bridge assessment & monitoring
TRANSCRIPT
Structure Health
Monitoring (SHM) System
SysEng (s) Pte. Ltd.
Why SHM?
Public safety
Protect Owner Property and Investment
Help on infrastructure planning a decision making
The SHM Approach
System Identification Geometry
Boundary conditions
Material properties
Live load identification Current loading
Loading history?
FEM modelling
Determination of limit states Strength
Deflection
Fatigue
Overview of Dynamic Test
Setup on Bridge
mode: 1 f=6.49Hz, zeta=0.26%
Impact Excitation
Shaker Excitation
Dynamic Data
Acquisition
System Dynamic Data
Analysis Software
Structure modeling
Software
Type of Dynamic Sensor
Type of installed sensor:
Displacement sensor -- Relative or absolute displacement
Accelerometer -- Acceleration
Resistive Strain Gage and Load Cell – Strain or Stress
Temperature and Humidity sensor -- Structural and
environmental temperature
Anemometer -- Wind speed and direction
Accelerometer with impact hammer or shaker -- Directly
applied dynamic forces (Force Excitation source)
Dynamic SHM System
Acceleration
signal module
Onosite
data Processing
controller
40 CH
channel
Analog
Input
module
Acceleration
signal module
temperature and
humidity sensor
6x on 6 diffrenet
location
displacement sensor
2x on both expansion
joint
Anemometer
signal module
Accelerometer
1x on deck
2x on stay cable
Ultrasonic Anemometer
- 2x on deck
- 1x on top of plyon
Strain Gage
signal module
displament
signal module
Resistance Based
Load Cell on stay cable
12x on stay cablewireless
communication
module
`
Bridge Frequency Response
Amplitude
Time
Frequency (Hz)
Amplitude
Bridge Damping Coefficient
Time
Amplitude
Damping coeff
Bridge Data Analysis
Bridge Modeling
mode: 1 f=8.31Hz mode: 2 f=9.34Hz
mode: 3 f=10.71Hz mode: 4 f=12.95Hz
mode: 5 f=17.15Hz mode: 8 f=27.91Hz
Modes of vibration
f1 = 0.760 Hz f2 = 0.854 Hz f3 = 1.111 Hz
What SHM can achieve?
Analysis of structural integrity
Damage detection
Analysis of aging and useful life
Behavior under new loadings
Help to provide solution for the bridge
problem
Help to protect historical structure
Predict the lifespan of bridge
under different loading condition
Axle loading
Remaining life
(years)
16.5 115
18.5 106
22.5 40
Help to suggest solution for
the bridge problem
Results used to design Tuned Mass Damper to fix vibration problem identified by ARUP and confirmed by walking test
300 400 500 600 700 800 900 1000 1100 1200 1300-200
-150
-100
-50
0
50
100
150
200
Changi Bridge: Lateral acceleration in crowd test
mm
/se
c2, p
eo
ple
seconds
no. of people
acc for up to 150 people
Help to assess the effect of the
bridge upgrading project
Girder 15
-2
0
2
4
6
8
10
12
14
16
0 100 200 300 400
before upgrading
120 year strain
Girder 24
-2
0
2
4
6
8
10
12
14
16
0 200 400 600
micro-strain
Gum
bel varia
te
before upgrading
120 year strain
Girder 15
-2
0
2
4
6
8
10
12
14
16
0 100 200 300 400
after upgrading 120 year strain
Girder 24
-2
0
2
4
6
8
10
12
14
16
0 200 400 600
micro-strain
Gu
mb
el va
ria
te
after upgrading
120 year strain
before
after
Help to detect crack on the
bridge
Amplitude (%)
0 20 40 60 80 100
Dam
pin
g (
%)
0
1
2
3
4
5
Cracks
increase
Chemical changes
List of Major Bridge in China
Donghai Bridge 东海大桥 , longest bridge in Asia, longest cross-sea bridge in the world
Hangzhou Bay Bridge 杭州湾大桥 , second longest bridge in the world, longest trans-oceanic bridge in the world
Kap Shui Mun Bridge 汲水门大桥 , longest road-rail cable-stayed bridge in the world
Lugou Bridge 卢沟桥, historically and architecturally significant
Lupu Bridge 卢浦大桥 , longest arch bridge in the world
Nanjing Yangtze River Bridge 南京长江大桥 6,772 meters in length
Precious Belt Bridge 宝带桥 , architecturally significant historical bridge
Stonecutters Bridge 昂船洲大桥 , second longest cable-stayed span, after Sutong Bridge
Sutong Bridge 苏通大桥 , Yangtze cable stayed bridges, has the longest main span in the world
Tsing Ma Bridge 青马大桥 , longest road-rail suspension bridge in the world
Wanxian Bridge 万县长江大桥 , longest concrete arch bridge in the world
Zhaozhou Bridge 赵州桥 , an open-spandrel stone segmental arch bridge
List of Major Bridge in China