南水北调前后京津城际铁路北京段地面沉降演化特征

Evolution Characteristics of Land Subsidence in Beijing Section of Beijing-Tianjin Intercity Railway Before and After the South-to-North Water Diversion Project

    摘要
  • 摘要: 京津城际铁路北京段全长50 km，铁路线穿越北京东八里庄-大郊亭沉降区，沿线不均匀沉降给高速铁路的安全运行带来一定威胁。南水北调工程给北京带来了新的水源，平原区地下水开采减少，地面沉降发展态势有所减缓。以京津城际铁路北京段为研究区，选取雷达卫星二号(Radarsat-2)（2011—2015年）与哨兵一号（Sentinel-1）（2016—2019年）卫星影像，采用永久散射体干涉测量（permanent scatterer interferometric synthetic aperture radar, PS-InSAR）技术获取铁路沿线及其附近区域的时序沉降信息。重点分析了研究区南水北调前后铁路沿线沉降演化的差异性。在此基础上，结合铁路沿线地质资料和地下水动态监测数据，分析可压缩层厚度差异、地下水位变化与地面沉降的响应关系。结果表明：南水北调前（2011—2014年）铁路沿线年沉降量大于30 mm区域长度的均值为13.25 km，占北京段全长约26.50%，南水北调后（2015—2019年）已减少至8.87 km左右，占北京段全长约17.74%；同样地，铁路沿线年沉降极值的均值由105 mm减小至78 mm，极值位置有明显东移，由DK17处右移至DK20附近。铁路沿线的沉降与区域沉降漏斗的发展趋势较为一致，主要受地下水长期超量开采带来的地下水位下降和可压缩层厚度影响。京津城际铁路的正常运行与铁路沿线沉降之间未见明显相互影响。

     

    Abstract:
    Objectives The Beijing section of Beijing-Tianjin Intercity Railway is 50 km long. The railway line crosses the subsidence area from Dongbalizhuang to Dajiaoting in Beijing. The uneven subsidence along the line poses a certain threat to the safe operation of high-speed railway. The South-to-North Water Diversion Project has brought new water sources to Beijing, the exploitation of groundwater in the plain area has decreased, and the development trend of land subsidence has slowed down.
    Methods Taking the Beijing section of Beijing-Tianjin Intercity Railway as the research area, we select Radarsat-2(2011—2015) and Sentinel-1(2016—2019)satellite images, and use permanent scatterer InSAR (PS-InSAR) technology to obtain the time-series subsidence information along and near the railway. The difference of subsidence evolution along the railway before and after the South-to-North Water Diversion in the study area is analyzed. On this basis, combined with the geological data and groundwater dynamic monitoring data along the railway, the response relationship between compressible layer thickness difference, groundwater level change and land subsidence is analyzed.
    Results Before the South-to-North Water Diversion (2011—2014), the average length of the area with annual subsidence greater than 30 mm along the railway is 13.25 km, accounting for about 26.50% of the total length of Beijing section. After the South-to-North Water Diversion (2015—2019), it has been reduced to about 8.87 km, accounting for about 17.74% of the total length of Beijing section. Similarly, the mean value of the annual subsidence extreme value along the railway decreases from 105 mm to 78 mm, and the extreme value position moves eastward obviously from DK17 to near DK20.
    Conclusions The subsidence along the railway is consistent with the development trend of regional subsidence funnel, which is mainly affected by the decline of groundwater level caused by long-term over exploitation of groundwater and the thickness of compressible layer. After the South-to-North Water Diversion Project, the subsidence along the railway has slowed down significantly. There is no obvious interaction between the normal operation of Beijing-Tianjin Intercity Railway and the subsidence along the railway.

     

    • HTML全文
    • 参考文献(19)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回