地铁基坑变形的多标度特性分析及变形趋势研究  

Multi-scale characteristics analysis and trend study of subway foundation pit deformation

作　　者：林伟[1] 薛晓辉[1] 李常茂[1] 李新征 LIN Wei;XUE Xiaohui;LI Changmao;LI Xinzheng(Shaanxi Railway Institute,Weinan 714000,China;Jinan Railway Engineering Co.,Ltd.of China Railway 10th Group,Jinan 250001,China)

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000 [2]中铁十局集团济南铁路工程有限公司,山东济南250001

出　　处：《武汉大学学报（工学版）》2021年第4期332-338,共7页Engineering Journal of Wuhan University

摘　　要：为准确掌握基坑变形发展趋势,以多重分形去趋势波动分析(multifractal detrended fluctuation analysis,MFDFA)及Spearman秩次检验为基础,构建了基坑变形趋势的综合判断模型。先利用MF-DFA评价基坑累计变形序列的多标度特性及其发展趋势,再利用Spearman秩次检验对基坑速率序列进行变形趋势评价,以实现变形趋势判断的补充和佐证;同时,为掌握基坑变形序列在不同阶段的多标度特性及变形趋势,将分析过程划分为整体评价分析和分阶段评价分析。实例检验表明:基坑不同监测点的变形序列在不同分析阶段的h(q)值与q值均不具独立关系,各监测点的变形过程均具多标度特性及多重分形特征,且各监测点的累计变形将会进一步增加,但趋势性均较小;通过Spearman秩次检验,得出各监测点的速率序列均呈下降趋势,检验结果与MF-DFA一致,验证了2种方法在基坑变形趋势分析中的适用性和有效性,为基坑变形规律研究提供了一种新的思路。In order to accurately grasp the development trend of deformation of foundation pit,the comprehen-sive judgment model of deformation trend of foundation pit is built on the basis of multifractal detrended fluctua-tion analysis(MF-DFA)and Spearman rank test.First,the MF-DFA method is used to evaluate the multiscale characteristic and the development trend of the cumulative deformation sequence of foundation pit.Then,Spearman rank test is used to evaluate the deformation trend of the foundation pit rate sequence,to complement and verify the deformation trend judgment.To master the multi-scale characteristics and deformation trend of the deformation sequence of the foundation pit at different stages,the analysis process is divided into overall evaluation analysis and phased evaluation analysis.The case test shows that there is no independent relationship between the values of h(q)and q of deformation sequence of different monitoring points in the foundation pit at different analysis stages.It is concluded that the deformation process of each monitoring point has multi-scale and multifractal characteristics,and the cumulative deformation of each monitoring point will be further in-creased,but the trend is smaller.Spearman rank test results show that the rate sequence of each monito-ring point is declining,and the results of the test are in agreement with the results of MF-DFA.The applicability and effectiveness of the two methods in the analysis of the deformation trend of the foundation pit are verified,which provides a new idea for the study of the deformation law of the foundation pit.

关 键 词：地铁基坑 多重分形去趋势波动分析 Spearman秩次检验 多标度特性 变形趋势判断 

分 类 号：TU473[建筑科学—结构工程]