三峡库区巴东县城附近主要滑坡边界轨迹分形分维特征与滑坡稳定性关系  

A Study of the Relationship between Landslide Stability and Fractal Dimension of the Major Landslide Trace Pattern near Badong in the Reservoir Region of the Yangtze Gorge Project

作　　者：吴树仁[1] 韩金良[1] 石菊松[1] 张永双[1] 何锋[1] 董诚[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081

出　　处：《地球学报》2005年第5期455-460,共6页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:40472153;40272130);科技部公益基础项目(编号:2004DIB3J080;2001DIA20027)资助。

摘　　要：为了探索复杂滑坡轨迹结构演化及其稳定性定量分析计算的新途径,本文利用分形分维理论,分析三峡库区巴东县城附近滑坡边界轨迹的几何分形结构,并采用盒维数法分别求得巴东县城附近11个滑坡边界轨迹的分维值,计算结果表明:每个滑坡的轨迹结构具有其特征性的分维值,轨迹结构越复杂,结构层次越清楚,分维值越高;其中,榨房坪滑坡和黄腊石滑坡的分维值最高,分别为1.50和1.483,西壤口和谭家湾滑坡的分维值最低,分别为0.925和0.732;而黄土坡和赵树岭滑坡的分维值介于二者之间,分别为1.111和1.091.结合典型滑坡边界轨迹结构演化与滑坡稳定性关系的定性分析及前期滑坡稳定性定量计算和模拟分析,初步揭示:滑坡边界轨迹结构与稳定性是密切相关的,滑坡边界轨迹宏观扩展增值越明显,轨迹结构越复杂,分维值越高,其稳定性条件也越差,因此,分数维可作为衡量滑坡轨迹结构复杂性和稳定性的重要标志;滑坡边界轨迹宏观扩展变形存在一个极限,超过这个极限滑坡的局部失稳就转化为整体滑动;而滑坡边界轨迹则记录了滑坡变形扩展现象和信息,因此,相对应地滑坡轨迹分形结构的分维值也应存在一个极值,在极值点滑坡体处于临滑状态;滑坡边界轨迹结构的极限分维值大致为1.4～1.5,此时滑坡接近于整体极限失稳状态,而分维值在1.1～1.3之间则表示滑坡处于整体稳定,局部存在潜在失稳状态,分维值小于1则表示滑坡处于相对稳定状态.In order to find out a new approach to the quantitative analysis of the evolution and stability of the complex landslide boundary trace pattern, this paper employed the fractal theory to analyze the geometrical fractal pattern of the landslide boundary trace patterns near Badong county seat in the reservoir region of the Three Gorge project on the Yangtze River. In addition, the box dimension method was used to obtain the fractal values for the boundary trace pattern of 11 landslides near Badong county seat. The computation results show that the trace pattern of each landslide is characterized by its characteristic fractal value. The more complex the trace pattern, the clearer the structure layers, and the higher the fractal value. Of them, two with higher fractal values are respectively Zhafangping landslide of D = 1.50 and Huanglashi landslide of D = 1. 483, and two with lower fractal values are respectively Xirangkou landslide of D = 0. 925 and Tangjiawan landslide of D = 0. 732. The fractal values of Huangtupo landslide and Zhaoshuling landslide are in between, being respectively D = 1.111 and D = 1.091. The relationship between the evolvement of the boundary trace pattern and the stability of representative landslide was analyzed, and the prophase information of quantitative and simulative calculation for the landslide stability was used in the area. The study has yielded some important conclusions. The relation between the landslide boundary trace pattern and landslide stability is intimate, and the clearer the macro-extension deformation of the landslide trace patterns, the more complex the landslide trace patterns, the higher the fractal value, and the poorer the stability of the corresponding landslide. Therefore, the fractal dimension may serve as a statistical assessment criterion for the analysis of the complexity and stability of the landslide boundary trace pattern. There is a critical limit of macro-extension deformation of the landslide boundary trace pattern, and local deformation of the landslid

关 键 词：滑坡轨迹结构 分形分维 滑坡稳定性 巴东县城 黄腊石滑坡 分形结构 定性关系 三峡库区 边界 分维特征 

分 类 号：P642.22[天文地球—工程地质学] O484.1[天文地球—地质矿产勘探]