Double Tied Arch Double Tied Arch bridge

Double Tied Arch Double Tied Arch bridge

5th KoreaKorea-Japan Joint Seminar on Steel Bridges
Double Tied Arch bridge
January 8, 2011
Woo--Jong, Kim
Woo
DM Engineering Co., Ltd. 66-2 Segi Bldg. Bangii-Dong, Songpa-gu, Seoul, Korea
TEL : +82-2-424-7272 FAX : +82-2-424-7924
www.dm-eng.com
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Contents
• About me
• Recent 4 bridges designed in Korea
1 New span length:
2 New construction scheme:
3 New structural system:
4 New structural shape:
Dandeong bridge, 2009
Baekjeon bridge, 2009
Chunsa bridge, 2010
Gyopo bridge, 2010
Today’s main topic
• Gyopo bridge, Double tied arch bridge
• Conclusion
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About me
NAME : Woo-Jong, Kim
DATE OF BIRTH : November 11, 1959
EDUCATION : Ph.D. in Civil Eng.
(Seoul National University, 1990)
LICENSE : Professional Engineer(1990, Structure)
EMPLOYMENT RECORD :
SAMWOO, YOOSHIN, DASAN
1984-1999
President, DM Engineering Co., Ltd. 1999-present
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1 New span length :
Dandeong bridge
2009 design by DM
Dandeong-Island
JJok-Island
Munyeo-Island
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Suspension bridges with single pylon
Elche Bridge, 165m (Spain)
Oakland Bay Bridge, 385m (USA)
Liede Bridge, 219m (China)
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2 New construction scheme : Baekjeon bridge
Original Design
ABUT A
<Section>
ABUT B
Is there more economical solution?
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3 New structural system :
Chunsa bridge
2010 design by DM
-Road width: 12.5 m
-Box width:
16.1 m
-Deck height: 2.6 m
1. FCM+Steeldeck
2. Very Stable during
construction
3. No tie Down
4. Small Cable Amount
5. More Open & Dynamic
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A Romantic bridge road
2010 design by DM
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4 New structural shape :
Gyopo bridge
2010 design by DM
PSC Box
PSC Box (FCM)
Double Tied Arch
PSC Box (FCM)
PSC Box
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Bridge site: Pyongtaek, 65km south from Seoul
Seoul
Pyongtaek
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Design philosophy
1.
As a river crossing bridge connecting the New United States Forces
Korea (K-6 base camp), Special one is necessary.
2.
A long-span bridge is necessary for navigation channel.
3.
As a long-span bridge with single-track railroad, the enhancement of
structural performance is required.
4. Smooth image is preferred in order to differentiate with adjacent
Extradosed Bridge.
Double Tied Arch bridge
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Concept of Double Tied Arch
Normal arch
Tie member
Double Tied Arch
Tie member
• One tie is in main arch, but the other is attached to side span.
• The stiffness of this bridge is increased .
• Hopefully, this shape will be considered to be more elegant than
single arch.
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Profile view of Double Tied Arch
2010 design by DM
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Structural effects of Double Tied Arch
Single Tied Arch
Double Tied Arch
① The compression of arch rib is reduced by 12%
② The tension of main span is reduced by 12%
③ The moment of main span is reduced by 50%
④ The displacement of main span is reduced by 10 %
⑤ The moment of side span is reduced by 38%
⑥ The displacement of side span is reduced by 28%
The 2nd ties make all deformations smaller both in the side
spans and in the main span.
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General Arrangement
Lower Upper
Plan
Profile
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Cross section
•
Cross section
Girder section
•
6,600
4,600
800
800
200
0.143
2,300
1,450
200
1
23,250
9,758
Arch crown section
•
3.114
1000
1.114
1000
0.143
2.250
2.250
Cover
1
Hanger
9,758
Cover
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Materials
• Steel
Bottom Flange of
Arch Rib
SM490Y-K15
Web of
Stiffening Girder
SM490Y-K15
Web of
Stiffening Girder
SM490Y-K15
Top Flange of
Stiffening Girder
SM490Y-K15
Web of
Stiffening Girder
SM490Y-K15
Parts of lamella tear resistant steel
• Concrete & rebar
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Design Loads
-
Design load : LS-22
Design speed : 70km/h (Entrance Railroad)
• Train load (LS-22)
longitudinal
lateral
• Impact factor (i)
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Structural safety
•
•
All stress are carefully checked by ASD.
Due to the long and shallow bridge, critical safety happens in
the buckling check.
Section A-A
Position
Section B-B
Section C-C
Section D-D
1
2
3
4
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Bending
stress
result
129.0
176.8
157.9
121.0
133.1
allow
210.0
210.0
210.0
210.0
210.0
Shear
stress
result
9.29
6.42
60.9
6.5
7.2
allow
110.0
110.0
110.0
110.0
110.0
Composition stress check
0.59
0.27
0.59
0.27
0.27
Buckling check
-
-
0.94
0.84
0.88
Total check
OK
OK
OK
OK
OK
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Fatigue check
•
Maximum fatigue stress reaches 90% of allowable stress.
Arch rib
Stiffening girder
1. Web-flange joints
1. Web-flange joints
3. Diaphragm joints
3. Diaphragm joints
2. Stiffener-flange joints
Position
Arch
rib
Girder
2. Stiffener-flange joints
Fatigue Stress (MPa)
Examination
Position
Stress
Categories
Result
Allow
1
B
45.02
112.0
OK
2
B
47.95
112.0
OK
3
C
36.28
70.0
OK
1
B
83.84
112.0
OK
2
B
83.89
112.0
OK
3
C
63.40
70.0
OK
Check
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FE Analysis
•
•
FE Analysis was done at the connection parts.
Maximum stress reaches 93% of allowable stress.
fmax top
fmax bottom
fmax (= 194.23 MPa) < fa (= 210.00 MPa) OK
fmax (= 195.11 MPa) < fa (= 210.00 MPa) OK
fmin top
fmin bottom
fmin (= 121.99 MPa) < fa (= 210.00 MPa) OK
fmin (= 142.70 MPa) < fa (= 210.00 MPa) OK
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Seismic analysis
•
•
The acceleration factor is 15.4% of gravity.
No concerned matter happens in seismic design.
Seismic Glade
Analysis
Conditions
First Grade
(1,000-year
Return period)
Risk Factor
Seismic Zone
Factor
Acceleration
Factor
1.4
0.11
(Zone Factor Ⅰ)
1.4×0.11
=0.154g
Site Coefficients Analysis Method
1.5
(Soil Type Ⅱ)
Time-History
Analysis
(Average Value)
Analysis
Modeling
Results
• Transverse Mode (T=3.4233sec)
• Longitudinal Mode (T=1.3641sec)
• Vertical Mode (T=0.6055sec)
• Modal Mass Coefficient
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Dynamic analysis
•
Vertical displacement, vertical acceleration, distortion and end
rotation are carefully checked.
Natural Frequency (Double Tied Arch)
f=1.565Hz
Vertical Displacement
• Max value:34.714mm < Allow:185.700mm, OK
Critical Speed of Train
Distortion
Vertical Acceleration
• Max value:3.625m/sec2 < Allow:5.0m/sec2, OK
End Rotation
• Design speed : 70km/h
• Vcr = f × seff
(Entrance railroad)
where :
- f : Natural frequency
- Seff : Effective beating interval
Seff(m)
Vcr(km/h)
13.950m
78.59 km/h
• Max value:0.087mm < Allow:1.5mm, OK
• Max value:0.002526rad < Allow:0.0100rad, OK
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Construction
• River Conditions
• Construction Method
1. Erection of side span segments and main span bents
H.W.L
(High Water Level)
106.04m
(100-year flood)
M.W.L
(Median Water Level)
102.50m
Design Flood Level
6,900m3/sec
(100-year flood)
River’s Breadth
B=815.8m
Depth (M.W.L)
7.20m
(Maximum depth)
2. Erection of main stiffening girder and tie members
3. Erection of arch ribs segments
4. Close arch ribs and remove bents
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Side span of main bridge
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Main span erection
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Aeroview 1
2010 design by DM
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Twilight view
2010 design by DM
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Conclusions
Many interesting bridges are designed and constructed
nowadays in Korea. Recently designed 4 bridges are
introduced.
- New span length:
- New construction scheme:
- New structural system:
- New structural shape:
Dandeong bridge, 2009
Baekjeon bridge, 2009
Chunsa bridge, 2010
Gyopo bridge, 2010
Especially for Gyopo bridge, double tied arch concept is
developed and introduced against small width and long
span.
Thanks
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