当前位置: X-MOL 学术Geomat Nat. Hazards Risk › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Research and application of an improved internal thrust force measurement system for rock and soil mass based on OFDR
Geomatics, Natural Hazards and Risk ( IF 4.5 ) Pub Date : 2021-06-01 , DOI: 10.1080/19475705.2021.1927859
Pu Wang 1 , Yimin Liu 2, 3
Affiliation  

Abstract

Internal thrust force of unstable rock and soil mass is an essential parameter for prediction of many geological hazard. Currently, fiber bragg grating (FBG) and optical time-domain reflectometer (OTDR) are widely used to measure internal stress of unstable rock and soil mass. However, these methods have disadvantages such as low spatial resolution and the paucity of distributed measurements. This paper develops a quasi-distributed thrust measurement system based on an optical frequency domain reflectometer (OFDR). Firstly, we design an optical fiber stress sensor head using the characteristics of the optical fiber microbending effect. And then, the cubic spline interpolation method is used to compensate for the nonlinear effects of the OFDR. Finally, we implement a laboratory experiment of lateral stress to make error calibration. As a result, the OFDR sensing system achieved a spatial resolution of 20cm by using a 500m test fiber, maximum measurement pressure reached 1.059MPa and relative error is 8.9%. We implemented OFDR in the Chenjiagou landslide located at the Three-Gorge of Chongqing in China. The results showed that this system can accurately locate six fiber stress sensors within the landslide over a range of 0 ∼ 420m, obtaining the lateral thrusts as well.

更新日期:2021-06-01
down
wechat
bug