基于WFBG技术的崩岸场地变形和渗流特征研究——以扬中指南村为例  

Deformation and seepage characteristics of the bank collapse site based on WFBG technology——a case study of Zhinan Village,Yangzhong

作　　者：梅世嘉 姜月华[1,2] 杨海 周权平 陈孜[1,2] 贾正阳 金阳 张鸿 张博[3] MEI Shijia;JIANG Yuehua;YANG Hai;ZHOU Quanping;CHEN Zi;JIA Zhengyang;JIN Yang;ZHANG Hong;ZHANG Bo(Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China;Key Laboratory of Watershed Eco-Geological Processes,Ministry of Natural Resources,Nanjing 210016,Jiangsu,China;Nanjing University,Nanjing 210023,Jiangsu,China)

机构地区：[1]中国地质调查局南京地质调查中心,江苏南京210016 [2]自然资源部流域生态地质过程重点实验室,江苏南京210016 [3]南京大学,江苏南京210023

出　　处：《华东地质》2024年第2期228-239,共12页East China Geology

基　　金：国家重点研发计划“岩溶发育特征的快速探测与精细刻画技术和装备研发(编号:2022YFC3705001)”;中国地质调查局“长江经济带暨长三角一体化发展区资源环境承载能力监测评价(编号:DD20221728)”项目联合资助。

摘　　要：崩岸灾害对长江岸线城镇和重大基础设施安全构成严重威胁,目前常用的监测技术存在参数受限、监测频率低等问题。为了提升崩岸灾害的监测和预警效果,文章引入了基于弱光栅(WFBG)技术的实时监测方法。该方法利用弱光栅串传感器作为测量单元,采用时分/波分混合复用解调技术和换算公式,通过主动施加热源以区分地下水流速的大小,实现了崩岸场地内应变、温度、位移、流速等多个参数的实时监测。在扬中市指南村崩岸场地实验中,WD02孔的监测数据反映20~30 m和62~80 m深度存在两个流速异常区域,流速分别达2.98×10^(-6) m/s和3.4×10^(-6) m/s,较上下相邻地层高出近1倍。因此,应密切关注这两个异常区域的地层。实践表明,该技术具有定位准确、数据丰富和实时监测的优势,能够克服极端天气条件下的挑战,可为崩岸灾害的监测预警提供一种先进可靠的手段。The riverbank collapse poses a serious threat to the safety of urban areas and critical infrastructures along the Yangtze River.At present,the commonly used monitoring techniques expose some problems,such as limited parameters and low monitoring frequency.To improve the effectiveness of riverbank collapse monitoring and early warning,a real-time monitoring approach based on weak fiber Bragg grating(WFBG)technology is introduced.This method employs weak fiber brag grating sensors as measuring units,and then utilizes time-division/wavelength-division hybrid multiplexing demodulation techniques together with some relevant conversion formulas to distinguish groundwater flow velocities under active heat source.A real-time monitoring system of riverbank collapse site can be set up for collecting multiple parameters simultaneously,including strain,temperature,displacement,flow velocity,and so on.We analyzed the monitoring data of WD02 borehole,which was located at the Zhinan Village riverbank collapse site in Yangzhong City.The results showed that there were two abnormal flow velocity zones at the depth of 20~30 m and 62~80 m,where the follow velocities reached 2.98×10^(-6) m/s and 3.4×10^(-6) m/s,respectively,nearly twice of the values observed in adjacent layers.Consequently,it is necessary to pay more attention to these two abnormal zones.Typical practice case shows that this technology has the advantages of accurate positioning,abundant data collecting and real-time monitoring even under extreme weather conditions.This research provides a cutting-edge and reliable alternative solution for the monitoring and early warning of riverbank collapse disasters.

关 键 词：WFBG 温度 应变 渗流 崩岸 扬中市指南村 

分 类 号：P954[天文地球—自然地理学] P642.2