【摘要】 地面沉降作为目前长三角地区危害最严重的地质灾害,对长三角地区的经济发展造成了十分严重的危害.采用布里渊光时域反射技术(Brillouin Optical Time Domain Reflectometer,BOTDR)及准分布布拉格光纤光栅(Fiber Bragg Grating,FBG)等分布式监测技术(Distributed Fiber Optic Sensing,DFOS),利用连云港市徐圩新区污水处理厂内一个130m的钻孔,通过分布式光缆对该地第四纪地层的地面沉降进行了为期两年的监测与分析.主要的结果如下:目前该地区的主要沉降层为第一弱透水层;地层的沉降量与抽水含水层的孔隙水压力变化一致,且存在一定的滞后性;徐圩地区地面沉降的主要原因是与抽水含水层相邻的弱透水层的释水压缩,而不是抽水含水层的压缩变形;DFOS技术为进一步研究地面沉降的机理与变形特点提供了一种较为准确的监测方法.更多还原

【Abstract】 As the most serious geological hazard in the Yangtze River Delta area,land subsidence has caused serious damage to the economic development of the Yangtze River Delta area.In this paper,the Quaternary land subsidence is long-term monitored by the Distributed Fiber Optic Sensing(DFOS)technology.The optical fibers based on the BOTDR(Brillouin Optical Time Domain Reflectometer)technology and the fiber grating sensors based on the FBG(Fiber Bragg Grating)technology are laid in a 130 mborehole drilled in Xuwei,Lianyungang city.The monitoring data collected in two years is analyzed.The main compaction occurs at the first aquitard.The deformation of stratum is consistent with the variation of pore water pressure of pumping aquifer.And there is a hysteresis between them.The main cause of ground subsidence in Xuwei is the compression of the aquitard adjacent to the pumping aquiferrather than the deformation of the pumping aquifer.DFOS technology provides a very advanced monitoring method for the study of the mechanism and deformation characteristics of ground subsidence.更多还原