Application of Distributed Fiber Optic Sensing Technology in the Transportation Engineering Monitoring

Transcription

1 Application of Distributed Fiber Optic Sensing Technology in the Transportation Engineering Monitoring Bin Shi, Ph.D., China August 5, 2015 ISSAEST, Fairbanks, AK, USA, August 2-5, 2015

2 The Monitoring Characters of Transportation Engineering Linear and longer Large scale Complicated Geological condition Harsh working environment

3 Developing tendency of monitoring technology 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.

4 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

5 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".

6 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

7 DFOS based Monitoring Prototype for Infrastructure

8 DFOS Family Multi-use Fibre Bragg Grating (FBG) DFOS Family Scatter light Optical time domain reflectometry(otdr) Raman OTDR(ROTDR) Brillouin OTDR (BOTDR) Brillouin OTD Analysis(BOTDA) Brillouin Optical frequency domain analysis (BOFDA)

9 DFOS Monitoring System

10 FBG Product Series FBG Products Fiber grating Grating series FBG Sensors Modulator s Monitoring System FBG Modulators Pressure & osmometer Displace & Stress Temperature Strain & Deformation 迷你土压力计 土压力计 微型渗压计液位计静力水准仪孔压计位移计 锚索测力计钢筋应力计 温度计 ( 工业 ) 温度计 ( 岩土 ) 温度计 ( 电力 ) 表面应变计缆式应变计埋入应变计

11 Hand FBG Modulator 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 Optical interface type Maximum FBG Sensor Capacity per channel 20 Other indexes Display type Can be queried FC/APC Resolution 480*320 Communication interface Power supply Power consumption (W) inch LCD screen USB Operating temperature( ) -10 ~ 50 Operating humidity Storage temperature( ) -20 ~ 60 Storage humidity Dimensions(length * width * height)( mm) Weight(kg) 1.3 9VDC(With the AC power adapter) 0~80% (no condensation) 0~80% (no condensation) 251*150*43

12 Portable FBG Modulator Optical indexes Number of channels 2 Wavelength range (nm) 1525 ~ 1565, 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

13 Manufacture of FBG sensors FBG etching Coating Assembling Welding

14 DSS Product Series DSS Products Modulators Sensing cables Monitoring System Services Surface Interior Point

15 DSS Modulators (1) 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 S OFDR ( Luna,USA ) item Measure mode Max. measure accuracy Spatial resolution Measure distance Measure frequency parameter Single-end 2με 1-5mm Max 100m 5-100HZ

16 DSS Modulators (2) BOFDA ( FibrisTerre,Germany ) Item parameter Measure mode Double-end Measure accuracy 2 με Spatial resolution 20 cm Measure distance Max 25 Km Measure time S BOTDA ( Neubrex,Japan ) Item parameter Measure mode Double-end Max. measure accuracy 7.5 με Spatial resolution 5 cm Measure distance Max 25 Km Measure time S

17 Manufacture of Sensing Optical Fiber Fiber drawing and coating equipment Bare fiber Fiber extrusion equipment Tight package soft cable

18 Manufacture and connection of smart GFRP anchor Smart GFRP anchor

19 Sensing Cables Strain sensing cable Strain & Temp sensing cable

20 Metal-based S & T sensing belt Porous copper belt fiber 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 Production line Metal-based sensing belt

21 Installed on the steel-pipe pile Steel-pipe pile Point welding Glued by epoxy End protection

22 Steel-strand sensing cable Item Optical fiber type Cable type Fiber quantity 1 Cable sectional dimensions Parameters G.652B metal-based Φ5 Tensile strength (N) 930 Cable weight (kg/km) 38 Steel-strand twisted and weaved equipment Steel-strand sensing cable

23 Installed in the cast-in-place pile Strapping End protection Grouting Pile forming

24 Steel-strand sensing cable Implanted in borehole weight dropped into borehole grouting protection

25 Soft tight-packed strain sensing cable Item Parameters Optical fiber type G.652B Cable type HY Fiber quantity 1 Cable sectional dimensions Φ Tensile strength (N) Cable weight (kg/km) 3-8 Implanted into PHC Pile grooving Embedded in Epoxy seal End protection

26 Point fixed strain sensing cable Implanted into soil Item Parameters Optical fiber type G.652B Cable type point to point Fiber quantity 1 Cable sectional dimensions Φ Tensile strength (N) 120 Step length (m) 1-20 trenching point fixation laying the fiber covering

27 DTS Product Series DTS Products Modulator Sensing cable Monitoring System Service ROTDR ROFDR 金属基装温度传感光缆 金属基装温度传感光缆 单层钢丝加强中心管束感温光缆 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 钢丝加强铠装光缆 中心管束式温度传感光缆 扁平型纤维加强温度传感光缆

28 Carbon fibre heatable temperature sensing cable 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

29 Case one: Xuanwu-lake tunnel FOS monitoring

30 Project scheme Selection of the optical fiber 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%;

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33 Installation of BOTDR sensing fibers 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)

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35 The Layout of Optical Fiber Installation Fiber cable

36 The installation profile of Sensing fibers Southern tunnel Southern tunnel Location of sensing fiber Groove size

37 Tridimensional layout of sensing fibers installation on the arch

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40 Deformation distribution of expansion and contraction joint along the Tunnel (1) Position No. Position ( from South Entrance) m Maximum (mm) Minimum (mm) SP SP SP (near center) SP SP SP SP

41 { 应变 /% Deformation distribution of expansion and contraction joint along the Tunnel (2) 0.6 expansion 温度伸缩缝 and contraction joint 传感光纤末端 Sensing fiber end Concrete 混凝土衬砌 section From 自 /9/2013 年 9 月 30 to 日至 3/11/ 年 11 月 3 日 Distance/m 距离

42 strain temperature 气温 ( ) 40 应变 ( ) temperature 气温 日期 date S4 线典型点有效应变变化 Negative correlation between temperatures and strain values of Line S

43 Abnormal values monitored by BOTDR at 90m 异常 Abnormal value m 段应变 section 异常 Abnormal value

44 Case two: Application into the pavement monitoring

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46 100 strain Some of test results (1) Cracking area extension compress ion 应变 ( ) distance 0 小时 31 小时 55 小时 80 小时 104 小时 distance 距离 (m) The surface strain distribution after grouting 104hrs

47 strain Some of test results (2) 应变 ( ) 小时 31 小时 55 小时 80 小时 104 小时 distance 距离 (m) The strain distribution of interior steel rebar S9 after grouting 104hrs

48 Application of Raman OTDR(ROTDR) 电力系统 建筑系统 海洋开发 化工系统

49 Raman OTDR(ROTDR) 高速公路地基温度监测系统 The DTS of the pavement of highway

50 Raman OTDR(ROTDR) 高速公路路面结冰监测系统 The DTS of the road surface freezing of highway

51 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.

52 International Forums on Opto-electronic Sensor-based Monitoring in Geo-engineering (OSMG) 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. Now five Forums have been successfully held in 2005, 2007, 2010, 2012, respectively.

53 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 )

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