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ISSAEST, Fairbanks, AK, USA, August 2-5, 2015
Application of Distributed Fiber Optic
Sensing Technology in the Transportation
Engineering Monitoring
Bin Shi, Ph.D.
Nanjing University, China
August 5, 2015
Nanjing University The Monitoring Characters of Transportation Engineering
Linear and longer Large scale
Complicated Geological condition Harsh working environment
Nanjing University
The conventional monitoring technologies have some
disadvantages such as point monitoring, difficult to install,
poor anti-interference, poor durability and poor stability etc.,
so they don’t meet the monitoring requirements of modern
transportation engineering.
Developing tendency of monitoring technology
Nanjing University
In past decades, fiber optic sensing (FOS)
technology is rapidly developing, and its
monitoring advantages with distributed,
long-distance, small size , totally immune to
EMC perturbations, long lifetime etc.
provide a new way to monitor transportation
engineering and other infrastructure
engineerings
Nanjing University Fiber Optic Sensor Root
Charles Kuen Kao GBM,KBE,FRS, FREng (born 4 November 1933) is a Chinese-born Hong
Kong, American and British electrical engineer and physicist who pioneered
in the development and use of fiber optics in telecommunications. Kao,
known as "Father of Fiber Optic Communications", was jointly awarded the
2009 Nobel Prize in Physics for "groundbreaking achievements concerning
the transmission of light in fibers for optical communication".
Nanjing University What is Distributed FOS?
Point Quasi-distributed Fully Distributed
•Point : such as Mechelson and Fibry-Perot sensor
•Quasi-distributed: FBG (Fiber Bragg Grating )
•Fully Distributed: OTDR, ROTDR, BOTDR/A
Nanjing University
DFOS –based Monitoring Prototype for Infrastructure
Nanjing University
2015-8-10 8
DFOS Family
DF
OS
Fam
ily
Fibre Bragg Grating (FBG)
Optical time domain reflectometry(OTDR)
Raman OTDR(ROTDR)
Brillouin OTDR (BOTDR)
Brillouin OTD Analysis(BOTDA)
Multi-use
Scatter light
8
Brillouin Optical frequency domain
analysis (BOFDA)
……………
Nanjing University DFOS Monitoring System
Nanjing University
Fiber
grating
Grating
series
FBG
Sensors
Modulator
s
Monitoring
System
FBG
Products
迷你
土压力计 微型渗压计 液位计 静力水准仪 孔压计 位移计
温度计
(工业) 钢筋应力计 埋入应变计
温度计
(电力) 表面应变计 缆式应变计 锚索测力计 土压力计
温度计
(岩土)
Pressure & osmometer Displace & Stress Temperature Strain & Deformation
FBG Product Series
FBG Modulators
Nanjing University
Optical indexes
Number of channels 1
Wavelength range (nm) 1525 ~ 1565
Wavelength resolution (pm) 1
Repeatability (pm) 5
Response Frequency 1~5
Dynamic range (dB) 40
Channel spectrum Can be queried
Optical interface type FC/APC
Maximum FBG Sensor Capacity per channel 20
Other indexes
Display type 3.5 inch LCD screen
Resolution 480*320
Communication interface USB
Power supply 9VDC(With the AC power adapter)
Power consumption (W) 5
Operating temperature(℃) -10 ~ 50
Operating humidity 0~80% (no condensation)
Storage temperature(℃) -20 ~ 60
Storage humidity 0~80% (no condensation)
Dimensions(length * width * height)(mm)
251*150*43
Weight(kg) 1.3
Hand FBG Modulator
Nanjing University
Optical indexes
Number of channels 2
Wavelength range (nm) 1525 ~ 1565,1510-1590
Wavelength resolution (pm) 1
Scan Frequency(Hz/channel) 2
Dynamic range (dB) 50
Channel spectrum Can be queried
Power supply 9VDC
communication USB,RF,Internet,WiFi
Operating temperature(℃) -10 ~ 50
Dimensions(mm) 325*275*140
Weight(kg) 4.4
Portable FBG Modulator
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FBG etching Coating
Welding Assembling
Manufacture of FBG sensors
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Modulators Sensing cables
Monitoring System
Services DSS Products
DSS Product Series
Surface Interior Point
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BOTDR
(EI41,China)
item parameter
Measure mode Single-end
Measure accuracy 45 με
Spatial resolution 50 cm
Measure max. Distance Max 80 Km
Measure time 120-600S
DSS Modulators (1)
item parameter
Measure mode Single-end
Max. measure accuracy 2με
Spatial resolution 1-5mm
Measure distance Max 100m
Measure frequency 5-100HZ OFDR
( Luna,USA )
Nanjing University
Item parameter
Measure mode Double-end
Max. measure accuracy 7.5 με
Spatial resolution 5 cm
Measure distance Max 25 Km
Measure time 60-300S
DSS Modulators (2)
Item parameter
Measure mode Double-end
Measure accuracy 2 με
Spatial resolution 20 cm
Measure distance Max 25 Km
Measure time 60-300S
BOFDA
( FibrisTerre,Germany )
BOTDA
( Neubrex,Japan )
Nanjing University
Fiber drawing and coating equipment Bare fiber
Fiber extrusion equipment Tight package soft cable
Manufacture of Sensing Optical Fiber
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Smart GFRP anchor
Manufacture and connection of smart GFRP anchor
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Strain sensing cable
Strain & Temp sensing cable
Sensing Cables
Nanjing University
Item Parameters
Optical fiber type G.652B
Cable type metal-based
Fiber quantity 2 (S&T)
Cable sectional dimensions 15mm*0.15 mm
Tensile strength (N) 280
Cable weight (kg/km) 18
Metal-based S & T sensing belt
fiber
Porous copper belt
Production line Metal-based sensing belt
Nanjing University
Steel-pipe pile Point welding
Glued by epoxy End protection
Installed on the steel-pipe pile
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Item Parameters
Optical fiber type G.652B
Cable type metal-based
Fiber quantity 1
Cable sectional
dimensions Φ5
Tensile strength (N) 930
Cable weight (kg/km) 38
Steel-strand sensing cable
Steel-strand twisted and weaved equipment Steel-strand sensing cable
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Strapping End protection
Pile forming Grouting
Installed in the cast-in-place pile
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Implanted in borehole
weight dropped into borehole grouting protection
Steel-strand sensing cable
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Item Parameters
Optical fiber type G.652B
Cable type HY
Fiber quantity 1
Cable sectional dimensions Φ 0.9-2.0
Tensile strength (N) 25-38
Cable weight (kg/km) 3-8
grooving Embedded in Epoxy seal End protection
Implanted into PHC Pile
Soft tight-packed strain sensing cable
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trenching point fixation laying the fiber covering
Item Parameters
Optical fiber type G.652B
Cable type point to point
Fiber quantity 1
Cable sectional dimensions Φ 4.5-8.0
Tensile strength (N) 120
Step length (m) 1-20 Implanted into soil
Point fixed strain sensing cable
Nanjing University
• Modulator Sensing
cable Monitoring
System Service DTS Products
DTS Product Series
扁平型纤维加
强温度传感光
缆
金属基装温
度传感光缆 金属基装温度传感光缆
高强度铠
装测温光
缆
钢丝编织网
铠装光缆
塑封芳纶夹钢
丝编织管铠装
光缆
无缝管铠
装感温光
缆
中心管束
式温度传
感光缆
钢丝加
强铠装
光缆
单层钢丝加
强中心管束
感温光缆
ROTDR ROFDR
Nanjing University
Item Parameters
Optical fiber type MM
Cable type heatable
Fiber quantity 1-3
Cable sectional dimensions Φ 3-8
Tensile strength (N) 350
Heating power(w/m) 6-20
Carbon fibre heatable temperature sensing cable
Nanjing University
Case one:
Xuanwu-lake tunnel FOS monitoring
Nanjing University
Based on many experiments, the jacketed SM optical fiber
from Corning Co Ltd is selected as sensor.
Specification:
8.3/125/900/m (core/cladding/protective coating);
Weight: 0.9 kg/km;
Maximal tension: 6.6 N;
Minimum bending radius: 3.0 cm
Compressive strength: 200 N/m;
Working temperature: -20~+80 C;
Working wavelength: 1.3~1.5 m;
Refractive index error: 0.36%;
Project scheme
Selection of the optical fiber
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Nanjing University
Nanjing University
FOS sensing fibers were installed on the surface of
the concrete wall and arch with three configurations:
(1)Overall Adhesion Method (OAM)
(2)Fixed-point Adhesion Method (FAM)
(3) -shaped Fixed-point Adhesion Method (-FAM)
Installation of BOTDR sensing fibers
Nanjing University The Layout of Optical Fiber Installation
Fiber
cable
Nanjing University The installation profile of Sensing fibers
2015-8-10 36
Southern tunnel Southern tunnel
Location of sensing fiber
Groove size
Tridimensional layout of sensing fibers installation on the arch
Nanjing University
Nanjing University
Nanjing University
Deformation distribution of expansion and contraction
joint along the Tunnel (1)
2015-8-10 40
Position No.
Position ( from South Entrance)
m
Maximum
(mm)
Minimum
(mm)
SP 13
450
0.139
-0.022
SP 15
405
0.128
-0.025
SP 17
355(near center)
0.094
-0.021
SP 21
256
0.103
-0.004
SP 23
190
0.135
-0.015
SP 25
38
0.127
-0.008
SP 27
114
0.142
-0.007
Nanjing University
2015-8-10 41
600 800 1000 1200 1400 1600 1800
-0.2
0.0
0.2
0.4
0.6
应变
/%
距离 /m
传感光纤末端
自 2003年9月30日至2003年11月3日
温度伸缩缝
{
混凝土衬砌
Deformation distribution of expansion and contraction
joint along the Tunnel (2)
expansion and contraction joint
Sensing fiber end
Concrete section From 30/9/2013 to 3/11/2013
Distance/m
Nanjing University
2003-5-22
2003-6-23
2003-7-21
2003-8-26
2003-9-30
2003-10-21
2003-11-17
2003-12-18
2004-1-16
2004-2-22
-400
-200
0
200
400
600
800
0
10
20
30
40
气温 (
℃)
应变
()
日期
525
595
626
735
830
920
1040
1130
1250
1370
1460
1550
1640
1730
气温
S4线典型点有效应变变化
2015-8-10 42
temperature
str
ain
tem
pera
ture
date
Negative correlation between temperatures and strain values of Line S4
Nanjing University
Abnormal values monitored by BOTDR at 90m
2015-8-10 43
540 560 580 600 620 640-200
0
200
400
600
800
1000异 常
异 常
545- 635段应变
2003-4-25
2003-5-12
2003-6-2
2003-7-7
2003-7-30
Abnormal value
Abnormal value 545-635m section
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Case two: Application into the pavement monitoring
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0 2 4 6 8
-120
-100
-80
-60
-40
-20
0
20
40
60
80
100
应变
()
距离 (m)
0 小时 31 小时 55 小时 80 小时 104 小时
The surface strain distribution after grouting 104hrs
extension compression
Cracking area
distance
str
ain
distance
Some of test results (1)
Nanjing University
0 2 4 6 8
-120
-100
-80
-60
-40
-20
0
20
40
60
80
100
应变
()
距离(m)
0 小时 31 小时 55 小时 80 小时 104 小时
The strain distribution of interior steel rebar S9 after grouting 104hrs
str
ain
distance
Some of test results (2)
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电力系统
海洋开发
建筑系统
化工系统
Application of Raman OTDR(ROTDR)
高速公路地基温度监测系统
Raman OTDR(ROTDR)
The DTS of the pavement of highway
高速公路路面结冰监测系统
Raman OTDR(ROTDR)
The DTS of the road surface freezing of highway
Nanjing University Conclusion
DFOS, as an innovative sensing technology, is very useful
and powerful to monitoring transportation engineering. However,
some of further R & D work need to do, such as: low-cost
demodulator; special sensing cable for measurement of large
deformation; improvement of manufacture and installation
technology; software to deal with huge data, and code making
etc.
However we do believe that DFOS will have a huge
application in the infrastructure monitoring including
transportation and geo-engineering.
Nanjing University
In 2005,under the support of National Natural Science Foundation of China, our team set
up International Forums on Opto-electronic Sensor-based Monitoring in Geo-engineering
(OSMG) in Nanjing University. Now five Forums have been successfully held in 2005,
2007, 2010, 2012, 20014 respectively.
International Forums on Opto-electronic Sensor-based Monitoring in Geo-engineering (OSMG)
Nanjing University Acknowledgment
It is grateful that the project is supported by
National Basic Research Program of China(973 Program)(NO.
2011CB710605)
National Key Project of Scientific and Technical Supporting
Programs Funded by Ministry of Science and Technology of China
(NO. 2012BAK10B05),
The State Key Program of National Natural Science of China
(Grant No. 41230636 )
Nanjing University