北京通州某地浅部松散层压缩变形BOTDR监测分析

BOTDR Monitoring Analysis of Loose Layer Deformation Compression of a Shallow Area in Tongzhou,Beijing

松散层的压缩变形是引起地面沉降的主要因素,当变形量过大时会引起一系列地质灾害。为了对北京通州某地区松散层压缩变形进行精细化观测,应用直埋金属基索状应变感测光缆的方法对北京通州某地112 m松散层压缩变形进行了一年半的监测。监测结果表明:监测期间,监测地区松散层主要压缩层位为5~30 m,该层位压缩量随着时间的推移和深度的加深有变小的趋势。通过分析认为,该地区松散层压缩变形主要是由于地下水水位的变化、施工附加载荷及本身岩性特点等引起的。BOTDR技术可以精准地获取松散层的变形信息,是一种监测松散层压缩量的有效手段。

The compression deformation of the loose layer is the main factor causing the land subsidence,and large deformation will cause a series of geological disasters.In order to carry out fine observation on the compression deformation of loose layer in Tongzhou,Beijing,112 m thick loose layer has been monitored for one and a half years by using directly buried cable.The results show that during the monitoring period,the main compressed layer of the loose layer in the monitoring area is 5~30 m.The amount of compression in this layer tends to decrease with time,and also decrease with depth.Based on the analysis,the main causes of the compression deformation of the loose layer in this area are the change of groundwater level,the additional load of construction and the characteristics of its own lithology.BOTDR technology can accurately obtain the deformation information of loose layer,and it is an effective means to monitor the compression of loose layer.