摘要
2003年7月13日,位于长江支流青干河左岸的秭归县千将坪村发生巨型基岩滑坡。滑坡体总体积约2.04×107 m3。因千将坪滑坡位于三峡库区,且是在三峡水库首次蓄水至135 m水位后不到2周时间内发生的,其滑坡体地质特征以及成因机制受到社会各界关注。在对千将坪滑坡特征、基本地质条件与力学参数进行调查和研究基础上,利用非连续变形分析方法兼有真实时间模拟和非连续大变形问题分析于一体的优势,研究用非连续变形分析数值模型反映滑坡启动的识别方法,并对该滑坡体的启动条件和滑坡全过程特征进行数值模拟。分析结果表明,千将坪滑坡启动的原因主要是降雨以及库水位上升使得滑坡体控制性滑面力学参数降低所致;滑坡类型为由上部变形错动引起的推移式滑坡;由非连续变形分析方法模拟得到的滑坡最大滑移速度及上部最大滑动错距与实际情况具有可比性,由数值模拟得出的滑坡滑动持续时间约40 s。另外,提出的研究思路与方法可为其他滑坡机制研究所借鉴。
On July 13, 2003, a foundation rock landslide with total volume of about 2.04×10^7m^3 happened in Qianjiangping on the left bank of Qinggan River in Zigui County located in the Three Gorges Reservoir area. Intensive attention has been aroused for the geologic features and startup mechanism of the landslide because it located in the Three Gorges Reservoir area and happened in the time no more than 2 weeks after the storage of the Three Gorges Reservoir up to 135 m elevation. On the basis of field investigation on the general geological conditions and its mechanical parameters of the actual landslide, and with advantages of real time variable employment and large discontinuous deformation simulation in the method of discontinuous deformation analysis（DDA）, the startup criterion for a landslide using DDA numerical modeling has been studied; and the numerical simulation of the startup and whole failure process of the landslide has been carded out by use of DDA method. It is shown that the main reason of Qianjiangping landslide is the reduction of mechanical parameters of controlled sliding surfaces in the landslide body resulted from rainfall and rise of reservoir water level. The landslide belongs to thrust load caused landslide. Compared to the actual process characteristics of the Qiangjiangping landslide, the maximum landslide velocity, and the maximum slide distance are quite reasonable and acceptable. The total duration of the landslide obtained by DDA modelling is about 40 s. In addition, the methods adopted in this paper supply a new approach for stability study of landslide or other geotechnical engineering.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2006年第7期1297-1303,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金重点项目(50539110)
水利部科技创新项目(SCX2003–21)
水利部"948"计划技术创新与转化项目(CT200334)
关键词
边坡工程
非连续变形分析
数值模拟
千将坪滑坡
滑坡启动
滑坡全过程
推移式滑坡
slope engineering
discontinuous deformation analysis（DDA）
numerical simulation
Qianjiangping landslide
startup of landslide
whole failure process of landslide
thrust load caused landslide
