基于分布式光纤传感技术的北京宋庄地面沉降和地裂缝综合监测

Comprehensive monitoring of land subsidence and ground fissures in Songzhuang,Beijing,based on distributed optical fiber sensing technology

针对地面沉降及地裂缝,传统点式监测技术手段难以实现地质体变形的连续监测,且无法通过地面沉降、地裂缝的综合监测定量分析两者之间的关系。基于钻孔全断面分布式光纤监测技术实现了地面沉降和地裂缝同步监测,根据监测结果对北京宋庄地区地下水-地面沉降-地裂缝之间的关系进行了分析。监测结果表明,宋庄地面沉降主要受到地下水开采影响,含水砂层抽水发生压缩变形,地裂缝两侧均存在明显的地面沉降,且差异沉降显著;差异沉降量和地裂缝变形量均持续增大,但增大速率放缓。地面沉降、地裂缝同步监测结果表明,该地区地裂缝发育主要受地层差异沉降影响。

Traditional point-based monitoring techniques are insufficient for continuous monitoring of geological deformation related to land subsidence and ground fissures.Moreover,they cannot quantitatively analyze the relationship between land subsidence and ground fissures through comprehensive monitoring.Based on distributed fiber optic monitoring technology along the full section of boreholes,simultaneous monitoring of land subsidence and ground fissures was achieved.A case analysis of the relationship between groundwater,land subsidence,and ground fissures located in the Songzhuang area of Beijing city was conducted based on the monitoring results.The results indicate that land subsidence located in Songzhuang is mainly influenced by groundwater extraction,resulting in compression deformation of the aquiferous sand layer.Significant land subsidence occurs on both sides of ground fissures,with noticeable differential subsidence.Both the amount of differential subsidence and the deformation of ground fissures continue to increase,albeit at a slower rate.Synchronous monitoring of land subsidence and ground fissures reveals that ground fissure development in the area is primarily influenced by differential subsidence of strata.