,Lanzhou 730000,China;School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;First Geology and Mineral Exploration Institute,Gansu Provincial Bureau of Geology and Mineral Exploration and Development,Tianshui 741020,Gansu,China)

机构地区：[1]甘肃省地质环境监测院,兰州730000 [2]兰州大学地质科学与矿产资源学院,兰州730000 [3]甘肃省地质矿产勘查开发局第一地质矿产勘查院,甘肃天水741020

出　　处：《山地学报》2025年第1期105-121,共17页Mountain Research

基　　金：中央引导地方科技发展资金项目(23ZYQA0326)。

摘　　要：甘肃舟曲县果耶镇磨里滑坡位于青藏高原东北缘断裂构造带破碎岩土区。受区域地震及持续极端降雨耦合作用的影响,磨里滑坡于2021年发生渐进式复活变形,严重威胁果耶村、磨里村居民的生命财产安全,存在重大灾害风险。本文在现场调查、原位监测的基础上,采用连续介质力学模型模拟分析该滑坡复活变形和极端条件下失稳破坏的动力过程,并基于滑坡堆积体最大淤埋深度和最大冲击动量等典型滑坡破坏特征值,开展了极端条件下磨里滑坡灾害风险预测评价。调查发现:(1)磨里滑坡属于典型特大超深层断层破碎岩滑坡,其复活主控因素为长历时降雨入渗导致的岩体强度劣化。(2)动力过程数值模拟表明,磨里滑坡变形呈现出牵引式变形特征,极端条件下滑坡失稳破坏兼有推移式、牵引式复合变形特点:变形过程可以分为0~50 s的局部滑动阶段和50 s之后整体蠕滑变形两个阶段;滑动后0~150 s为强烈变形阶段,表现出推移式变形的特点,150 s之后为缓慢变形阶段,以牵引式变形为主。滑坡堆积体在滑动后40 s时刻将堵断滑坡前缘大水坝沟,堰塞体厚度最大可达28.3 m。(3)风险区划显示高风险区(20.4%)、中风险区(70.3%)与低风险区(9.3%)呈斑块分布,主要位于滑坡体前缘部位。本研究成果可以为磨里滑坡应急治理提供动态决策基准,也可为类似地区典型特大型滑坡风险防控提供可推广的方法框架。The landslide occuring at Moli Village in Guoye Town,Zhouqu County,Gansu Province,China is located in fractured rock-soil area of the fault belt on the northeast margin of the Qinghai-Tibet Plateau.Influenced by sustained extreme rainfall with regional earthquakes,the Moli landslide underwent progressive deformation with obvious trend of reactivation in 2021,posing a severe threat to the lives and property of residents in Moli villages and its surrounding areas.In this paper,it conducted field investigations and in-situ monitoring on the Moli landslide deformation,followed by introducing a continuum mechanics model to predict the dynamic process of the landslide's resurgent deformation,and failure in case of extreme excitation conditions.Then it evaluated its failure risk and zoning by inclusion of some key landslide failure eigenvalues in a risk model,such as the maximum burial depth and the maximum impact momentum of the landslide deposit.(1)The investigation revealed that the Moli landslide was a typical extra-large and ultra-deep landslide in fault fracture zone,with primary controlling factor for its reactivation being the deterioration of rock mass strength due to diachronic rainfall infiltration.(2)By numerical simulations of the dynamic process,it suggested that the Moli landslide generally described a retrogressive deformation pattern;however,at the critical point of failure it behaved in a way of simultaneous retrogressive and slumping motions.The deformation process can be divided into two stages:a local sliding stage from 0 to 50 seconds and an overall creep deformation stage thereafter.The period from 0 to 150 seconds after sliding represented a stage of intense deformation,characterized by slumping deformation,followed by a slow deformation stage dominated by retrogressive deformation after 150 seconds.The landslide deposit would block the Dashuiba Gully at the toe of the landslide 40 seconds after sliding,with the maximum thickness of the dammed body reaching 28.3 meters.(3)In the risk zoning,high-

关 键 词：磨里滑坡 动力过程 数值模拟 风险评估 

分 类 号：X43[环境科学与工程—灾害防治]