â€œCurrent and Future Bridge Health Monitoring Systems in - SAMCO

“Current and Future Bridge Health Monitoring Systems in Hong Kong”

byEur Ing Dr. WONG, Kai-Yuen

TMCA Division, Highways DepartmentThe Government of the Hong Kong Special Administrative Region

HIGHWAYS DEPARTMENTTSING MA CONTROL AREA DIVISION

BRIDGE HEALTH SECTION

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Why Bridge Health Monitoring System is needed?

• Monitoring Structural Performance and Applied Loads

• Facilitating the Planning of Inspection and Maintenance

• Validating Design Assumptions and Parameters

• Updating and Revising Design Manuals and Standards

1. WASHMS refers to Wind And Structural Health Monitoring System.

2. Application: “wind sensitivity structures”, i.e. frequencylower than 1 Hz.

3. Existing Bridges with WASHMS:(i) Tsing Ma & Kap Shui Mun Bridges - LFC-WASHMS.(ii) Ting Kau Bridge - TKB-WASHMS.

4. Future Bridges with WASHMS:(i) The Cable-Stayed Bridge (Hong Kong Side) in

Shenzhen Western Corridor - SWC-WASHMS.(ii) Stonecutters Bridge - SCB-WASHMS.



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WASHMS

Hong Kong IslandHong Kong IslandHong Kong IslandLantauIslandLantauLantauIslandIsland

KowloonKowloonKowloon

New TerritoriesNew TerritoriesNew Territories

Tsing YiTsingTsing YiYi

ShekouShekouShekou

ShenzhenShenzhenShenzhen

Tuen MunTuenTuen MunMun

Yuen LongYuen LongYuen Long

Sha TinShaSha TinTin

Hong Kong International Airport

Hong Kong Hong Kong International International AirportAirport

Shenzhen Western Shenzhen Western CorridorCorridor

Stonecutters Bridge

Tsing Ma Bridge

Kap Shui Mun Bridge

Ting Kau Bridge

HIGHWAYS AREA DIVISION

DEPARTMENTTSING MA CONTROL BRIDGE HEALTH

SECTION

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Tsing Ma Bridge5



Kap Shui Mun Bridge6

Ting Kau Bridge 7

Kap Shui Mun Bridge

Tsing Ma Bridge

Ting Kau Bridge



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View of the 3 bridges from Southwest Corner of TMCA

The two cable-stayed bridges in Shenzhen Western Corridor



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Stonecutters BridgeHIGHWAYS DEPARTMENT

TSING MA CONTROL AREA DIVISIONBRIDGE HEALTH SECTION

Part 2System Architecture and Operation of WASHMS



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System Architecture of WASHMSThe four WASHMSs, i.e. LFC-WASHMS, TKB-WASHMS, SWC-WASHMS and SCB-WASHMS, are all configured into six integrating modules:

• Sensory System (SS)

• Data Acquisition and Transmission System (DATS)

• Portable Data Acquisition System (PDAS)

• Data Processing and Control System (DPCS)

• Structural Health Evaluation System (SHES)

• Portable Inspection and Maintenance System (PIMS)



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Part 3Current WASHMS



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Layout of Sensory System (SS)

Layout of SS and DAS in LFC-WASHMS (TMB Part)

Layout of SS and DAS in LFC-WASHMS (KSMB Part)

Layout of SS and DAS in TKB-WASHMS



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Details of Different Types of Sensory System

Accelerometers on Main Cable of Tsing Ma Bridge

Detail of Accelerometers Accelerometers



Accelerometers on Main Cable

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Accelerometers

Detail of Accelerometers on Longitudinal Stabilizing Cable

Accelerometers Mounted on Longitudinal Stabilizing Cable

Bi-axial Accelerometers on Longitudinal Stabilizing Cable of Ting Kau Bridge



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Dynamic Weigh-in-Motion Sensors



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Traffic Direction

Dynamic Weigh-in-Motion Sensors for Lantau Fixed CrossingHIGHWAYS DEPARTMENT




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Portable Data Acquisition System (PDAS)



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Portable Data Acquisition System for Field Vibration Measurement WorksField Measurement Works on Tsing Ma Bridge Mounting Portable Accelerometers for Suspenders



Battery Unit 1Battery Unit 2

Signal Conditioner (32 No. Channels)

Main Controller

Communication Unit

Remote Control Unit

UPS Unit

Isolation Transformer

PDAS and Portable Accelerometers

Accelerometers

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Data Processing and Control System (DPCS)



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The DPCS in LFC-WASHMS & TKB-WASHMS• One UNIX-Based 64-bit Alpha Server equipped with SPIDAR

(Modified), Customized MATLAB Software and MATLAB Data Analysis Suite for overall control of SS and DAs in LFC-WASHMS

• One UNIX-Based 64-bit Alpha Server equipped with SPIDAR (Modified), Customized MATLAB Software and MATLAB Data Analysis Suite for overall control of Ss and DAS in TKB-WASHMS

• Two 32-bit SGI Intel-Based (Quad-CPU) Visual Workstations equipped GPS Monitoring Software and MATLAB Data Analysis Suite for overall control of GPS including processing, analysis, display, archiving and storage of GPS data and Video Signals from CCTV Cameras

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Structural Health Evaluation System (SHES)



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The SHES for LFC-WASHMS & TKB-WASHMS

• One 64-bit UNIX-Based (Quad-CPU) Alpha Server equipped with MSC/NASTRAN, ANSYS/Multiphysics, ANSYS/LS-DYNA, ANSYS/FE-SAFE, Structural Dynamic-Tools and MSC/PATRAN

• One 64-bit UNIX-Based (Dual-CPU) Alpha Server equipped with Customized SPIDAR and MATLAB Data Processing Software

• One 64-bit UNIX-Based Alpha Workstation equipped with MSC/PATRAN



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Part 4Limitations of

Current WASHMS



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Limitations of Current WASHMS

• No Corrosion Monitoring

• Insufficient Software Facilities for Automatic Data Processing and Analysis

• No Automatic Facilities for Correlation between Measured Results and Performance Criteria given in Bridge Rating System*

• Insufficient Screens for Instant Display of Monitoring Results

Accelerometer & Seismometer 48

Anemometer 40

Temperature Sensor 388

Temperature & Relative Humidity 28

GPS Sensor 20

Displacement Sensor 34

Strain Gauge 515

Weigh-In-Motion Sensor 12

Digital Video Cameras 16

Corrosion Cells 30



Stonecutters Bridge - Locations of Sensors31

Section of Tower

Section of Deck Level

7 - Car LAR Trains

Wei

ght (

Tonn

es)

Bogie Number

Note : The measured bogie loads are derived from strain gauges installed in way-beams at Chainage 24662

Tsing Ma Bridge – Comparison between Measured and Design Bogie LoadsHIGHWAYS DEPARTMENT


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Screen Display of Instantaneous Displacement of Tsing Ma Bridge: Bridge-Deck, Suspension Cables and Tower-TopsHIGHWAYS DEPARTMENT


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Screen Display of Time Series Displacement of Tsing Ma Bridge : Bridge-DeckHIGHWAYS DEPARTMENT


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800

850

900

950

1000

1050

1100

1150

1200

1250

1300

00:00

03:00

06:00

09:00

12:00

15:00

18:00

21:00

00:00

03:00

06:00

09:00

12:00

15:00

18:00

21:00

Time (hours)

Disp

lace

men

t (m

m)

GPS (TMB Mid Span)

4600

4650

4700

4750

4800

4850

4900

4950

5000

5050

5100

00:00

03:00

06:00

09:00

12:00

15:00

18:00

21:00

00:00

03:00

06:00

09:00

12:00

15:00

18:00

21:00

Time (hours)

Disp

lace

men

t (m

m)

Level Sensor

20

25

30

35

40

00:00:00

03:00:00

06:00:00

09:00:00

12:00:00

15:00:00

18:00:00

21:00:00

00:00:00

03:00:00

06:00:00

09:00:00

12:00:00

15:00:00

18:00:00

21:00:00

Time (hours)

Tem

pera

ture

(oC)

Air Temperature

Effective Temperature

Comparison of Vertical Deck Displacement at TMB Mid-Span by GPS and Level Sensor Measurement with Temperature Variation for two consecutive days from 03-Aug-2003 00:00

Comparison of Vertical Deck Displacement at TMB Mid-Span by GPS, Accelerometers and Level Sensor Measurement

Tsing Ma Bridge - Deck Displacement Influence Lines by GPSHIGHWAYS DEPARTMENT


A B C D

Train Effect ignored

Travel Direction of Heavy Vehicle

A

B

C

D

Deck Section

M.W TowerCH23623 Sensor Location

T.Y TowerCH25000

Sensor LocationCH23623

+ ve µε Compression strain- ve µε Tension strainDesigned stress due to Live Load at SLS = ±60 MPa

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A1

A2

Time-series acceleration data for points A1 and A2

0 0.5 1 1.5 2 2.5 3 3.5 40

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

10.385Hz

Coherence for points A1 and A2

Auto power spectrum for points A1 and A2

0.385Hz

0.385Hz

A1A2

Deform: NORMAL_MODE, Mode 1:Freq.=0.38619: Eigenvectors, Translational

MSC. Patran 2001 r3 07-Apr-03 14:53:43

Fringe: NORMAL_MODE, Mode 1:Freq.=0.38619: Eigenvectors, Translational – (NON-LAYERED) (MAG)

Theoretical FEM for Kap Shui Mun Bridge (Theoretical frequency = 0.38619Hz)



Total No. of Grids = 10,914

Total No. of CBAR/ CBEAM = 24,234

Total No. of CQUAD4 = 42,906

Total No. of RBAR = 2,854

ModulusE cable = 1.95 x 1011 N/m2

E steel = 2.05 x 1011 N/m2

E concrete = 2.60 x 1010 N/m2

Mass Densityρcable = 8,200 kg/m3

ρsteel = 8,800 kg/m3

ρconcrete = 2,500 kg/m3

Total No. of Grids = 10,914

Total No. of CBAR/ CBEAM = 24,234

Total No. of CQUAD4 = 42,906

Total No. of RBAR = 2,854

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The Finite Element Model of Tsing Ma Bridge and List of Modelling Information



401st Vertical Flexural Deck and 1st Vertical Cable Mode

(Mode No. 2, Frequency = 0.11741 Hz)

No. of nodes 2799

No. of elements 5135

Beam 3021

Quad4 2114

No. of materials 4

No. of element properties 70



Finite Element Model of Kap Shui Mun Bridge41

(Mode No. 1, Frequency = 0.38619 Hz)1st Vertical Flexural Deck

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BRIDGE HEALTH SECTION 44

CONCLUSIONS

The WASHMS provides an effective and reliable means of bridge health evaluation which plays a key role in bridge maintenance and rehabilitation.



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Documents

â€œCurrent and Future Bridge Health Monitoring Systems in - SAMCO