scholarly journals Seepage and settlement monitoring for earth embankment dams using fully distributed sensing along optical fibers

2008 ◽  
Author(s):  
P. Y. Zhu ◽  
Y. Zhou ◽  
Luc Thévenaz ◽  
G. L. Jiang
Keyword(s):  
Optical Fibers ◽  
Distributed Sensing ◽  
Embankment Dams ◽  
Earth Embankment ◽  
Settlement Monitoring

scholarly journals Safety Inspection Strategy for Earth Embankment Dams using Fully Distributed Sensing

2011 ◽  
Vol 8 ◽  
pp. 520-526 ◽  
Author(s):  
Pingyu Zhu ◽  
Y.B. Leng ◽  
Y.Zhou ◽  
G.L. Jiang
Keyword(s):  
Distributed Sensing ◽  
Embankment Dams ◽  
Inspection Strategy ◽  
Earth Embankment

Simultaneous Calibration Method for Strain and Temperature of Distributed Sensing Optical Fibers

2014 ◽  
Vol 43 (12) ◽  
pp. 1206002 ◽  
Author(s):  
吕安强 Lv An-qianga ◽  
李永倩 LI Yong-qiana ◽  
李静 LI Jingb ◽  
陈永 CHEN Yonga
Keyword(s):  
Optical Fibers ◽  
Calibration Method ◽  
Distributed Sensing

New Monitoring Program of Transformer Substation Foundation Settlement

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jin-Lei Hu ◽  
Wen-Bo Wang ◽  
Zhemin Zhang ◽  
Kun Zhang ◽  
Kui Hua ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Monitoring Program ◽  
Time Domain Analysis ◽  
Foundation Settlement ◽  
Sensing Technology ◽  
Transformer Substation ◽  
Temperature Reference ◽  
Optical Time ◽  
Hardware Monitoring ◽  
Settlement Monitoring

Abstract In order to solve the problem of foundation settlement monitoring, this paper presents a monitoring program of substation foundation settlement, which is based on the distributed optical sensing technology. The composition of the hardware monitoring system and the wiring scheme of stress optical cables were described. The results of simulation experiment showed that the Brillouin optical time domain analysis could well meet the precision requirements of substation settlement monitoring. Moreover, the temperature reference optical fibers should be laid for temperature compensation. This paper can provide the basis for further prevention of substation foundation settlement.

scholarly journals Tests under irradiation of optical fibers and cables devoted to corium monitoring in case of severe accident in a Nuclear Power Plant

2020 ◽  
Vol 225 ◽  
pp. 08006
Author(s):  
G. Cheymol ◽  
L. Maurin ◽  
L. Remy ◽  
V. Arounassalame ◽  
H. Maskrot ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Nuclear Power ◽  
Carbon Coating ◽  
Hydrogen Diffusion ◽  
Coating Layer ◽  
Distributed Sensing ◽  
Severe Accident ◽  
Normal Operation ◽  
The Status

The DISCOMS project, which stands for “DIstributed Sensing for COrium Monitoring and Safety”, considers the potential of distributed sensing technologies, based on remote instrumentations and Optical Fiber Sensing cables embedded into the concrete floor under the reactor vessel, to monitor the status of this third barrier of confinement. This paper focuses on the selection and testing of singlemode (SM) optical fibers with limited RIA (Radiation Induced Attenuation) to be compliant with remote distributed instruments optical budgets, the ionizing radiation doses to sustain, and their reduction provided by the concrete basemat shielding. The tests aimed at exposing these fibers and the corresponding sensitive optical cables, to the irradiation doses expected during the normal operation of the reactor (up to 60 years for the European Pressurized Reactor), followed by a severe accident. Several gamma and mixed (neutron-gamma) irradiations were performed at CEA Saclay facilities: POSÉÏDON irradiator and ISIS reactor, up to a gamma cumulated dose of about 2 MGy and fast neutron fluence (E > 1 MeV) of 6 x 1015 n/cm2. The first gamma test permitted to assess the RIA at various optical wavelengths, and to select three radiation tolerant singlemode fibers (RIA < 5 dB/100 m, at 1550 nm operating wavelength). The second one was performed on voluminous strands of sensitive cables encapsulating the selected optical fibers, up to approximately the same accumulated dose, at two temperatures: 30°C and 80°C. A significant increase of the RIA, without any saturation tendency, appeared for fibers inserted into cables, correlated with the increase of the hydroxyl attenuation peak at 1380 nm. Molecular hydrogen generated by the radiolysis of compounds of the cable is at the origin of this phenomenon. A third gamma irradiation run permitted to measure the radiolytic hydrogen production yield of some compounds of a dedicated temperature cable sample. The efficiency of a carbon coating layer over the silica cladding, acting as a barrier against hydrogen diffusion, was also successfully confirmed. Finally, the efficiency of this carbon coating layer has also been tested under neutron irradiation, then qualified as a protection barrier against hydrogen diffusion in the optical fiber cores.

Application Study on a Detecting Tube for Deformation Settlement Monitoring for Earth Dike Based on Distributed Optical Fiber Sensors

2011 ◽  
Vol 103 ◽  
pp. 327-331
Author(s):  
Ping Yu Zhu ◽  
Hua Lei ◽  
Yuan Bao Leng
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fem Analysis ◽  
Optical Fiber Sensors ◽  
Earth Dam ◽  
The Finite Element Method ◽  
Fiber Sensors ◽  
Application Study ◽  
Distributed Optical Fiber ◽  
Settlement Monitoring

A monitoring structure has been designed to detect settlement using a tube with distributed optical fiber sensors inside. The strain of the optical fibers inside the detecting tube was calculated to estimate the settlement degree of earth dam. The Finite Element Method (FEM) analysis of the tube interaction with the earth dam by ANSYS software is applied to find the best installation location of the detecting tube.

Novel optical fibers for Brillouin-based distributed sensing

2013 ◽  
Author(s):  
Peter D. Dragic ◽  
John Ballato ◽  
Stephanie Morris ◽  
Alex Evert ◽  
Robert R. Rice ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Distributed Sensing
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