废弃采空区残余沉降时变特征的多尺度分析

Multi Dimension Analysis on Time-Variation Features of Residual Subsidence in Abandoned Goaf

为了揭示废弃采空区复杂的多层次结构,采用小波分析方法,选择Morlet小波函数,对废弃采空区残余沉降时间序列作连续小波变换,计算小波功率谱,并以红噪声为背景进行显著性检验,然后将同一采空区不同测点的分析结果作对比分析。综合分析结果表明:废弃采空区残余沉降具有明显的周期性,各变化周期表现出一定的阶段性,高频周期持续时间相对较短;同一采空区中,不同测点有相等或近似相等的显著变化周期和持续时间。小波功率谱直观地表达了废弃采空区残余沉降的时空演变过程,能对废弃采空区建筑地基稳定性进行评价。

In order to reveal the complicated multi layer structures of the abandoned goaf,the wavelet analysis method was applied to select the Morlet wavelet function for the continued wavelet conversion of the residual subsidence time sequence in the abandoned goaf and for the wavelet energy calculation.Based on the red noise as the background,the remarkability inspection was conducted and then the analysis results at the different measuring points in the same goaf area were compared and analyzed.The comprehensive analysis results showed that the residual subsidence in the abandoned goaf would have an obvious periodicity,each varied period would have a certain stage and the sustained time of the high frequency would be relative short.In the same goaf,there would be an equivalent or approximate equivalent obvious variation period and sustained time.The wavelet power spectrum could directly express the time space evolution process of the residual subsidence in the abandoned goaf which could provide the reliable references to the stability evaluation of the building foundation above the abandoned goaf.