滑坡监测点运动轨迹的分形特性及其应用研究

通过对滑坡监测数据的理论分析,表明监测点位移累加值依赖于监测周期,其运动轨迹具有分形特征;同时,基于滑坡的演化过程及地表裂缝的分期配套,提出在滑坡灾变过程中,内部各点运动方向的趋势性将逐渐增强,运动分维数是一个降低的过程。根据三峡库区一复活型滑坡的宏观变形特征,判定出该滑坡处于缓慢变形阶段;利用计盒定理,求解该滑坡2007～2009年的地表GPS监测点运动轨迹曲线的分维数,其值均接近于1,反映出滑坡运动方向趋势性较强,滑坡变形对主控因素的响应较敏感,该结论与滑坡的实际变形特征吻合。监测点运动轨迹的分形理论对滑坡监测数据的有效利用、滑坡演化阶段的判断及变形趋势的预测具有一定的理论与指导意义。

FRACTAL CHARACTERISTICS OF LANDSLIDE MONITORING POINT MOVEMENT TRACE AND ITS APPLICATION

Through analyzing the monitoring data of the landslide,it indicates that the monitoring point s accumulation displacement amounts depended on the monitoring periods,which reflects the characteristics of fractal.At the same time,based on the landslide fissures development process,the motion directions of the landslide internal points are getting uniform,and the motion fractal dimension number reduced.Taking a landslide in Three-Gorge area for example,this landslide is creeping with a constant velocity according to the analysis of the macroscopic deformations.Meanwhile,the fractal dimension numbers of the GPS monitoring points motion trajectory curves are calculated by the box-counting law from 2007 to 2009 year,and the results are all close to 1.The results indicate that the motion directions of the monitoring points become uniform;and the dominant controlling factor plays an important role in the landslide deformation;it is consistent with the reality deformation features.Therefore,the fractal theory applying to the monitoring point s motion trajectory analysis is an effective way to use the monitoring data to judge and predict the landslide development stage.