滑坡地下渗流流速的光纤光栅监测装置研发  

Research and Development of Landslide Seepage Monitoring Device Based on Fiber Bragg Grating

作　　者：杨坤 徐卫亚[3] 孟永东[1,2] 张伟杰 沐清云 蔡征龙[1,2] YANG Kun;XU Weiya;MENG Yongdong;ZHANG Weijie;MU Qingyun;CAI Zhenglong(National Field Observation and Research Station of Landslides in Three Gorges of Yangtze River,China Three Gorges University,Yichang 443002,China;College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China;Geotechnical Research Institute,Hohai University,Nanjing 210098,China)

机构地区：[1]三峡大学湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002 [2]三峡大学水利与环境学院,湖北宜昌443002 [3]河海大学岩土工程科学研究所,南京210098

出　　处：《三峡大学学报（自然科学版）》2024年第2期1-7,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金重点项目(51939004)。

摘　　要：地下渗流是影响滑坡稳定性的重要因素之一,实现渗流相关物理指标的实时有效监测是准确分析滑坡地下水响应规律和滑坡演化过程的关键.常规渗流监测装置无法兼具渗流速率和流向两个关键参数,且存在抗干扰能力弱、监测成本高、精度低的局限性.结合主动加热光纤光栅法的温度传感特性和地下渗流场中的热对流规律,研发滑坡体渗流速率和流向的光纤光栅监测装置,建立基于测孔温度光纤光栅示踪的渗流监测系统.通过开展模型试验对监测装置和监测系统的有效性进行验证,研究结果表明:通过对测孔各方位光纤光栅的温度特征值变化率kη实施监测,可准确识别地下渗流的流速和流向;在流速量程1.2×10^(-4)~3.0×10^(-4)m/s范围内,装置对渗流速率具有较好的线性度和监测能力,装置监测渗流速率的误差占比11.2%,渗流流向的识别精度为11°左右.该装置的研发为库岸滑坡体地下渗流的精细监测提供了一种新的方法和技术手段.Underground seepage is one of the important factors affecting the stability of landslides.Real time and effective monitoring of physical indicators related to seepage is the key to accurately analyzing the response law of landslide groundwater and the evolution process of landslides.Conventional seepage monitoring devices cannot simultaneously possess two key parameters:seepage rate and flow direction,and have limitations such as weak anti-interference ability,high monitoring cost,and low accuracy.Based on the temperature sensing characteristics of the active heating fiber optic grating method and the thermal convection law in the underground seepage field,a fiber optic grating monitoring device for landslide seepage flow velocity and direction is developed,and a seepage monitoring system based on measuring hole temperature fiber optic grating tracking is established.The effectiveness of the monitoring device and monitoring system was verified through model experiments,and the research results showed that measuring the temperature characteristic value change rate kηof the fiber Bragg grating in each direction,can accurately identify the flow velocity and direction of underground seepage.Within the flow velocity range of 1.2×10^(-4)m/s to 3.0×10^(-4)m/s,the device has good linearity and monitoring ability for seepage velocity.The error of monitoring seepage velocity by the device accounts for 11.2%,and the recognition accuracy of seepage flow direction is about 11°.The development of this device provides a new method and technical means for precise monitoring of underground seepage in landslide bodies on the reservoir bank.

关 键 词：滑坡 渗流监测 光纤布拉格光栅 主动加热光纤法 牛顿冷却定律 

分 类 号：TU43[建筑科学—岩土工程]