2002 & 2012 Specifications for Highway Bridges
1.

International trend in promoting performance-based codes to easetrade barriers (ISO2394 (1998))

2.

Flexible acceptance to innovative technologies in construction projects
to meet diversifying technical proposals

3.

Needs for durable and maintenance-friendly structures
Advent of Performance-based Specifications

1) From prescriptive to performance-based: Required performance criteria
were philosophically set out, as requested by ISO2394
2) Performances comes first and mandated. Standards are regarded as
acceptable solutions. Alternatives can be confirmed to see if thealternatives offer equivalent or greater performances than the standards.
3) Prescriptions for durability demands on fatigue in steel members, andchloride ingress in concrete members, durable RC deck slab design etc wereshown.
4) A maintenance planning and relevant countermeasures are required ininitial design.

Need to articulate more regarding performancerequirements and evaluation procedures-- 1996

Detailed
standards
and specs

2002

2012

Conceptual / qualitative
Performancerequirements

Conceptual / qualitative
Performancerequirements

followed byfollowed by

Detailed
standards andspecs

Detailed
standards andspecs• To accept professional
ideas andinthe
structuraltypes, andThe structure
willproposal
remain in
next version,
modules, and materials --- Performance requirements have to beshown for competent agency to check their proposals.
• Detailed standards and specs are also necessary for competentagency to check their proposal by comparison in terms ofreliability

e.g. Hierarchy of the Specifications
Design Principles

Importance, Loads, Design
Ground Motions, Limit Statesof Bridges,
Principles of Performance
Verification
Detailed Performance Verification
Evaluation of Limit State of Members;

RC and Steel Columns,Foundations, Bearings, and Superstructures,Isolation Design; Unseating Prevention
Systems

Requirements(Mandatory andunaltered)

Acceptable Solutions(Can use othermethods afteran AppropriateVerification)

e.g. Hierarchy in Each Article
Concrete bridges --- Chapter 4 Details
Article 4.4.1 Cover depths
1.Cover depths shall be deeper than those shown in Table-4.4.1.
2.Cover depths also shall be larger than the diameter of reinforcement bars.
Types of members Deck slabs, parapet walls, slab
bridges shorter than 10m
Minimum depths

30mmGirders
Factory-madeprecast girders
25mmOthers
35mm

Concrete bridges --- Chapter 6 Details
Article 6.6.1 Cover depths
1.Cover depths shall be designed to secure bonds between concrete andreinforcement, prevent from corrosion of reinforcement, and make reinforcement
insensitive to fire. <<Performance criterion>>
2. Article 1 is satisfied when cover depths are given larger than the values specified
in Table-6.6.1 and the diameter of reinforcement. <<Acceptable solutions>>

Sharing problems• Fast constructione.g.
– Urban Areas• Maintenance friendly design5Maintenance-friendly structures
Frequency of earthquakes over M6(yr1999-2008)

Fatalities in recent large quakes
Japan 212(20.8%)

Other areas 806(79.2%)
Reference;
White Paper on Disaster Management

Mo/YrName

M

Sept 2003 2003 Tokachi-Oki

M8.0

Oct 2004

2004 Niigataken-Chuetsu

M6.8

Mar 2005

Hukuokaken-Seihouoki

M7.0

Mar 20072007 Notohanto

M6.9

July 2007

2007 NiigatakenChuetsuoki

M6.8

June 2008

2008 Iwate-Miyagi
Nairiku

M7.2

Source;Japan Meteorological Agency

www.jma.go.jp/

Bridge Scour

Typhoon No.9, Sep 2007
Source;http://www.nikkei.co.jp/news/main/im20070
907SSXKF007807092007.html

Severe cold to tropical hot weather
Not only thermal effects but also humidity and chloride
conditions are severe to the durability of bridges.

8

A further protection is required for bridges built on
the shorelineMajor disress(A1)

Fatigue fracture at
welding parts of U-rib anddeck plate(A2)

Fatigue fracture in a steel main girder,
Yamazoe Bridge, R25, constructed in 1971.

(B)

Anatomic survey for Kuretsubo
overpass, R7, constructed in 1965, that
suffered from salt attack.

(C)

ASR

10