传统的时间序列法是对土石坝变形观测量在特定时间范围内的变化特征进行拟合建模,无法揭示观测点变形测值之间的共性。采用分形理论中非线性振荡分析方法,研究了变形时间序列数据的相关性及后续建模选取数据的有效性,提出的定标指数可用来甄别监测点时间序列的位移值是否存在长期记忆性,有效的预测未来的发展趋势,并指出后续建模选取时间序列的起始范围。实例应用结果表明提出的方法可较好的分析土石坝变形性态及预测预报,为土石坝变形安全分析提供了一种新途径。
The traditional time series analysis method adopted to fit the earth and rockfill dam deformation observation data can't reveal the commonness between deformation observation points. In this paper,fractal theory and detrended fluctuation analysis were combined to analyze time series autocorrelation and the effectiveness to select data continual modeling of earth-rock dam. Then the calibrated index was introduced to describe the dynamic characteristics of deformation data series and forecast the trend of development. Finally,scaling index was proposed to distinguish whether the displacement value of monitoring data sequence "long-term memory"of existence and the future trend of the development of the monitoring points. The proposed method in this paper can provide a better way to analyze earth-rock dam deformation in very complicated state and predict the possible development of survey points in future,which provides a new way to solve various nonlinear problems of earth-rock dam safety analysis in deformation.