采用时序InSAR技术监测北京地铁网络沿线地面沉降

随着北京轨道交通的日益完善,地铁成为人们日常出行的重要交通工具,监测和治理地铁工程沿线地面沉降成为保障线性工程正常运营的一项重要基础性工作。本文基于55景覆盖北京地区的3 m高分辨率TerraSAR-X数据,采用时序InSAR分析技术获取2010年4月至2016年12月地铁网络沿线的地面沉降形变信息,系统分析了北京地铁网络沿线地面沉降时空演变规律。同时,结合Peck公式将InSAR监测结果进行建模,以7号线磁器口-广渠门内站区段为例,估算地面沉降槽的空间发展特征。研究发现：北京市地铁线路沿线表现出不同程度的形变,形变严重的路段主要集中在东部及东北部区域,最大沉降速率超过了100 mm/a;相对于其他线路,4号、10线整体情况比较稳定,14号、亦庄线次之,6号、7号线不均匀沉降最为严重;此外,地铁在不同建设时期路段表现出不同的形变特征,施工期路段较运营期沉降严重;7号线磁器口与广渠门内站间沉降槽的宽度和最大值沉降值在2010-2016年呈现增加趋势,沉降槽最大宽度约达180 m。

The Subsidence Monitoring along Beijing Subway Network Based on MT-InSAR

With the improvement of Beijing rail transportation, the subway has become an important transportation for people's daily travel. Monitoring and controlling land subsidence along metro line become an important basic work to ensure the normal operation of linear engineering. Based on 55 images of the 3m high-resolution TerraSAR-X data covering Beijing, this paper used multi-temporal InSAR analysis technology to obtain the ground settlement deformation information along the subway network from April 2010 to December 2016, and analyzed the spatial-temporal evolution of the ground settlement along the Beijing subway network. The spatial-temporal ground subsidence related to the construction of subway tunnels is usually modeled by peck formula in the space domain, which is used to calculate the ground surface settlement and determine the maximum settlement value of the settlement trough curve and the settlement trough width. Taking Ciqikou-Guangqumen station section as an example, the InSAR results were modeled by Peck formula, we estimated the spatial development characteristics of the ground subsidence trough. The results show that there are different degrees of the deformation along Beijing subway line, and the serious deformation is mainly concentrated in the eastern and northeastern regions, annual maximum subsidence rate greater than 100mm/a. Compared with other lines, the overall situation of lines 4 and 10 is relatively stable, followed by lines 14 and Yizhuang, and the uneven settlement of lines 6 and 7 is the most serious. In addition, the road sections show different deformation characteristics in different construction periods, and the settlement of the construction period is more serious than that of the operation period. The width and maximum settlement value of the settlement trough between Ciqikou and Guangqumen station (line 7) show an increasing trend from 2010 to 2016, the maximum settlement trough width reaches about 180 m.