Outline of Japanese Design Specifications for Highway Bridges
22
44 th UJNR Panel Meeting 2013/02/20 Gaithersburg Outline of Japanese Design Specifications for Highway Bridges in 2012 Tetsurou KUWABARA (CAESAR,PWRI) Takashi TAMAKOSHI (NILIM) Jun MURAKOSHI (CESAR,PWRI) Yoshitomi KIMURA (CESAR,PWRI) Toshiaki NANAZAWA (CESAR,PWRI) Jun-ichi HOSHIKUMA (CESAR,PWRI) 1
Transcript of Outline of Japanese Design Specifications for Highway Bridges
44th UJNR Panel Meeting 2013/02/20 Gaithersburg
Outline of Japanese Design Specifications for Highway Bridges in 2012
Tetsurou KUWABARA (CAESAR,PWRI) Takashi TAMAKOSHI (NILIM)
Jun MURAKOSHI (CESAR,PWRI) Yoshitomi KIMURA (CESAR,PWRI)
Toshiaki NANAZAWA (CESAR,PWRI) Jun-ichi HOSHIKUMA (CESAR,PWRI)
1
Accumulation of the technical research achievements in terms of safety, serviceability and durability of the bridges Lessons learned from the recent earthquake, the durability
related damages of existing bridges Review of the damage estimation by the upcoming great
earthquakes such as Tokai, Tonankai, and Nankai earthquake
The 2002 Specifications Introduction of the performance-based design concept Improvement of the durability to design the sustainable bridges
Background of Revision of Japanese Design Specifications for Highway Bridge
The 2012 Specifications 2
Improvement of the requirements for easy and secure maintenance Revision of design earthquake ground motions for
interplate-type earthquake (Level 2 Type I earthquake) Introduction or improvement of specifications based on
recent research achievements • Introduction of integral abutment bridge • Improvement of minimum thickness of steel deck
plate to enhanced fatigue durability etc…
Significant Points of the 2012 Specifications
3
The Number of Road Bridges Constructed in Past Years (2011)
*Bridge length is 15m or more
Reference : Technical Note of NILIM, No.645,July 2011 4
0
30,000
60,000
90,000
120,000
150,000
180,000
0
1,000
2,000
3,000
4,000
5,000
6,000
Total N
um
ber o
f Brige
sN
um
ber of B
ridg
es
Construction Year
Others
Mix
Timber
Masonry
PC
RC
Steel
Total
50 years old or older
40 years or older
30 years or older
Damage of bearings for water leakage around end of girders
Damage of expansion joint
Fundamental Principal of Maintenance
5
Background Performance of bridges has changed by applying for
various factors such as live load, seismic, environmental effects in their service period. To perceive change of bridge condition by bridge
inspection is important to sustain the bridges for a long time. Most of existing bridges are difficult to inspect because
they were designed without a view to inspecting.
Fundamental Principal of Maintenance
6
2012 Specifications Improve the requirements that structural systems which
maintenance is expected to be difficult and insecure should be avoided. Bridges should be designed in consideration of
maintenance methods such as periodic and emergency inspection, repair, retrofitted works easily and securely.
Fundamental Principal of Maintenance
7
Example of providing the walkway
Fundamental Principal of Maintenance
Example of strengthening of main girder in advance for temporary jack up
8
Background The occurrence of great interplate earthquakes near Japan has been highly anticipated.
Revision of Design Earthquake Ground Motion
2012 Specifications Type I of Level 2 earthquake motion (for Interplate earthquake) was revised based on new attenuation relationships.
Zone factors for Type I earthquake motion were revised. 9
Design Earthquake Ground Motion Level 1: highly probable to occur during service period Level 2: high intensity with less probability to occur during the service period <Type I> Ground motion by large-scale interplate earthquake in the subduction area <Type II> Ground motion by near-field shallow earthquake
10
Anticipated Interplate earthquake areas near Japan
Revision of Design Earthquake Ground Motion
11
Zone (Zone Factor)
Revision of Design Earthquake Ground Motion
Development of new zone factor map
12
Revised Design Acceleration Response Spectra Type I Type II Zone: A1
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
(Soil Profile Type III)
Previous(2002) Revised (2012)
13
Revised Design Acceleration Response Spectra Type I Type II Zone: B1 (Soil Profile Type III)
Previous(2002) Revised (2012)
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
Design Considerations of Tsunami Effects
Superstructures inundated and washed away following failure of bearing supports
Superstructures inundated but survived
14
Background Many bridges were washed away by extreme tsunami
Design Considerations of Tsunami Effects
2012 Specifications Local plan for disaster prevention shall be considered in planning of road network, structural planning and design of bridges
Recommendation For Prevention Securing of sufficient clearance for tsunami wave height For Mitigation Considerations in structural design to mitigate the tsunami-induced effect to bridges, and preparation of a recovery plan in advance
15
Static loading test to examine resistant capacity of bearing supports
Simulated tsunami bore
Bridge model
Flume test for bridge model to study response of bearing supports
Experimental works to study
Response of bearing supports under tsunami-induced force through 1/20- scaled flume test
Resistant capacity of bearing supports under tsunami-induced force through 1/2-scaled static loading test
Downstream Upstream
Hydraulic Jack
Experimental Approach to Study Behavior of Bearing Supports under Tsunami-induced Force
16
-20
0
20
40
60
80
100
10 15 20 25 30
p4
p5
p6
p7
p(kP
a)
t(sec)
p1 p2 p3 p4
p5 p10
p11 p12
p6 p7
p8 p9 flow
-20
0
20
40
60
80
100
10 15 20 25 30
p1
p2
p3
p(kP
a)
t(sec)
Flow pattern for 4-main girder bridge
p1-p3
p4-p7
Pressure unit converted to full scale
Observed Hydrodynamic Pressure
17
Introduction of Integral Abutment Bridges Background Maintenance related problems such as corrosion at the end of girder and bearing with most of existing bridges 2012 Specifications Introduced fundamental principal of design and construction of integral abutment bridges which systems are omitted the bearing and expansion joint
(a)Portal Frame Bridge (b)Integral Abutment Bridge
Superstructure
Abutment
Pile Foundation
Superstructure
Abutment
Single row Pile Foundation
Omitted Expansion joint Bearing
18
Damage of Pavement on the Crack
Improvement of Fatigue Durability of Steel Deck
Background Fatigue cracks to penetrate a deck in a weld of closed rib and deck plate have been increased in the existing steel slabs. 2012 Specifications Minimum thickness of deck plate where wheel load of heavy vehicle is always loaded is prescribed more than 16mm (previous: 12mm) in case of steel deck using closed rib.
19
デッキプレート
Ｕリブ
デッキプレート
Uリブ
溶接ビード
亀裂
亀裂
ルート部ルート部※
デッキプレートの板曲げ変形
Closed rib
Crack
Deck plate
Crack Deck plate
Closed rib
Root Weld bead Root
Bending deformation of deck plate
Summaries
The 2012 Design Specifications for Highway Bridges were revised about mainly;
• Designing the bridge with consideration of the maintenance and redundancy
• Revision of design ground motions for interplate-type earthquake
• Introduction or improvement of specifications based on recent research results
We continue to examine to introduce the load and
resistance factor design concept for next revision. T/C G initiates collaborative research program on tsunami
effects on bridge performance. 20
21
Thank you for your kind attention
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
Soil profile type
100
1000
0.1 10.2 0.5 2 5
300
5000
200
500
2000
700
3
3000
Natural period (s)
Standard Acceleration Response Spectra (Type I earthquake)
Previous(2002) Revised (2012)
Type II Type I Type III
