APSS2010, 2 Aug., Tokyo

Contents

• Chinese bridges –Historic bridges –Modern bridges Chinese Bridges and Health Monitoring Systems • Structural health monitoring (SHM) systems –SHM for bridge in China Limin Sun –Case study –SHM for Donghai Bridge – Department of Bridge Engineering, Performance diagnosis – Tongji University, Shanghai, China Consideration on design of SHM system

Limin Sun, Tongji.Univ., China APSS2010 1 Limin Sun, Tongji.Univ., China APSS2010 2

Chinese historic bridges

Chinese historic bridges Pingan Bridge (BC1152), Fujian

Step Bridge, Zhejiang

Zhaozhou Bridge (BC605), Hebei Limin Sun, Tongji.Univ., China APSS2010 3 Limin Sun, Tongji.Univ., China APSS2010 4

Chinese historic bridges (cont.) Chinese historic bridges (cont.)

Hong Bridge , Henan Lounge Bridge, Zhejiang

Luding Bridge (BC1702), Sichuan

Chengyang Bridge (BC1924), Guangxi Limin Sun, Tongji.Univ., China APSS2010 5 Limin Sun, Tongji.Univ., China APSS2010 6

Limin Sun, Tongji Univ. 1 APSS2010, 2 Aug., Tokyo

Chinese historic bridges (cont.) Summary（1）

• Bridge structural types –girder, arch, suspension, cable-stayed

• Materials –timber, stone, iron & steel, concrete, CFRP? Qiantang River Bridge (BC1937), Zhejiang • Durability –stone > wood >? iron & steel, concrete

Wuhan Yangtze River Bridge (BC1957), Hubei Limin Sun, Tongji.Univ., China APSS2010 7 Limin Sun, Tongji.Univ., China APSS2010 8

Chinese modern bridges

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Major cable-stayed bridges completed or under construction in China continue （L≥400m） Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Steel‐ 2nd Chongqing Concrete concrete 6 Bridge over Yangtze Chongqing 444 1996 1 Nanpu Bridge Shanghai 423 1991 Beam Composed River Beam

Yunyang Bridge Hubei Concrete 2 414 1993 7 Xupu Bridge Shanghai 1996 1996 Hybrid Beam over Han River Prov. Beam

Steel‐ Steel‐ concrete concrete 3 Yangpu Bridge Shanghai 602 1993 8 Ting Kau Bridge Hongkong 475 1997 Composed Composed Beam Beam Tongling Bridge Anhui Concrete Kap Shui Mun 4 over Yangtze 432 1995 9 Hongkong 430 1997 Hybrid Beam Prov. Beam Bridge River

2nd Wuhan Bridge Hubei Concrete Shantou Queshi Guangdon 5 over Yangtze 400 1995 10 518 1998 Hybrid Beam Prov. Beam Birdge g Prov. River

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continue continue

Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Baishazhou Bridge Hubei Junshan Bridge Hubei Steel Box 11 618 2000 Hybrid Beam 16 460 2002 over Yangtze River Prov. over Yangtze River Prov. Girder

Steel‐ Qingzhou Bridge Fujian concrete Ehuang Bridge over Hubei Concrete 12 605 2001 17 480 2003 over Min River Prov. Composed Yangtze River Prov. Beam Beam

2nd Nanjing Bridge Jiangsu Steel Box Zhejiang 13 628 2001 18 Taoyaomen Bridge 580 2003 Hybrid Beam over Yangtze River Prov. Girder Prov.

Steel‐ Jingzhou Bridge Hubei Concrete Donghai Bridge concrete 14 500 2002 19 Shanghai 420 2005 over Yangtze River Prov. Beam (Navigation Span) Composed Beam

Dafosi Bridge over Concrete 3rd Nanjing Bridge Jiangsu Steel Box 15 Chongqing 450 2002 20 648 2005 Yangtze River Beam over Yangtze River Prov. Girder

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Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Anqing Bridge Steel Box Junshan Bridge Hubei Steel Box 21 Anhui Prov. 510 2005 16 460 2002 over Yangtze River Girder over Yangtze River Prov. Girder

Runyang Jiangsu Steel Box Ehuang Bridge over Hubei Concrete 22 Bridge(N) over 406 2005 17 480 2003 Prov. Girder Yangtze River Prov. Beam Yangtze River

Zhejiang Fengjie Bridge Concrete 18 Taoyaomen Bridge 580 2003 Hybrid Beam 23 Chongqing 460 2006 Prov. over Yangtze River Beam

Steel‐ Donghai Bridge concrete Zhanjiang Bay Guangdong Hybrid 19 Shanghai 420 2005 24 480 2006 (Navigation Span) Composed Bridge Prov. Beam Beam

3rd Nanjing Bridge Jiangsu Steel Box Shibangou Bridge Concrete 20 648 2005 25 Chongqing 450 2007 over Yangtze River Prov. Girder over Yangtze River Beam

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Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Hangzhou Bay Zhejiang Steel Box 26 Bridge (Navigation 448 2007 Sutong Bridge over Jiangsu Steel Box Prov. Girder 31 1088 2008 Span) Yangtze River Prov. Girder

Kangjiatuo Bridge Concrete Zhejiang Steel Box 27 Chongqing 460 2008 32 Jintang Bridge 620 2008 over Yangtze River Beam Prov. Girder

Tianxingzhou Yibin Bridge over Sichuan Concrete Hubei 28 460 2008 33 Bridge over 504 2008 Steel Truss Yangtze River Prov. Beam Prov. Yangtze River

Changshou Bridge Concrete 29 Chongqing 460 2008 over Yangtze River Beam 34 Stongcutters Birdge Hongkong 1018 2008 Hybrid Beam

Steel‐concrete Guanyinyan Bridge Shanghai Bridge Steel Box 30 Chongqing 436 2008 Composed 35 Shanghai 730 2010 over Yangtze River over Yangtze River Girder Beam

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Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

2nd Hejiang Bridge Sichuan Concrete 41 420 2012 36 Minpu Bridge Shanghai 708 2010 Steel Truss over Yangtze River Prov. Beam

Edong Bridge over Hubei Hybrid Xiangshan Port Zhejiang Steel Box 37 926 2010 42 688 2012 Yangtze River Prov. Beam Bridge Prov. Girder

Jingyue Bridge Hubei Hybrid Zhejiang Steel Box 38 816 2010 43 Jiashao Bridge 428 2012 over Yangtze River Prov. Beam Prov. Girder

Steel‐ Steel‐ Zhejiang concrete 2nd Jiaojiang Zhejiang concrete 39 Ningbo Bridge 468 2011 44 480 2013 Prov. Composed Bridge Prov. Composed Beam Beam

Erqi Bridge over Hubei Hybrid Xiazhang Bay Fujian Steel Box 40 616 2011 45 780 2013 Yangtze River Prov. Beam Bridge Prov. Girder

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continue Major suspension bridges completed or under construction in China （L≥400m） Main Yr.of NO. Pictures Name Location Type Main Yr.of Span/m Completion NO. Pictures Name Location Type Span/m Completion Anqing railway Anhui 46 Bridge over 580 2013 Steel Truss Xizang Prov. 1 Dazi Bridge 500 1984 Steel Truss Yangtze River Prov.

Dongshuimen Shantou Bay Guangdon Concrete 47 Bridge over Chongqing 445 2013 Steel Truss 2 452 1995 Bridge gProvg Prov. Beam Yangtze River

Tongling highway XIlin Bridge over Hubei Steel Box Anhui 3 900 1996 48 and railway Bridge 630 2014 Steel Truss Yangtze River Prov. Girder Prov. over Yangtze River Fengdu Bridge over Gangzhuao 4 Chongqing 450 1996 Steel Truss Guangdon Steel Box Yangtze River 49 Bridge(QIngzhou 458 2014 g Prov. Girder Navigation Span) Steel Box 5 Tsingma Bridge Hongkong 1377 1997 Girder

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continue continue

Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Zhongxian Bridge Guangdon Steel Box 11 Chongqing 560 2001 Steel Truss 6 Humen Bridge 888 1997 over Yangtze River g Prov. Girder 2nd Wanzhou Jiangyin Bridge Jiangsu Steel Box 12 Bridge over Chongqing 580 2004 Steel Truss 7 1385 1999 over Yangtze River Prov. Girder Yangtze River

Runyang Bridge(S) Jiangsu Steel Box Fujian Steel Box 13 1490 2005 8 Haicang Bridge 648 2000 over Yangtze River Prov. Girder Prov. Girder

Steel Box Yangluo Bridge Hubei Steel Box 9 Egongyan Bridge Chongqing 600 2000 14 1280 2007 Girder over Yangtze River Prov. Girder

Yinchang Bridge Hubei Steel Box Guizhou 10 960 2001 15 Balinghe Bridge 1088 2007 Steel Truss over Yangtze River Prov. Girder Prov.

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Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion

Zhejiang Steel Box Guizhou 16 Xihoumen Bridge 1650 2008 21 Beipanjiang Bridge 636 2009 Steel Truss Prov. Girder Prov.

Huangpu Zhujiang Guangdon Steel Box Jiangxi Steel Box 17 1108 2008 22 Kanzhou Bridge 408 2010 Bridge g Prov. Girder Prov. Girder

Shanxi Steel Box Hunan 18 —— Huluhe Bridge 700 2008 23 Aizhai Bridge 1176 2011 Steel Truss Prov. Girder Prov.

Yuzui Bridge over Steel Box Guangxi Steel Box 19 Chongqing 616 2008 24 Shuangyong Bridge 430 2011 Yangtze River Girder Prov. Girder

Hubei Hunan 20 Siduhe Bridge 900 2009 Steel Truss 25 —— Lishui Bridge 856 2012 Steel Truss Prov. Prov.

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continue Major arch bridges completed or under construction in China （L≥400m）

Main Yr.of Main Yr.of NO. Pictures Name Location Type NO. Pictures Name Location Type Span/m Completion Span/m Completion Nanxi Bridge Reinforced Sichuan Steel Box Wanxian Bridge 26 over Yangtze 820 2012 1 Chongqing 420 1997 Concrete Prov. Girder over Yangtze River River Arch ／Deck 4th Nanjing Steel Box Jiangsu Steel Box 27 Bridge over 1418 2013 Lupu Bridge Shanghai 550 2003 Arch/throug Prov. Girder 2 Yangtze River h Taizhou Bridge Steel Tube Jiangsu Steel Box 28 over Yangtze 1080 2013 Wushan Bridge Concrete Prov. Girder 3 Chongqing 460 2004 River over Yangtze River Arch /half‐ Maanshan through Steel Box 29 Bridge over Anhui Prov. 1080 2013 Steel Truss Girder Guangdon Yangtze River 4 Xinguang Bridge 428 2006 Arch/throug g Prov. h Steel Truss Caiyuanba Bridge 5 Chongqing 420 2006 Arch/throug over Yangtze River h

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continue Summary（2） Main Yr.of NO. Pictures Name Location Type Span/m Completion • Since 1990, China has built many long span (>400m) Steel Tube Rongxi Zhijinghe bridges 6 Hubei Prov. 430 2007 Concrete Arch Bridge /Deck –cable-stayed Chaotianmen 38 + 11 (u.c.) =49, the longest: Sutong Bridge (1088m) Steel Truss 7 Bridge over Yangtze Chongqing 552 2008 Arch/through –suspension River 22 + 7 (u.c.) =29, the longest: Xihoumen Bridge (1650m) Steel Truss – 8 DihBidDaninghe Bridge Chongqi ng 400 2008 arch Arch／Deck 9 + 2 (u.c.) =11, the longest: Chaotianmeng Bridge (552m) Steel Box Zhejiang 9 Yongjiang Bridge 450 2009 Arch /half‐ Prov. through • Maintenance Needs after Construction Boom Steel Tube - short coming of design codes; 4th Xiangjiang Hunan 10 400 2011 Concrete Arch Bridge Prov. - too fast construction speed; /through - unexpected increasing of traffic demands. Steel Tube 1st Hejiang Bridge Sichuan 11 510 2012 Concrete Arch over Yangtze River Prov. /through Limin Sun, Tongji.Univ., China APSS2010 29 Limin Sun, Tongji.Univ., China APSS2010 30

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Summary（2）(cont.)

• Operation conditions of bridges –corrosion and rupture of steel wires in stay cables, hangers and PC tendons –cracks of concrete structures –deterioration of non-structural components (e.g. pavement) –human errors ? accident Broken stay cable due to corrosion of Fall down of Tian Zuang Tai Bridge due Haiyin Bridge (1995) to broken of PC cables (2004)

a) Cracks on top slab of box-girder b) Concrete expansion on tower wall Cracks of concrete bridges

Pavement damage of Bridge (2003)

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Ship Collision, Jiujiang Bridge Bridge structural monitoring system Guangd ong (2007)

Construction or Design ? Fenghuang Bridge, Hunan (2007) More than 60 people were killed Limin Sun, Tongji.Univ., China APSS2010 33 Limin Sun, Tongji.Univ., China APSS2010 34

Outline Bridges with structural Health Monitoring Systems in China

• SHM for long span bridges in China • SHMS of Donghai Bridge - Donghai bridge and its SHMS - Monitoring data (1 year, 2007) - what we get - Performance diagnosis - how to use data • Summary

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SHMS for Bridges in China

• More than 100 large bridges have installed SHMS in China since 1999.

• The primary objectives of the SHMS: SHM for Donghai Bridge –To provide supports for maintenance during operation –To obtain information of structural performance under extreme events, for assessing structural safety - Donghai bridge and its SHMS –To validate design assumptions and design loads, and to provide - Monitoring data (1 year, 2007) - what we get data for consummating the design code - Performance dignosis - how to use data

• The cost of a SHMS generally take about 0.25-2.0% of the total construction cost of a bridge.

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Donghai Bridge Shanghai SHMS for Donghai Bridge • Donghai bridge is a linkage connecting Shanghai and Yangshan Island deep water Port. The linkage is • Donghai Bridge is the only way linking the port to Shanghai. about 32 km long and consists of 2 cable stayed bridges and a large It is a very important structure. number of spans of continuous and simply supported bridges. • Donghai Bridge is the first large scale cross-sea bridge project • The bridges have been completed in China and it lies on soft clay. The bridge carries heavy and opened to traffics in 2005. The container trucks. Therefore, the durability against ocean health monitoring system was Port environment, the un -uniform settlement of foundation and completed in Oct., 2006. the fatigue of steel deck are seriously concerned.

• The structural health monitoring system for Donghai Bridge (SHMSDH) was designed to automatically collect the data of environment and structural response.

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Monitored sectors Monitored items

Luchao Port Outline of monitored spans of • Environment of bridge site including temperature, Donghai Bridge Bottomland area wind speed, earthquake, wave and scour; (70-50m continuous girder spans) Sub-navigation channel Bridge (70+120+120+70m continuous girder spans) • Static and dynamic response of bridge including

Main-navigation channel Bridge deformations of towers of cable-stayed bridges, (420m cable-stayed bridge) 5X60m continuous deflections of continuous girders, girder spans un-uniform settlements of foundations,

Kezhushan Bridge displ acemen ts of d ampers and expensi on j oi nt s, (332m cable-stayed bridge) Sub-navigation channel Bridge strains of girders, (80+140+140+80m continuous girder spans) vibration of girders and towers, Open air station to corruption tensions of stay cables;

5X70m continuous girder spans • Durability of structure including fatigue of steel Yangshan Port structures and chloride corrosion of concrete.

Sub-navigation channel Bridge (90+160+160+90m continuous beam spans)

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Primary sensor technologies used Evaluation systems • On-line evaluation • FBG sensors for strains and temperatures The on-line evaluation system is an automatic system. - The system can analyze the data than to judge preliminarily the safety • GPS for monitoring deformations of structure. - The system is able to automatically make a decision of whether it is need to alarm the management authority and to immediately start the • Fatigue sensor for fatigue of bridge girders off-line evaluation system.

• Off-line evaluation • 478 sensors in total The off-line evaluation system will process some advantaged analysis, (169 for main-navigation channel bridge) such as structural static analysis, mode analysis, correlated analysis between the bridge behaviors and environmental factors and so on. The system needs massive structural analysis and judgments by experts then gives an comprehensive evaluation of structural condition.

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Main features of SHMSDH

Accessible via internet The real-time signal data collecting system

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Monitoring data – for evaluation under extreme loads Ship collision

• Typhoon

• Earthquake

0.025 mode4 before • 0550.55 mode4 after Explosion 0.02 mode1 before 0.5 mode1 after 0.015 mode2 before 0.01 0.45 mode2 aftere Frequency (Hz)

Modal damping ratioModal damping 0.005 0.4 0 0 500 1000 1500 0 500 1000 1500 • Time (min) Time (min) Ship collision 2007-01-01 00:00:00 2007-01-02 00:50:00 2007-01-01 00:00:00 2007-01-02 00:50:00 2007-01-02 01:35:00 2007-01-03 02:35:00 2007-01-02 01:35:00 2007-01-03 02:35:00 (a) 船撞前后模态频率的比较 (b) 船撞前后模态阻尼比的比较

A comparison between before and after collision A comparison between before and after collision 1 1 MAC(1,1) before MAC(2,2) before MAC(1,1) after MAC(2,2) after 0.995 0.99

0.99 0.98 2007-01-02 2007-01-02

MAC 00:50:00~2007-01-02 MAC 00:50:00~2007-01-02 0.985 01:35:00 0.97 01:35:00

0.98 0.96

0.975 0.95 0 500 1000 1500 2000 2500 3000 0 500 1000 1500 2000 2500 3000 Time (min) Time (min) 2007-01-01 00:00:00 2007-01-03 02:35:00 2007-01-01 00:00:00 2007-01-03 02:35:00

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Wenchuan Earthquake in 2008

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Performance diagnosis of Donghai Bridge

Luchao Port O utline of m onitored spans of D onghai B ridge B ottom land area (70-50m continuous g irder sp ans) Sub-navigation channel Bridge (70+120+120+70m continuous girder spans)

M ain-navigation channel B ridge (420m cable-stayed bridge) 5X60m continuous Performance diagnosis girder spans

Kezhushan Bridge (332m cable-stayed bridge) Sub-navigation channel Bridge (80+140+140+80m continuous girder spans) O p en air station to corruption

5X70m continuous girder spans Yangshan Port

Sub-navigation channel Bridge (90+160+160+90m continuous beam spans)

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Data analysis – how to make use of the data measured ?

„Sensitive parameter related to damage global vs. local in this study, vibration-based parameter (frequency) „ Parameter variation due to damage (or boundary condition) 169 sensors Type of sensor Quantity Measurement Location + environmental effects (temp., traffic) Thermometer 1 air temperature(At) Deck Thermometer 24 steel temperature(St) Deck Thermometer 20 concrete temperature(Ct) Deck/Tower „ Uncertainty of parameters Anemometer 1 wind speed/direction(Ane) Tower Weather station 1 wind speed/direction, humidity(Aws) Deck statistic method, based on long term data GPS 3 displacement Tower/Deck FBG strain sensor 36 steel dynamic strain Deck FBG strain sensor 12 concrete dynamic strain Tower/Deck Accelerometer 19 acceleration Deck Accelerometer 8 acceleration Tower Fatigue sensor 24 Deck Extensometer 4 displacement Expansion joint Cable force sensor 8 cable force(Cf) Cable Displacement sensor 2 displacement Deck

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Data analysis – prepare for damage identification ? Environmental factors - Temperature

Is it possible to separate? 40

30

C) Air 0 Temp. Total response of structure measured 20 Data in 2007 temperature( 10

0 0 60 120 180 240 300 360 time (d) 40 40 Response due to Response due to 30 Concrete 30 Steel Temp. C) C) environment change structural damage 0 Temp. 0 20 20 temperature ( temperature ( 10 10

0 0 0 60 120 180 240 300 360 0 60 120 180 240 300 360 time (d) time (d)

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Environmental factors - Traffic 3rd modal freq. vs. Temp.

Vertical acc. RMS Temp 3rd freq -> equivalent traffic load

4

3

2 rms (gal)

1

0 0 60 120 180 240 300 360 time (d) Chinese Newyear Mayday GW National Day GW

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PSD of Freq. and Temp. Correlation between Freq. and Temp.

Temp 3rd freq 7th freq

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Displ. at expansion joint and Temp. Experimental validation

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Experimental validation Correlation coef. of 1st freq

20.5 cycle air vertical wind wind humidity (h) temperature acc. RMS speed direction 20.0 6 0.807 0.891 0.168 0.068 0.038 8 0.323 0.691 0.092 0.093 0.211 19.5 12 0.732 0.915 0.472 0.491 0.359

y (Hz) 24 0.409 0.476 0.406 0.164 0.109 c

19.0 28 0.027 0.969 0.026 0.132 0.002 33.6 0.181 0.949 0.026 0.182 0.172 frequen 42 0.098 0.796 0.063 0.583 0.058 18.5 56 0.017 0.684 0.148 0.252 0.060 84 0.038 0.924 0.119 0.074 0.372 18.0 -10 0 10 20 30 40 168 0.541 0.950 0.053 0.033 0.310 temperature (0C)

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Estimation of effects by temp. and vibration level Alarm at abnormal structural conditions Y

YT=+β01ββθε + 2 +

Y : structural frequency T : air temperature boundary condition changes

θ: structural vibration level (traffic) 0.008 99% ε : remain ε 0.006 99.9% 0.004 b : coefficient fitted based on the measurement 0.002 0.000

(1 year) -0.002

-0.004 residual frequency (Hz) -0.006

-0.008 0 60 120 180 240 300 360 time (d) typhoon

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Summary（3）

• More than 100 large bridges have installed a SHMS in China. Generally, the cost of a SHMS will take about 0.25-2.0% of the total of construction of a bridge.

• SHM for Donghai Bridge was introduced. The response data during typhoon, earthquake, explosion and ship collision Consideration on design of SHM system were automatically collected for rapid evaluation. - based on Vulnerability Analysis • Based on long term monitoring data, it is possible to distinguish the structural response induced by temperature change (wind & traffic?) from the entire response. This may improve the feasibility of damage identification by using statistic methods.

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Outline Background

• SHM system design: • Background –two of the most important tasks: allocation of sensors (where and what?), alarming algorithm • Two-parameters structural vulnerability –semi-empirical; not optimized; analysis method • Vulnerability: • Applications in SHM s ystem desig n –regarded as structural performance susceptibility to local damage of structure; • Case studies –depends on element strength, system (topology), loads, failure mode, etc. • Summary • Research purpose: –propose concepts and methods of structural vulnerability analysis; –find the most vulnerable components which are need to be monitored and corresponding alarming threshold once damages occur.

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Two-parameters structural vulnerability analysis Two-parameters structural vulnerability analysis (cont.) • Concepts and definitions proposed in order to assess structural vulnerability quantitatively: • Damage process of structural system –Damage Event: exterior disturbance causing damages of structural system –Damage Scenario: set of damaged structural components –Damage Consequence: degradation severity of structural performance after being damaged –Failure Path: series of components causing failure of whole structural system –Failure Scenario: set of components causing failure of whole structural system –Robustness: ability to maintain original structural performance after being damaged –Vulnerability: sensitivity of structural performance to local damages –Vulnerable Scenario: failure scenario with relatively higher vulnerability Limin Sun, Tongji.Univ., China APSS2010 94 Limin Sun, Tongji.Univ., China APSS2010 95

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Two-parameters structural vulnerability analysis Two-parameters structural vulnerability analysis (cont.) (cont.)

• CI is the influence degree of damage scenario to structural performance. P − P CI = DS DS P whPhere P: structural lf performance

• MI is the proportion of the damage scenario to the overall structural system. • (a) The structural vulnerability assessment in various damage severities MI --- the severity of a specified damage scenario for a given damage scenario. MI∈[0,1] • (b) The structural vulnerability assessment in various damage scenarios.

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Two-parameters structural vulnerability analysis Applications in SHM system (cont.) ƒ Application of vulnerability analysis in allocation ƒ Pareto optimization of sensors

Minimize F = F1(DS), F2 (DS)

0 ≤ F1(DS) ≤1

0 ≤ F2 (DS) ≤1

where F1(DS)=1-CIDS， F2(DS)=MIDS.

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Applications in SHM system (cont.) Case study ƒ Cable-stayed bridge (half model) ƒ Application of vulnerability analysis in early alarming system

ƒ Damage scenario: cable breakage ƒ Structural performance: (1) maximum stress; (2) girder buckling

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Case study (cont.) Case study (cont.)

ƒ The variation of structural performance to different damage scenarios ƒ Pareto frontier maximum stress

buckling

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Case study (cont.) Case study (cont.)

ƒ Pareto frontier buckling ƒ Cables need to be monitored (circled)

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Summary(4)

• This study investigated the quantitative analysis method of structural vulnerability and its application in bridge SHM system. Thanks ! • The proposed two-parameters structural vulnerability & analysis method is based on the influence magnitude of Questions ? damage scenario to structural performance and the proportion of the damage scenario in the overall structural system. Acknowledgement • The structural vulnerability analysis results may be This research was supported by the key program of NSFC (Grant No. 50538020) and the key research project of Chinese State Key Laboratory for Disaster Reduction in Civil employed as a reference for designing sensors Engineering (Grant No. SLDRCE08-A-05). allocation and alarming threshold of bridge SHM system. Co-researchers: Dr. Danhui Dan, Dr. Zhi Sun, Dr. Hongwei Huang Dr. Zhihua Min, Dr. Gang Yu Haishan Wu, Yi Zhou, Meiju Jiao, Shouwang Sun, Xueliang Li

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