Structural Health Monitoring of Cable Supported Bridges

Heungbae “Harry” Gil

• KOREA EXPRESSWAY CORPORATION

• RESEARCH DIRECTOR

• hgil@ex.co.kr

ORGANIZATION OR COMPANY LOGO

Cable supported bridges in Korea

Structural Health Monitoring System(SHMS)

SHMS for bridges in Korea

Findings from long-term SHMS operation

Issues with SHMS

Order of Presentation

CSB in Korea

CSB in Korea

CSB in Korea

CSB in Korea

CSB in Korea

CSB in Korea

CSB in Korea

CSB in Korea

Structural Health Monitoring

Definition

The integration of a sensory system, a data acquisition system,

a data processing and archiving system, a communication

system, structural modeling system that provides information

on demand in real time about any significant change or

damage occurring in the structure on a continuous or periodic

basis

by R. M. Ellis & P.D. Thompson from ISIS Canada &

International Society for Structural Health Monitoring of

Intelligent Infrastructure

Structural Health Monitoring System

Structural Health Monitoring System

Why install SHMS?

Evaluate structural conditions or performances under

operational and environmental conditions

Critical area monitoring(stress, fatigue,..)

Damage detection

Extreme event or abnormal performance

location, time, extent, level of seriousness

Understanding of new structural systems & materials

Structural Health Monitoring System

Sensors

Strain gauges(foil, vibrating wire, FBG)

LVDT, Tiltmeters(Inclinometers)

Accelerometers, Seismometers

Thermometers, Anemometers

Acoustic Monitoring Sensors

GNSS (GPS) Receivers

CCTV

SHMS for Bridges in Korea

Brief HistoryFailure of in-service and under-construction bridges in 1990s

Monitoring system was installed to detect problems with existing bridges from late 1990s

SHMS have been installed on new cable supported bridges from early 2000s

SHMS for Bridges in Korea

SHMS for Bridges in Korea

SHMS for Bridges in Korea

SHMS for Bridges in Korea

Korea Infrastructure Safety Corporation(KISTEK)

SHMS for Bridges in Korea

(Korea Infrastructure Safety Corporation)

Findings from SHMS Operation

Effects of environmental and operational loading on structures Temperature, heavy traffic, wind

Design check Changes in structural systems

Management of extreme events Typhoon, earthquake, fire

Environmental Loading

Temperature effects on the Seohae Bridge

Temperature vs. Thermal movement

(Time lag phenomenon)Temperature change

Environmental Loading

Temperature effects on the Seohae Bridge

Temperature vs. Natural frequencies

Highly linear relationship

Inversely proportional

Environmental Loading

Temperature effects on the Yongjong Bridge

0

50

100

150

200

250

300

350

400

-20 -10 0 10 20 30 40

E2-중앙E2-외측

신축변위량(mm)

온도(oC)

Displacement of Expansion Joints(mm)

Air Temperature(°C)

-59-43

13

477168

9498

65

37

0

-30-20-28

6

465569

10182

71

39

5-9

-37-25

1540

7074778262

42

16

-24-35

-112

4460

84819070

45

-6

-42

3

6168769798

79

4224

-24-37-27

-147

-112-93

-59

-194

2423

-16-33

-79-102

-118

-91-79

-43-25

-12112

0

-64-87

-105

-132

-104-90

-40-24

519

6 0

-46

-76-98

-136

-101-88

-47

-18

92220

-3

-40

-103-91

-44-40

420

8 0

-45

-70

-124-113-125

24

-29

-58

-117

-102

slop = 0.20

-200

-150

-100

-50

0

50

100

150

200

01-J

an

Mar

May

July

Sep

Nov

02-J

an

Mar

May

July

Sep

Nov

03-J

an

Mar

May

July

Sep

Nov

04-J

an

Mar

May

July

Sep

Nov

05-J

an

Mar

May

July

Sep

Nov

06-J

an

Displacement of Expansion Joints(mm)

232~240mm/year

The bridge expands 46mm in every 10oC changewith a correlation coefficient of 0.995

Seasonal Behavior

Environmental Loading

Vortex-shedding (Jindo 2nd Bridge) 2011/4/19

Jindo 2nd

Jindo 1st

Windrose diagram(300 Degree)

Korea Dry Monsoon

(Northwesterly Wind)

• Type : Cable stayed bridge

• Year of completion : 2006. 4

• Length : L=484m(70+344+70)

• Width : B=12.55m

Operational Loading

Traffic loading on Seohae Bridge

-400.000

-350.000

-300.000

-250.000

-200.000

-150.000

-100.000

-50.000

0.000

50.000

100.000

20

16

-06

-30

00

:00

20

16

-06

-30

00

:40

20

16

-06

-30

01

:20

20

16

-06

-30

02

:00

20

16

-06

-30

02

:40

20

16

-06

-30

03

:20

20

16

-06

-30

04

:00

20

16

-06

-30

04

:40

20

16

-06

-30

05

:20

20

16

-06

-30

06

:00

20

16

-06

-30

06

:40

20

16

-06

-30

07

:20

20

16

-06

-30

08

:00

20

16

-06

-30

08

:40

20

16

-06

-30

09

:20

20

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-06

-30

10

:00

20

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-06

-30

10

:40

20

16

-06

-30

11

:20

20

16

-06

-30

12

:00

20

16

-06

-30

12

:40

20

16

-06

-30

13

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20

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-30

14

:00

20

16

-06

-30

14

:40

20

16

-06

-30

15

:20

20

16

-06

-30

16

:00

20

16

-06

-30

16

:40

20

16

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-30

17

:20

20

16

-06

-30

18

:00

20

16

-06

-30

18

:40

20

16

-06

-30

19

:20

20

16

-06

-30

20

:00

20

16

-06

-30

20

:40

20

16

-06

-30

21

:20

20

16

-06

-30

22

:00

20

16

-06

-30

22

:40

20

16

-06

-30

23

:20

Def

lect

ion

(m

m)

Measured Deflection of Stiffening Girder (North)

AVG MAX MIN

Operational Loading

Traffic loading on Seohae Bridge

Extreme Events

Typhoon

Extreme Events

Typhoon

Extreme Events

Earthquake

< Ground acceleration records at the Seohae Bridge >

Extreme Events

Cable fire of the Seohae Bridge

Extreme Events

Cable fire of the Seohae Bridge

(72D)

Extreme Events

Cable fire of the Seohae Bridge

(56D)

(57D)

Extreme Events

Cable fire of the Seohae Bridge

Extreme Events

Cable fire of the Seohae Bridge

Extreme Events

Cable fire of the Seohae Bridge

Extreme Events

Cable fire of the Seohae Bridge

Issues with SHMS

Issues with SHMS

Conclusion