r - The Hong Kong Polytechnic University

Y(+ve)
Y T
Temperature Distribution
in Deck Cross Section
=
+ +
Measured
Temperatures
(Elevation)
Effective
Bridge
Temperature
Linear
Differential
Temperature
T T E
T L
( )
Self-Equilibrating
Temperature
With reference to above diagram, let the measured mean temperature in a part of the cross-section of A i
having its centroid distance Y i
from the neutral axis of the cross-section be T i
, the material of the part
having coefficient of thermal expansion and modulus of elasticity be respective α i
and E i
.
The Effective Temperature is computed as:
T
E
=
n
∑
i=
1
n
∑ ( E i α i A i
)
i=
1
E
i
α
i
A
i
T
i
The Differential Temperature is computed as:
T
E
=
n
∑ ( Ei
αi
Ai
( Ti
− TE
) Yi
)
i=
1
n
∑
i=
1
⎛
⎜
Ei
αi
⎝
2
y ⎞
i
A ⎟
i
Y
T ⎠
The Self-Equilibrating Temperature is computed as:
T
SE
=
( T − T )
i
E
Yi
− TL
Y
Figure 12 Formulas of Major Temperature Parameters
T
Type of
Input Data
Type of Data
Processing
Type of Data
Classification
Type of Data
Analysis
Type of Derived
Parameters
Type of Plots
TMU-1
TMU-2
TMU-3
TMU-4
TMU-5
TMU-6
TMU-7
GPS
Buf
Data Editing
Temperature
Data
Classification
Selection of
Data at the same
time period as
the Temperature
Data considered
Data Editing &
Classification
Steel Deck
Temperature
Steel Tower
Skin
Temperature
Concrete
Tower
Temperature
Concrete
Deck
Temperature
Stay Cable
Temperature
Air
Temperature
& Relative
Humidity
Asphalt
Pavement
Temperature
Vertical
Displacement
of Bridge-Deck
Longitudinal
Displacement
of Bridge-Deck
Longitudinal
Displacement
of Tower-Top
Sectional
Temperature
Distribution
Analysis
in terms of
Effective
Temperature,
Differential
Temperature &
Self-Equilibrating
Temperature
Time-Averaging
Statistics
Analysis
Time-Averaging
Statistics
Analysis
Effective Temperature
in Steel Deck
Effective Temperature
in Steel Tower Skin
Effective Temperature
in Concrete Tower
Effective Temperature
in Concrete Deck
Effective Temperature
in Stay Cable
Effective Temperature
in Asphalt Pavement
Differential Temperature
in Steel Deck
Differential Temperature
in Concrete Deck
Differential Temperature
in Concrete Tower
Air Temperature at
Above, Inside & Below
Deck Section
Air Temperature at Inside
& Outside Tower Section
Vertical Deck Displacement
at ¼, ½, & ¾ Main-Span
Longitudinal Deck
Displacement at Tower
Longitudinal Tower
Displacement at Tower-Top
Time-Series Plots of All Raw
& Processed Data
Hourly, Daily, Monthly &Yearly
Variation Plots of Effective
Temperatures in respective
Steel Deck, Steel Tower Skin,
Concrete Tower, Concrete
Deck, Stay Cable & Asphalt
Pavement with associated Air
Temperatures as references
Plots of Maximum & Minimum
Variations of Differential
Temperatures in respective
Steel Deck, Concrete Tower
& Concrete Deck
Plots of Maximum, Mean &
Minimum Variations of
Vertical Deck Displacement at
¼, ½ & ¾ Main-Span with
derivations of Thermal
Displacement in mm per °C
Plots of Maximum, Mean &
Minimum Variations of
Longitudinal Deck Displacement
at Towers with derivations
of Thermal Displacement
in mm per °C
Plots of Maximum, Mean &
Minimum Variations of
Longitudinal Tower
Displacement at Tower-Tops
with derivations of Thermal
Displacement in mm per °C
Figure 13 Flow Diagram of Customized Software Tools for Temperature Monitoring
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