PPP-BOTDA分布式光纤技术在白水河滑坡监测中的应用

发布时间：2018-04-16 00:31

本文选题：边坡工程 + PPP-BOTDA分布式光纤技术　；参考：《岩石力学与工程学报》2016年S1期

【摘要】：光纤传感技术是滑坡监测领域较新的方法,通过在白水河滑坡前缘采用定点固定加直接埋设的方式并行布设应变式光纤和温度补偿式光纤,开展地表变形监测。根据PPP-BOTDA分布式光纤理论,对应变式光纤和温度补偿式光纤的应变数据进行温度补偿处理,得到光纤因变形而引起的实际应变。利用巴特沃斯低通滤波去噪方法,比较4组不同采样频率下的滤波效果及残差,确定滤波器阶数n和截止频率Wn。为表征2次监测数据之间的差异,选取光纤2次监测曲线与固定横轴的面积差作为评判指标,获取光纤沿线面积差,得到面积差与光纤应变差异程度之间为正相关关系,同时与野外实测数据进行对比分析。结果表明,采用PPP-BOTDA技术进行滑坡地表变形监测时,利用巴特沃斯滤波器进行去噪处理,并采用应变面积差表征光纤应变差异程度的分析结果,与野外空间地理位置上吻合度较高,对光纤技术在滑坡监测中的应用具有一定的借鉴意义。
[Abstract]:Optical fiber sensing technology is a new method in landslide monitoring field. Ground deformation monitoring is carried out by using fixed point and direct embedding in the leading edge of Baishui River landslide.According to PPP-BOTDA distributed fiber theory, the strain data of strain-type fiber and temperature-compensated fiber are processed by temperature compensation, and the actual strain caused by deformation of fiber is obtained.By using Butterworth low-pass filter de-noising method, the filtering effect and residual error of four groups of different sampling frequencies are compared, and the filter order n and cut-off frequency W _ n are determined.In order to characterize the difference between the two monitoring data, the area difference between the two optical fiber monitoring curves and the fixed transverse axis is selected as the evaluation index, and the area difference along the fiber line is obtained, and the positive correlation between the area difference and the fiber strain difference is obtained.At the same time, it is compared with the field measured data.The results show that the Butterworth filter is used to Denoise the landslide surface deformation monitoring with PPP-BOTDA technique, and the strain area difference is used to characterize the analysis result of the fiber strain difference degree.It is of great significance for the application of optical fiber technology in landslide monitoring.
【作者单位】：中国地质大学工程学院;
【基金】：国家重点基础研究发展计划(973)项目(2011CB710600) 国家自然科学基金重点项目(41230637) 中央高校基本科研业务费专项资金资助项目(CUGL150822)~~
【分类号】：P642.22

【相似文献】