No. 45 August 2015

STEEL CONSTRUCTIONTODAY & TOMORROW

http://www.jisf.or.jp/en/activity/sctt/index.html【 k o u 】
“構 (kou)” in Japanese, or structure in English

The usefulness of steel structures is growing in theconstruction of bridge and other civil engineering structures.
This issue, No. 45, covers the research attainments
presented at the 19th Symposium on Research on
Civil Engineering Steel Structures with a main theme of“Towards Stronger, Longer-lasting Steel Bridges.”

Special issue: 19th Symposium on
Research on Civil Engineering Steel Structures
1 Towards Stronger, Longer-lasting Steel Bridges Conducive
to Building National Resilience and Promoting Large-scale
Retrofitting of Existing Bridges

2 Current State and Large-scale
Renewal of Metropolitan
Expressway

5 Rational Performance

Evaluation and Strength
Design for Steel Bridges

Published Jointly by

The Japan Iron and Steel Federation

9 Fatigue Characteristics of Weld Joints Employing SBHS
12 Maintenance of Weathering
Steel Bridges

15 “Building National Resilience”

Initiative and Future Directions

Japanese Society of Steel Construction

Back cover JISF Operations

Special Issue
19th Symposium on Research on Civil Engineering Steel Structure

Towards Stronger, Longer-lasting Steel
Bridges Conducive to Building National
Resilience and Promoting Large-scale
Retrofitting of Existing Bridges
The Japan Iron and Steel Federation (JISF)
held its 19th Symposium on Research on
Civil Engineering Steel Structures on March
10, 2015 in Tokyo. In 1995, JISF established a “subsidy system for steel-structure
research and training” and since then has
provided subsidies to researchers working
in the field of steel structures. The symposium has been held every year with the aimof publicizing the results of research supported by the subsidy system while at thesame time promoting wider applications ofsteel structures.
As a link related to the research activities promoted by the subsidy system, theresearch promotion organization was established in 2013 and 2014-ResearchCommittee on Improvement of Structures
and Durability of Steel Bridges and three affiliated ad-hoc committees, Working Groupon Structures and Design Innovations of
Steel Bridges, Working Group on Fatigue
Strength of Steel Bridges and Working
Group on Maintenance of Weathering Steel
Bridges.
In recent years, the importance of technology that enhances the overall excellenceof steel bridges in terms of cost, performance and quality has grown. Meanwhile,another bridge performance factor that is
gaining importance is minimization of lifecycle costs (LCC), such as mitigation ofmaintenance costs and prolonging service
life. In order to meet such requirements, theResearch Committee extensively promotes
related research activities and organizes thediverse attainments that are derived fromthese activities.
At this year’s 19th Symposium on Research on Civil Engineering Steel Structures, the attainments of this research werereported and related lectures were delivered
to the approximately 380 engineers and researchers who attended. The titles of the lec-

1 Steel Construction Today & Tomorrow August 2015

tures and reports and the names of the lecturers at the 19th symposium are shown in
the table below.
This issue, No. 45, of Steel Construction
Today & Tomorrow is published as a special

issue spotlighting the symposium; an outline of the lectures and reports delivered at
the symposium is introduced in the following pages.
￭

A List of Lectures and Reports of Research Attainments Presented at the
19th Symposium on Research on Civil Engineering Steel Structures
Keynote lecture:
Current State and Large-scale Renewalof Metropolitan Expressway
Report of research attainments:(1) Rational Performance Evaluation andStrength Design for Steel Bridges(2) Fatigue Characteristics of Weld Joints
Employing SBHS
(3) Maintenance of Weathering Steel Bridges
Special lecture:“Building National Resilience” Initiativeand Future Directions

JISF held its 19th Symposium on
Research on Civil Engineering
Steel Structures in March 2015.

Kenichi Ando
Senior Executive Officer, Metropolitan
Expressway Company Limited

Yoshiaki Okui
Professor, Saitama University
Kazuo Tateishi
Professor, Nagoya University
Eiki Yamaguchi
Professor, Kyushu Institute of Technology

Satoshi Fujii
Professor, Kyoto University; Special
Adviser to the Cabinet, Cabinet Secretariat

Keynote Lecture

Current State and Large-scale Renewalof Metropolitan Expressway

Kenichi Ando: After graduating from the School ofEngineering, Waseda University, he entered Metropolitan Expressway Public Corporation in 1974. After serving as director of Planning and Environmental

by Kenichi Ando
Senior Executive Officer
Metropolitan Expressway Company Limited
Outline of the Metropolitan Expressway Network
About 50 years have passed since the opening of Metropolitan Expressway, a networkof arterial expressways linking metropolitan
Tokyo and its surrounding areas. The firstsection of the expressway, extending 4.5 km
between Kyobashi and Shibaura in downtown Tokyo, opened in December 1962 (Fig.
1). The daily traffic volume at that time wasDept. and Construction Dept. and director general ofTokyo Construction Bureau, he assumed his current
post as senior executive officer in 2013.

11,000 vehicles, and the toll for ordinary vehicles was ￥100 (￥50 for the first year ofoperation).
Most of Japan’s roads in the 1950s were
unpaved and turned to mud when rain fell,
sometimes requiring vehicles to be pushed
through the mire. This situation demonstrated that road improvements in Japan werelong overdue. To remedy this, two systems
were initiated-a toll road system (1952) inFig. 1 Network of Metropolitan Expressway
Joban Expressway

Tohoku Expressway
Yono

Saitama Minuma(Saitama Pref.)Kawaguchi JCT

Tokyo Gaikan Expressway
Misato JCT

Kanetsu Expressway
Bijogi JCT(Chiba Pref.)KohokuJCT
Itabashi JCT
Kumano-cho JCT(Tokyo)Horikiri JCT

Kosuge JCT

Iriya
Yagochi
Nishi-Shinjuku JCT

Chuo
Expressway

HakozakiJCT

OhashiJCT

Takaido

Yoga

ShibauraJCT
Togoshi

Tomei
Expressway

Showajima
JCT
Daisan Keihin Road
DaishiJCT
Fujimi

Shimoyamotocho

Tatsumi KasaiJCTJCTKeiyo Road
Koya
Higashi-Kanto
Expressway

Shinonome JCT
AriakeJCT

Oi JCT
Tokai JCTFirst opened route ofMetropolitan Expressways(Kyobashi~Shibaura)

Haneda Airport

Kawasaki-Ukishima JCT(Kanagawa Pref.)Mitsuzawa

Yokohama Shindo

Kawamuko-choTokyo Wan Aqua Line

Namamugi
JCT
Kinko
JCT

Daikoku JCT

KaribaIshikawa-cho JCT

Yokohama
Yokosuka Road

NamikiJCT

Honmoku Futo JCT

Route in service: 310.7 km
Route under construction: 18.9 km

which drivers were charged a toll fee to cover the cost of road construction and a revenue
source earmarked for roads (1953).
The motorization of Japan progressed
rapidly from around 1955 and brought with
it deteriorating highway traffic conditions.
In response, it was necessary to construct theexpressway for exclusive use with automobiles. Then, it was decided that the networkof expressways in metropolitan Tokyo be improved and, in June 1959, Metropolitan Expressway Public Corporation (former Metropolitan Expressway Company Limited) wasestablished. In May of the same year, the International Olympic Committee selected Tokyo to host the 1964 Olympic Games.
Today, the daily traffic volume of Metropolitan Expressway is about 950,000 vehicles. The ratio of the total length of Metropolitan Expressway to that of national andTokyo metropolitan roads in 23 wards isbarely 15%. However, the ratio of Metropolitan Expressway is about 36% in terms of vehicle-kilometers and about 28% in terms of
freight traffic volume-or more than twice
all national and metropolitan roads in Tokyoin terms of vehicle-kilometers and freighttraffic volume. This means that the Metropolitan Expressway is indispensable for the
daily routines of the residents of Tokyo andits surrounding areas.
Network Development of and Improvement Plan for Metropolitan Expressway
On May 7, 2015, the final section of the Central Circular Route (Bay Shore Route~Route3 Shibuya Line) was opened to traffic, extending the total length of routes in operationin the Metropolitan Expressway network to
310.7 km. Another 18.9-km route is currently
under construction and, when completed, it
will extend the total to about 330 km.
The Central Circular Route required morethan a half century to go from initial route in-August 2015 Steel Construction Today & Tomorrow 2

vestigation to completion. The route’s 18.2km Yamate Tunnel is the longest road tunnel
in Japan and it was built utilizing a variety ofadvanced construction technologies, among
which were a method to expand shield tunnel width underground (Fig. 2) and a cutting
shield tunnel construction method that could
integrate two or more shields underground.
Prior to that, ordinary roads were open-cut,
traffic had to be closed and lanes regulated, and branch sections and exit/entry ramps
were constructed by means of the open-cut
method. However, use of these two underground methods has made it possible to suppress the effects on ordinary roads to a minimum.
The Ohashi Junction is a typical example of a junction constructed within a narrow space. In this junction structure, the lower section which begins about 35 m below
Fig. 2 Underground Shield Tunnel
Width Expansion Technology

ground connects with the upper section which
ends about 35 m above ground. In the junction that connects the difference of elevationof about 70 m, the maximum grade was designated at 7%, and thus a 1,000-m distance
was necessary for the vehicle to climb the 70m difference of elevation. One effective solution that was devised to meet the requirement
was to provide a 400-m track in order for thevehicle to reach the junction’s upper section
through 2.5 rotation running of track. Photo 1
depicts the Ohashi Junction.
As an environmental measure, a large
cap-shaped structure was built over the junction and now serves as a park in Meguro
Ward (Photo 1). Further, in order to meet therequest of residents displaced by the junction
to return to the site, the Tokyo Metropolitan
Government built two high-rise buildings
nearby as an urban redevelopment project. The displaced residents could move into these buildings after the junction was completed.
We believe that the Ohashi Junction project will serve as a model case for future road
construction and urban development. The
project has received the Good Design Award,
a prominent award given for excellent design
performance, as well as many other publicrecognitions.
Large-scale Renewal and Repair ofMetropolitan Expressway
The structures of Metropolitan Expressway
network are getting old. Of the network’s to-

Tunnel in service

tal length of about 310 km, around 30% of
the expressway structures have been in service more than 40 years and about 50% havebeen in service 30 years (Fig. 3). Further,
the tunnels and viaducts that require minutemaintenance account for about 95% of all expressway structures. On top of this, large-vehicle traffic volume is high.
Given this situation, the Metropolitan
Expressway Company established the Research Committee Tasked with Reviewing
Approaches to Large-scale Renewal of Metropolitan Expressway Structures (chaired byProfessor Shiro Wakui of Tokyo City University). Based on the proposals submitted
by this committee in January 2013, the company extended its deliberations and publicly announced the renewal plan in December 2013. Five sections of the expressway
were determined to be in need of renewal and reconstruction: Higashi-Shinagawa
Wharf~Samezu Landfill section, Daishibashi
section, Ginza~Shintomicho canal section,
Takebashi (incl. Nihonbashi)~Edobashi section, and Ikejiri~Sangenjaya section (Fig. 4).
The renewal cost will amount to about ￥380
billion. Further, large-scale repairs are also planned for the 55-km section at a costof about ￥250 billion. The total cost for theplanned renewal and repair projects will be
about ￥630 billion.
When the Tokyo OlympicGames were
held in 1964, a 30-km section of what is today’s expressway network was in service.
That route is now in need of renewal. (Fig. 5)

Fig. 3 Lapse of Years since Opening of Expressway Lines (as ofApril 2015)

Undergroundexpanded section

Total
length50 years or more
40~49 years
30~39 years
20~29 years
10~19 years
9 years or less

Photo 1 Full view of Ohashi Junction

3 Steel Construction Today & Tomorrow August 2015

Inner Circular Route, Haneda Line, Shinjuku Line
Meguro Line, Yokohane Line, Shibuya Line
Fukagawa Line, Mitsuzawa Line, Bay Shore Line (Tokyo~Chiba)
Kariba Line, Daiba Line, Kawaguchi Line
Omiya Line, Kawasaki Line, Bay Shore Line (Kanagawa)Harumi Line, Central Circular RouteOf the sections slated for renewal, procedures for concluding the construction contract are underway for the Higashi-Shinagawa Wharf~Samezu Landfill section. Thissection is to be rebuilt to a viaduct structure
higher from the sea level in order to improve
durability and maintenance performance.
A viaduct structure equipped with permanent scaffolding is being examined with theaim of allowing constant inspection work to

be made. The current daily traffic volume ofthis section is about 80,000 vehicles, whichmakes traffic closures for renewal work unfeasible. Therefore, a new two-lane detour
will be constructed for use during the renewal work. (Fig. 6)
Renewal of the Higashi-Shinagawa
Wharf~Samezu Landfill section of the Route1 Haneda Line will be underway during the2020 Tokyo Olympic Games. In order to se-

Fig. 4 Expressway Sections subject to Large-scale Renewal
Takebashi~
Edobashi section

cure safe and smooth vehicle traffic duringthat period, Metropolitan Expressway Company is studying a construction procedure inwhich a temporary 2-lane detour and 2 laneson the new viaduct will be put into service sothat the damaged section need not be used atleast (Fig. 6). Steady efforts are being made tostart this renewal work within FY2015.
￭

Fig. 5 Expressway Sections Opened to Traffic in Tokyo
Olympic Games 1964 and Location of Large-scale
Renewal Sections
Takebashi~Edobashi section (river)

National Stadium

Athletes’ dormitories
Ginza~Shintomicho section (river)Ikejiri-Sangenjaya section (road)
Ikejiri-Sangenjaya section

Higashi-Shinagawa Wharf~
Samezu Landﬁll section (waterway)

Komazawa Olympic Park
Ginza~Shintomicho section
Higashi-Shinagawa Wharf~
Samezu Landﬁll section

Section in service in Tokyo
Olympic Games 1964
Large-scale renewal section

Daishibashi section

Daishibashi section (river)

Haneda Airport

Fig. 6 Image of Renewal of Higashi-Shinagawa~Samezu Landfill Section

Present state

Temporary
detourAfter large-scale renewal (image)Detour under construction (image)

August 2015 Steel Construction Today & Tomorrow 4

Report of Research Attainments (1)Rational Performance Evaluation andStrength Design for Steel Bridges
Yoshiaki Okui: After finishing the master program of
Graduate School of Science and Engineering, Saitama
University in 1983, he entered Kawasaki Heavy Industries, Ltd. in 1985. He assumed a post as an assistant at
the Faculty of Engineering, Saitama University in 1989

by Yoshiaki Okui
Professor, Saitama University

Fig. 1 Analytical Model for Non-stiffened Compression Plate (Fourside Simple Support)

5 Steel Construction Today & Tomorrow August 2015

neering, Saitama University in 2009.

Rational Load-bearing Capacity of
SBHS steels are not included in the SpecifiCompression Plates
cations for Highway Bridges.
The compression plate strength design equa- • The practice of finding safety factors based ontion was reexamined2). Three major factors
reliability design theory is the currently prerequiring reexamination are cited as follows:
vailing trend in the preparation of advancedThe
regulation
for
stan•
dard load-bearing capac- Fig. 2 Probability Density Function of Initial Deflection
ity that is found in theUsed for Monte Carlo Simulations
current Specifications for
Relative frequancy dist.of intial deﬂection
Highway Bridges1) wasprescribed based on theelastic buckling theory
and data derived from experiments conducted in
the 1970s; also, most of
the data was based on experiments conducted on
approximately 10 mmthick plates. However, themaximum plate thickness
in current steel bridge
construction has grown
to 100 mm, which has
led to the increased useof heavy-gauge plates.
While
SBHS500 and•
Fig. 3 Comparison between Monte Carlo Simulation
SBHS700- Steels
Results (μ=average value, σ=standard deviafor Bridge High Pertion) and Load-bearing Curve in Specifications
formance Structuresfor Highway Bridges (JSHB)(SBHS)-were standardized in JIS in 2008,
Relative frequancy

With the aim of further enhancing the competitiveness of steel bridges, the Working
Group on Structures and Design Innovationsof Steel Bridges, established in the ResearchCommittee on Improvement of Structures
and Durability of Steel Bridges, the JapaneseSociety of Steel Construction, conductedanalyses and experiments to collect evidence
for use both in examining new bridge design
standards and in revising current bridge design standards.
The specific items examined were as follows:• Rational load-bearing capacity of compression plates
Bendingand shear strength of steel I girders•
Performance-based
design methods and ad•vanced analytical approaches• Rational friction joining of high-strength bolts• Measurement of residual stress in SBHS (Steels
for Bridge High Performance Structures) andthe effect of residual stress on the strengthof steel members
The following outlines the results for fourof the items examined, excluding the final
item.

and his current position as a professor, School of Engi-

design standards around the world. To copewith this trend, it has become necessary toobtain probability data such as mean values
and standard deviations of critical strengths.
In order to meet such requirements, finite
element analysis and Monte Carlo simulation
were employed in this study. Fig. 1 shows theanalytical model for non-stiffened compression plates (4-side simple support). The modeof initial out-of-plane displacement was assumed to be a sine waveform, and the residual stress was assumed to be the residual stress distribution configuration as shownin the figure. In the Monte Carlo simulation,
the maximum value for initial deflection W0
and the compressive residual stress σre are assumed to be random variables, and, they are

randomly generated according to the probability density functions shown in Fig. 2 as an
example. In the trial runs of the Monte Carlosimulation, because of the difficulty of conducting finite element analysis in every simulation, the response surface method was adopted to reduce the calculation time.
Fig. 3 shows the comparison between theMonte Carlo simulation results for the fourside simple supported stiffening compression
plate and the load-bearing capacity curve inSpecifications for Highway Bridges (JSHB),
together with the existing study results3),4). A
similar investigation was made for projection
panels5). It is possible to rationally determine
the partial safety factor by using these examination results. To that end, it is expected that

Fig. 4 Bending Test Specimens Using SBHS (Steels for
Bridge High Performance Structures)(a) Elevation(b) Cross section

Table 1 Dimensions of Test Specimens
Name ofspecimen

Steel grade of
specimen

bf

tf

Dw

tw

d0

L

(mm)

(mm)

(mm)

(mm)

(mm)

(mm)

SBHS500M

SBHS500

250.4

12.2

900.8

9.0

1198

6199

SBHS700M

SBHS700

250.2

12.6

901.4

9.0

1195

7788

these examination results will be incorporated in the next revision of Specifications for
Highway Bridges.
Rational Equation to Calculate I-girder Strength
Load-bearing capacity tests were conducted for I-girders employing Steels for Bridge
High Performance Structures (SBHS500
and SBHS700) in order to verify the validity of using SBHS in steel bridge girders andthe validity of the design equation for SBHS steel girders. Fig. 4 shows the approximate configurations of the specimens usedin the bending tests. Loading was applied bymeans of 4-point bending, and the panel located at the center of the specimen was usedas the test panel. Table 1 shows the dimensions of the test specimens used in the bending test. Testing was conducted on two specimens named SBHS500M and SBHS700M.
Fig. 5 shows the load-deflection curve
obtained in the tests. Pn in the figure shows
the load for nominal design bending strength
specified in AASHTO LRFD, and Py the load
for the flange yield bending moment in thetests. It was confirmed in the tests that thebending strength for both SBHS500M andSBHS700M specimens surpasses the nominal design bending strength specified in
AASHTO LRFD. While the application
range of steel products in AASHTO LRFD
is for steel products within a yield strength2of 485 N/mm , both SBHS500 and SBHS700
are out of the application range in AASHTO LRFD. However, it was verified that thebending strength evaluation equation that isdeveloped for conventional steel can be applied to SBHS500 and SBHS700.

Fig. 5 Results of Bending Tests (Load-Deflection Curve)(a) SBHS500M(b) SBHS700M

August 2015 Steel Construction Today & Tomorrow 6

Photo 1 shows the SBHS700M specimen
after loading. The type of collapse was of thelocal buckling of the flange.
Rational Bridge Design Employing
Advanced Analytical Approaches
In steel bridge design, it is necessary to appropriately evaluate the stress occurring in
the members. In conventional design, thesectional force of the members and the stress
distribution inside the members are calculated by means of frame structure analysis
based on beam theory. However, regulationof the current design environment allows forthe relatively easy application of the finite element method and other advanced structural analytical methods; accordingly, the rational bridge design method was studied using
these advanced analytical approaches.
The following introduces the results ofstudies directed to the corner sections ofbeam-column connection shown in Fig. 6.
As regards the stress distribution in the corner sections, it is known that the stress distribution found based on beam theory differs
greatly from the actual stress distribution due

Photo 1 Deformation of SBHS700M specimen after loading

Fig. 6 Numerical Model of Beam-Column Connection of
Bridge Pier

7 Steel Construction Today & Tomorrow August 2015

to the shear lag effect.
In this situation, comparative examinations of stress distribution were made using
three analytical methods: (a) the finite element method using a shell element, (b) the
analytical method proposed by Okumura andIshizawa, and (c) the finite element method
using a constant shear flow panel.
The method proposed by Okumura andIshizawa examines the shear lag effect by useof the beam theory and the stress concentration factor, and has seen wide practical application in bridge design in Japan. Meanwhile, the constant shear flow panel method
is an analytical approach that is composed ofa plate element that resists only shear stressand a beam element that bears only verticalstress accompanied by bending along the outer periphery of the plate element. Comparedto the finite element method with a shell element, the constant shear flow panel method offers the practical advantage of needing
fewer calculations.
Fig. 7 shows a comparison of normal
stress distribution in the beam lower flange
among the various methods. In the figure, thered line shows the analytical results obtainedusing the constant shear flow panel method,
the blue line shows the results obtained byusing the shell method, the black line denotes
the nominal stress obtained by using beam
theory, and the Δ mark stands for the stressjust above the web that was obtained by using the method proposed by Okumura andIshizawa.

Fig. 7 Comparison of Stress Distributions at Corner Section of Lower Flange

While it is necessary, in the finite element
method using shell elements, to finely divide
the elements so that they are 25 mm or under in size in order to obtain the stress distribution with a certain level of accuracy; in theanalytical method using a constant shear flow
panel, it is possible to make a highly accurate analysis even when using comparatively
rough element divisions as shown in Fig. 6.
Rational High-strength Bolt Friction
Joining
In recent bridge construction, the size andplate thickness of the structural members are
increasing; thus the number of rows of highstrength bolts increases steadily for member
joints. However, there is insufficient clarity
regarding the effect that surface treatments,
greater thickness of steel plates, and the multiple-row arrangement of bolts have on the loadcarrying capacity of high-strength bolt friction
joints. Therefore, experimental and analyticalexaminations were conducted to discover theextent to which the slip factor is effected by
the heavier plate thickness of friction joints
using high-strength bolts with contact surfaces coated with zinc-rich paint and by the multiple-row arrangement of high-strength bolts.
Photo 2 shows the experiment that was used
to verify the sliding strength of the friction
joints. The effect that the heavier plate thickness of friction joints and the multiple-row arrangement of high-strength bolts have on reducing the slip factor was examined by meansof the experiment shown in the photo and by finite-element analysis (refer to Fig. 8) that takes
frictional slippage into account.
￭
References
1) Japan Road Association. Specifications for
Highway Bridges – part II. Steel Bridges, 2002.
2) Duc, D.V., Okui, Y., Hagiwara, K., Nagai, M.,
Probabilistic distribution of plate bucklingstrength for normal and bridge high-performance steels, International Journal of Steel
Structures, pp. 557-567, Vol. 13, No. 3, 2013.
3) Fukumoto, Y. and Itoh, Y., Basic compressive
strength of steel plates from test data, Proc.
of JSCE, No. 334/I-1, pp. 129-139, 1984.
4) Usami, T., Ge, H., Strength prediction of thinwalled plate assemblies, Journal of StructuralEngineering, Vol. 42A, pp. 171-178, 1996.
5) Komuro, M., Okui, Y., Nozaka, K., Niyashita T., Nogami, K., Nagai, M., Numerical
study on ultimate strength of compressive
flange considering statistical data for distributions of initial displacement and residual stress, Journal of Structural Engineering,Vol. 60A, pp. 80-93, 2014

Photo 2 Slip strength test for multiple-row high-strength bolt friction joint with heavier plate thickness

Fig. 8 Finite Element Analysis Model of Bolt Joints

August 2015 Steel Construction Today & Tomorrow 8

Report of research attainments (2)Fatigue Characteristics of Weld Joints
Employing SBHS
Kazuo Tateishi: After graduating from the Faculty of Engineering, Tokyo Institute of Technology, he entered East Japan Railway Company. He then served as an associate professor of Tokyo Institute of Technology and University ofTokyo. He became a professor of the School of Engineeringby Kazuo Tateishi
Professor, Graduate School of Nagoya University
SBHS (Steels for Bridge High Performance
Structures) are high yield-point steel plates
for bridge construction that were specified in
JIS in 2008. SBHS feature a high yield point
and tensile strength (Table 1), and further because of their high weldability, preheating
can be eliminated or preheating temperatures
can be lowered. To that end, their application allows cost reductions in various aspectsof bridge construction: fabrication, transportand erection.
On the other hand, in cases when SBHS
are applied, there is a relatively large increasein the live-load stress because of the thinplate thickness of the members, thus leading
to concerns about fatigue problems. However, as the fatigue characteristics of weld joints
employing SBHS have yet to be satisfactori-in 2003 and assumed his current position as a professor of
Graduate School of Engineering, Nagoya University in 2010.

ly clarified, almost no accumulated data are
available, particularly for SBHS 700. Therefore, we decided to conduct a basic study ofthe fatigue characteristics of weld joints employing SBHS.
Evaluation of Fatigue Crack GrowthCharacteristics
The crack growth characteristics of SBHS
were investigated by means of a fatigue crack
growth test for compact tension test specimens. The crack growth test was conductedconforming to ASTM.
Fig. 1 shows the relation between thecrack growth rate and the stress intensity factor range ΔK of SBHS500 and SBHS700 thatwas obtained from the test. The curve in the
figure shows the average values and the de-Table 1 Mechanical Properties of SBHS (Steels for Bridge High Performance Structures)
Grade

Plate thickness(mm)Yield point or proof strength(N/mm2)Tensile strength(N/mm2)

SBHS500
SBHS500W

6

t

100

500 or more

570~720

SBHS700
SBHS700W

6t

75

700 or more

780~930

Fig. 1 Test Results for Crack Growth

Average design curb of JSSC
Safest design curb of JSSC

9 Steel Construction Today & Tomorrow August 2015

Average design curb of JSSC
Safest design curb of JSSC

viation range of conventional steel. As thetest results for SBHS fall within the range ofdeviation of the test results for conventional steel, it can be said that the crack growth
characteristics of SBHS are nearly identicalto those of conventional steel.
Measurement of Residual Weld
StressUsing the cutting method and the x-ray diffraction method, measurements were madeof the residual stress that occurs at a point 2
mm from the toe of out-of-plane gusset weld
joints of small-size test specimens (SBHS500
and SBHS700, shown in Fig. 2) and of a girder test specimen (SBHS700, shown in Fig. 3).
Fig. 4 shows the measured results. In thesmall test specimens of both SBHS500 and
SBHS700, the tension residual stress occurred that was equivalent to about 50~70%of the yield point. In the girder test specimen, the tension residual stress occurred thatwas equivalent to about 80~90% of the yield
point, which was a higher value than that of
the small-size test specimens. The reason forthe higher value is thought to be due to thedifference in the restraint level in the weldingof both specimens.
Fatigue Tests for Small-size Test
Specimens
Fatigue tests were conducted on test specimens of small-size out-of-plane gusset weld
joints prepared using SBHS. The configuration of the test specimens was as shown in
Fig. 2. The stress ratio was set at about 0.
Fig. 5 shows the fatigue test results. The
figure also shows the results of previous fatigue tests1) conducted on out-of-plane gusset weld joints prepared using conventional
steel and SBHS. The current test results show
almost no difference in fatigue strength depending on the grade of the steel materials.
The test results for the stress range of SBHS
out-of-plane gusset as-welded joints are dis-tributed in the vicinity of JSSC (Japanese Society of Steel Construction) Class E design
curve, and thus satisfy the fatigue design
guidelines currently in use.
Fatigue Tests for Girder Test Specimens
Fatigue tests were conducted on a large-size
girder test specimen having a span of 6,000
mm shown in Fig. 3. The steel grade used forthe girder specimen was SBHS700. Part of
the welding toes were finished by means ofgrinding or peening.
Fig. 6 shows the fatigue test results. The

number of testing cycles needed to reachthe stage when a crack has grown to 10 mm(40~50 mm in entire length) from the weld
bead to the base metal is indicated as the fatigue life. The figure also shows the existing
fatigue test results for the girder test specimens (however the testing cycle is shown fora crack length of 20~40 mm). As a result of
the test, the fatigue strength of the as-welded joints nearly satisfies the Class G requirements as specified by JSSC and is similar tothat of conventional steel. Because the test
was finished at a stage when no cracks had
yet emanated from the finished weld toe, dif-

Effect of Grinder Finish on Fatigue
Strength Improvement
The fatigue strength of steel materials improves as their static strength increases. It is

Fig. 4 Measurement Results for Residual Stress
Residual stress (N/mm2)

Fig. 2 Weld Joint Test Specimens (SBHS500 and
SBHS700)

ferences in fatigue strength depending on themethod of toe finishing could not be confirmed. However, the fatigue strength of thefinished toes obtained from the test results
surpasses Class E specifications, and the fatigue strength of the finished weld joint is improved by two classes or more over that of
non-finished (as-welded) weld joints in ClassG.

GussetWeld
X-ray residual stressmeasurement method
Cutting method

Joint specimen(SBHS500)

Fig. 3 Girder Test Specimen (SBHS700)(Equally bent section)

Nominal stressrange
Toe finishing

X-ray residual stressmeasurement method
Cutting method

Joint specimen(SBHS700)

Distance from center of width y (mm)Residual stress (N/mm2)(unit: mm)

Residual stress (N/mm2)

Distance from center of width y (mm)Girder specimen(SBHS700)

Distance from center of width y (mm)Fig. 5 Fatigue Test Results for Small-size Weld
Joint Specimens(Shimanuki et al)(Shimanuki et al)
Results in other past studies

Fig. 6 Fatigue Test Results for Girder Weld Joint
Specimens

test specimen
As-welded (equally bent section)
As-welded (shear section)
Finished (equally bent section)
test specimen
As-welded (equally bent section)
Finished (equally bent section)

Girder specimen data in past studies

August 2015 Steel Construction Today & Tomorrow 10

possible that the fatigue strength of steel materials is improved by grinder-finishing thewelding toe. To study this, out-of-plane gusset weld joint specimens were prepared andgrinder-finished under identical finishingconditions. An examination was then madeof the dependency of steel material strengthon improvements in fatigue strength.
The steel grades applied were SM490,
SBHS700 and SBHS500. Fig. 7 shows theconfiguration of the out-of-plane gusset test
specimens. In gusset welding, full penetration welding was applied to a 50-mm section
from the box weld zone in order to preventthe occurrence of fatigue cracks from theweld root section.
Grinder-finishing of toes was provided
for the test specimens of the respective steel
grades with a target grinding radius of 3 mmor more and a grinding depth of 0.5 mm. Fig.
8 shows the results of measurements of theradius and angle of the toe section (or finished toe section), and Fig. 9 the distributionof the grinding depth. It can be understoodfrom the figures that the grinding treatment
for the respective specimens was nearly identical in configuration.

The fatigue tests were conducted on thesetest specimens under the condition of out-ofplane bending. The stress ratio was set at 0.1
or lower. In the as-welded specimens, all fatigue cracks occurred from the weld toe section of the main plate member; in the grinderfinished specimens of SM490 and SBHS500,
all cracks occurred from the grinder-finishedsection; and in specimens of SBHS700, allcracks occurred from the gusset-side toe section.
Fig. 10 shows the fatigue test results. Fatigue life is denoted as the number of testing
cycles required for a crack to grow 10 mmfrom the weld bead to the base metal. In the
as-welded specimens, there was no discernable difference in fatigue strength dependingon the grade of the steel materials, and it canbe confirmed that there is no dependency ofsteel product strength on the fatigue strengthof the weld joint. On the other hand, the fatigue strength of grinder-finished specimens
increases as the strength of the steel materials increases, and thus it is seen that the fatigue strength depends on the strength of thesteel materials.
Particularly in SBHS700 specimens, fa-

Fig. 7 Out-of-plane Gusset Test Specimens

tigue cracks did not occur in the grinder-finished section but instead were seen in thegusset-side toe section. The fatigue test thus
conducted shows grinder finishing greatly improve the fatigue strength of SBHS700
weld joints.
￭
Acknowledgement
The current research represents one aspect of
the activities of the Working Group on Fatigue Strength of Steel Bridges of the Research Committee on Improvement of Structures and Durability of Steel Bridges. We
offer thanks to those of the Japan Iron andSteel Federation and the Japanese Society of
Steel Construction who support our current
research activity.
Reference
1) H. Shimanuki, T. Mori and M. Tanaka: Effect of Steel Product Strength on Improvement of Fatigue Strength by Means of UIT,
Journal of Japan Society of Civil Engineers,
I-144, 2011

Fig. 9 Grinding Depth
60

(

)

300

12

Frequency (%)

50
40
30
20
10
0

300

0〜0.1

0.1〜0.2

0.2〜0.3

0.3〜0.4

0.4〜0.5

0.5〜0.6

0.6〜0.7

0.7〜

Grinder-finished depth (mm)Fig. 10 Fatigue Test Results for As-welded and Finished
Weld Joints

Toe radius (mm)Equivalent stress range (MPa)Fig. 8 Radiuses and Angles of Toe or Finished Sections

Number of cycles
Toe angle (°)

11 Steel Construction Today & Tomorrow August 2015

Report of Research Attainments (3)Maintenance of Weathering Steel Bridge
Eiki Yamaguchi: Graduating from the University ofTokyo with a bachelor’s degree in civil engineering,
he went abroad for further study and earned his Ph.D.
degree at Purdue University in 1987. After working in
Kyushu University and the University of Tokyo, he

by Eiki Yamaguchi
Professor, Kyushu Institute of Technology
It is crucial to prevent corrosion for steel
bridges to have a long life. Painting is effective to that end, but quite costly, amounting
to about 10% of the construction cost of a superstructure. Besides, repainting is required
during the service life of a bridge. The conventional steel bridge cannot be very competitive especially from a viewpoint of life cycle cost.
Weathering steel possesses a unique property of suppressing the development of corrosion by a layer of densely-formed fine ruston its own surface: the corrosion rate gradually reduces to the level that causes virtually no damage from an engineering viewpoint,
as the layer of the rust grows. Photo 1 shows
how the weathering steel bridge changes
with time. The painting is not required in the

joined Kyushu Institute of Technology and is Professor there since 2004.

weathering steel bridge, the cost of which canbe much lower than that of the conventional
steel bridge. The weathering steel bridge istherefore gaining popularity in recent years.
As the number of weathering steel bridges increases, however, the reports of unexpected
corrosion state is coming out.
In light of the current situation, the Working Group (WG) on Maintenance of Weathering Steel Bridges under the Research Committee on Improvement of Structures andDurability of Steel Bridges of the JapaneseSociety of Steel Construction was set up in
2012. The members of the group consist ofa wide range of engineers including practitioners, bridge owners and academics. WG
first reviewed the recent inspection results ofweathering steel bridges. At the same time,(a) Two months old(b) One year old(c) 17 years old(d) 22 years old

it prepared questionnaires for bridge owners
and bridge engineers as to the maintenance of
the weathering steel bridge. Based on the information thus obtained, WG worked on themaintenance issues of the weathering steel
bridge. The present article is to provide theoutline of these activities.
Performance of Weathering Steel
Bridge• Judgement
Since the weathering steel bridge may not
perform as expected, the performance is to
be inspected. To that end, a state of corrosion
is evaluated by classifying it into one of fivelevels. Brief description of the criteria for
the five levels are shown in Table 1. While
the performances of Levels 3 and higher are

Photo 1 Weathering steel bridge

August 2015 Steel Construction Today & Tomorrow 12

satisfactory, the corrosion states of Levels 1
and 2 are not expected from weathering steel
and need attention if found. For Level 2, frequent observation is recommended. Level 1
requires further investigation to determine
whether or not the bridge should be repaired.
Since the bridge is a large structure, astate of corrosion in a weathering steel bridge
is not necessarily uniform. It can vary from
portion to portion. In particular, a local corrosion state near the girder end is often foundquite different from the corrosion state in a
general portion.
The corrosion state is judged by conducting the so-called Scotch-tape test. In this test,
the Scotch tape is pressed against the weathering steel. An example of the test result isgiven in Fig. 1. Examining rust particles thus
taken, the corrosion state is classified into
one of the five levels given in Table 1.

Table 1 Criteria for Corrosion-State Level
Level

Description of rust particle

Rust thickness

5

Fine but non-uniform

Less than about 200μm

4Average size of about 1 mm ; fine and uniform

Less than about 400μm

3Average size of 1-5 mm

Less than about 400μm

2

Average size of 5-25 mm

Less than about 800μm

1

Formation of rust layer

Larger than about 800μm

Fig. 1 Scotch Tape Test

• Performance

The recent survey of Japan Bridge Association (JBA) reveals the performance of theweathering steel bridge. 86% of the inspected bridges are in good shape, carrying a corrosion state of Level 3 or higher, while theremaining bridges have a corrosion state ofLevel 1 or 2. An effort has been made to
identify the cause for the poor performance.
It turned out that 68% of those bridges withan unexpected state of corrosion had sufferedfrom water leakage and 32% were located close to another bridge or sloped natural
ground. The girder end is in a quite different situation: 31% of the bridges had girder
ends in a state of Level 1 or 2. About 80% of
those girder ends were found exposed to water leakage.
An expansion joint is one of the bridge
elements most susceptible to damage due
to traffic loads. The broken expansion joint
causes water leakage, exposing the girder end
to constant humidity. This accounts for theworse performance of the weathering steel at
the girder end.
The survey also shows that de-icing agent
increases the rate of poor performance of theweathering steel bridge by about 10%. Thisrate is the same at the general portion and thegirder end. It is also found that with the presence of de-icing agent, water leakage tends tohave a worse influence, accelerating the development of unexpected corrosion state.
Questionnaire Survey
The questionnaire survey was conducted so
as to extract issues to be solved in dealing
with weathering steel bridges. Some of the

13 Steel Construction Today & Tomorrow August 2015

Dry gauze type accumulator

Exposure test piece
Photo 2 Survey setup for de-icing agent

Fig. 2 Deposition of De-Icing Agentcomments are given herein.
• There exist too many technical documents tostudy. They have to be combined and compiled, yielding an authorized document ofsome sort.
• There are structural details unique to weathering steel bridges. However, the effects ofsome of those details are not clear, making
it difficult to employ them in design.
• It is not an easy task to evaluate the performance of weathering steel. A good set ofsample photos of corrosion states is needed.
• It appears difficult to detect cracks inweathering steel.
1/3• of the local governments have experienced the repair of the weathering steel
bridge. Many of those bridges were painted. Steel plates were installed in somebridges for reinforcement. Since the surface of those steels were corroded rather
badly, they were not sure what would bea relevant base material control or adjustment. A manual for the repair of the weathering steel bridge is needed.

Fig. 3 Rust Particle(a) Maximum size of rust particle(b) Minimum size of rust particle

Influence of De-Icing Agent
Survey of the influence of de-icing agent on
nine weathering steel bridges that are different in volume of the agent consumption andtraffic volume began in December, 2014. The
locations of those bridges are far away fromthe coast, so that no influence of the air-born
salt is expected. A typical survey setup is
shown in Photo 2.
Although this is an ongoing project andnot much result has come out yet, some observations including those from the pre-investigation are available: the influence of de-icing
agent decreases rather rapidly in an exponential fashion, as one moves away from the siteof the use of de-icing agent; the influence ofthe de-icing agent lasts about two and a halfmonths even after the last use; the influenceof de-icing agent is found large on the exterior surface of the outmost girder; and theamount of the deposition of de-icing agent isvery large between closely-positioned parallel bridges. A result of the variation of de-icing-agent deposition is presented in Fig. 2.

Quantification of Criteria for Corrosion States
A corrosion state is the indication of the performance of weathering steel. The evaluationof the corrosion state is therefore important
for the maintenance of the weathering steel
bridge. In a current practice, the evaluation isdone by the criteria given in Table 1, which isbased on the external rust appearance. While
this practice is simple, it is quite difficult, if
not impossible, to ensure the objectivity ofthe evaluation result. The criteria had betterbe more quantified.
Improvement was tried by making use ofimage analysis. Specifically, Scotch tapeswith rust particles were analyzed and various
quantities that characterized the state of corrosion were obtained. The quantities include
the maximum size of a rust particle (Fig. 3(a)), the maximum value of the minimum
size of a rust particle (Fig. 3 (b)), the density of rust particles and so on. To this end,
27 pieces of Scotch tape with rust particles invarious states of corrosion were picked out.
The states of corrosion were also evaluatedby bridge engineers with a good experienceof weathering-steel bridge inspection.
From a viewpoint of maintenance practice, the most important information iswhether or not a state of corrosion requires
attention. Since the attention is needed forthe corrosion state of Level 1 or 2, the targetof the trial is to identify the corrosion stateof Level 2 or worse. The classification of thecorrosion states into the five levels is beyond
the scope of this study.
The careful examination of the two sets ofresults by the image analysis and the experts’
evaluation has led to a preliminary conclusion that a state of corrosion needs attention
if the maximum value of the minimum lengthof a rust particle larger than 9 mm.
Supplemental Document
Supplemental materials were prepared forhelping the evaluation of a corrosion state.
28 bridges located in various places and having various states of corrosion were inspected, yielding 190 sets of data. Possible corrosion states are all covered. Each sample set
includes many kinds of information: three-dimensional photo (anaglyph 3D) of the steel
surface, a Scotch-tape test result, an overview photo, rust thickness and the other related data such the distance from the coast.
Fatigue Crack
A fatigue crack in an existing bridge was reported during the WG activity and inspected.

August 2015 Steel Construction Today & Tomorrow 14

Rust around the crack was brighter (Photo 3).
Since the same observation had been made in
the US, it seems that the rust color could be aclue for finding a fatigue crack.
Load-Carrying Capacity of Corroded
Girder
Unexpected corrosion is often observed at thegirder end. The girder end is subjected to theconcentrated load, the reaction at the bearing.
Therefore, the corrosion in the girder end canthreaten the safety of a bridge. Against thisbackground, the deterioration of the load-carrying capacity due to corrosion was investi-

gated numerically. The main-girder end andthe end cross girder were studied with various patterns of corrosion in them. The computation indicates that not only the size andthe depth of the corrosion but also the corrosion location is an influential factor for deterioration. For example, corrosion in thegirder outside the bearing (Fig. 4) has a larger influence, thus requiring more attention if
found.
Repair by Painting
Difficulties have been pointed out as for the
repair of the weathering steel bridge: it is noteasy to remove the rust from weathering steel
surface and the removal of salt deposit is noteasy, either. Nevertheless, as those removals are very important, the repair work of theweathering steel bridge is said to take much
more time.
WG had a chance to repair a corroded
weathering steel bridge. With the consent
of the bridge owner, valuable in-situ dataon repair work were taken at this actual repair work as to the effectiveness of a surfacepreparation method.
Based on the data, WG recommends thefollowing method: the power tool cleaning is
conducted first; the procedure of blasting followed by water-washing is repeated twice;
and the finishing blast is carried out.
The data shows that even for the Level 1
corrosion state, a satisfactory result including
the salt deposit of no more than 50 mg/m2 isachieved by this method. It is also confirmedthat the number of blasts can be less for a corrosion state of Level 2.
Concluding Remarks
In general, most of the weathering steel
bridges in Japan are in good shape. Yet there
are some that do not meet the expectation.
Maintenance work is therefore important.
The WG activity described herein will help
solve some issues associated with the maintenance work. The activity continues to provide further technologies that would help
keep the civil infrastructure of the weathering steel bridge in good shape.
￭

Photo 3 Fatigue crack

Normalized load-carrying capacity

Fig. 4 Load-Carrying Capacity of Corroded Main Girder

Plate thickness loss (mm)(a) Location of corrosion

15 Steel Construction Today & Tomorrow August 2015(b) Deterioration of load-carrying capacity

Special Lecture“Building National Resilience” Initiativeand Future Directions
Satoshi Fujii: After receiving the master’s degree
at Kyoto University in 1993, he became assistantprofessor at Graduate School of Engineering, Kyo-

by Satoshi Fujii
Professor, Kyoto University;
Special Advisor to the Cabinet, Cabinet Secretariat
The risk of Japan suffering one or more unprecedented natural disasters is huge andgrowing quickly. To begin with, over the last
half century, the country has built a huge civilsociety in which highly complicated and diversified elements are organically linked toeach other. On top of this, the country has
built a number of megalopolises in which theessential facilities of a modern society are excessively concentrated. Further, these megalopolises are located in areas that have been
severely impacted in the past by the Kanto earthquakes, Nankai Trough earthquakes
and Mt. Fuji eruptions, and that are apparently forecasted to suffer a succession of simi-

larly large disasters in the near future. (Refer to Fig. 1)
Outline of the “Building National Resilience” Initiative
In light of this background, the Japanese government began an initiative in 2015 known
as “Building National Resilience-Creatinga Strong and Flexible Country,” with threemajor objectives:• To break the current devastating situationof forecasted attack of unprecedented mega-disasters• To minimize as much as possible the destructive effect of these mega-disasters on the fu-

Fig. 1 Megathrust Earthquakes Forecasted to Occur in Japan
Nankai Trough Earthquake(publicly announced in 2013)

Inland Earthquake in Tokyo(publicly announced in 2013)

M8~M9-class earthquake to occur with a probability of
about 70% in coming 30 years

M7-class earthquake to occur with a probability of
about 70% in coming 30 years

Predicted human casualties

Predicted human casualties• Casualties due to building collapse
Fatalities: Approximately 17,000~82,000 persons• Casualties due to tsunamis
Fatalities: Approximately 13,000~230,000 persons• Casualties due to ﬁreFatalities: Approximately 1,600~22,000 persons

Maximum damage:
Approximately 323,000 fatalities(incl. other damages)
Predicted monetary damages
Damage to assets (disaster-stricken areas, land sides)• Private sector ￥148,400 billion• Semi-public sector ￥900 billion(Electricity, gas, communications, railways)• Public sector ￥20,200 billion
Total ￥169,500 billion
Effect on economic activities (nationwide)• Loss due to degraded production
and services ￥44,700 billion• (Of the above, loss due to trafﬁc disruption
Disruption of highways and railways ￥6,100 billion)

Maximum loss:
Approximately ¥214,000 billion(incl. other losses)
Source: “Forecasted Scale of Disasters Caused by
Nankai Trough Earthquake”(Secondary Report)
prepared by Cabinet Secretariat• Casualties due to collapse of buildings
Fatalities: Approximately 4,000~11,000 persons• Casualties due to ﬁreFatalities: Approximately 500~16,000 persons

Maximum damage:
Approximately 23,000 fatalities
Predicted monetary damages
Damage to assets (disaster-stricken areas)• Private sector ￥42,400 billion• Semi-public sector ￥200 billion(Electricity, gas, communications, railway)• Public sector(Lifelines, public civil engineering facilities, etc.) ￥4,700 billion
Total ￥47,400 billion
Effect on economic activities (nationwide)• Loss due to degraded production and services ￥47,900 billion• (Of the above: Loss due to trafﬁc disruption
Suspension of functions of highways, railways, ports/harbors￥12,200 billion)

Maximum loss:
Approximately ￥95,000 billion(incl. other losses)
Source: “Forecasted Scale of Disasters Caused by Inland
Earthquake in Tokyo and Its Countermeasures”(Final Report) prepared by Cabinet Secretariat

to University. He became professor at Tokyo Institute of Technology in 2006, and assumed his current position as professor at Graduate School ofEngineering, Kyoto University in 2009.

ture of Japan• To avoid for the country to fall in a serious
situation in which the nation could never return to its original state due to these disasters
The Abe Cabinet, led by Prime Minister
Shinzo Abe, was inaugurated in December
2012. Following that, the cabinet position of
Minister in Charge of Building National Resilience was created; concurrently, the National Resilience Promotion Office was established in the Cabinet Secretariat. Centeredin this new office, the Building National Resilience initiative is being extensively promoted in all ministries and agencies.
Parallel to these endeavors, deliberations
were held in the national assembly that resulted in the enactment of the Basic Act for
National Resilience in December 2013. In
this act, it was clearly stated that the National Resilience Promotion Office, led by theprime minister, would be established in thecabinet, and at the same time it was obliged
to work out a Fundamental Plan for Building
National Resilience that would rank highest
among all administrative plans nationwide(Fig. 2).
Fifteen Serious Situations and National Resilience
In working out the Fundamental Plan for
Building National Resilience, the government identified 45 serious situations thatmight occur. In particular, 15 of these situations were assigned priority status requiring that immediate measures be implemented (see Table 1).
Each of these 15 serious situations wereselected keeping in mind the likely occurrence of mega-thrust earthquakes and various
other kinds of natural disaster. Among the
major countermeasures for these situations
are seawall improvements, seismic reinforcement, measures against land liquefaction andother hardware measures, and disaster-prevention training, close communication on

August 2015 Steel Construction Today & Tomorrow 16

risk assessment, promotion of business continuity plans and other software measures.
A key for the successful promotion of thesecountermeasures is that they be jointly andcomprehensively implemented by all governmental and private sectors from a variety ofperspectives.
Furthermore, the most important measures that should be aggressively promoted
in order to avoid these serious situations are
the “easing of the intense concentration ofdiverse functions in the nation’s capital Tokyo” and the “formation of nationally distributed functions.” That is, the easing of function concentration and distribution of thesefunctions nationwide not only can serve as anextremely effective measure for building national resilience but also will produce the following three benefits:• Drastic mitigation of the impact of disasters
caused by an inland earthquake that strikes
the Tokyo capital region• Post-disaster preservation of national vitality• More vigorous and speedier implementationof rescue, restoration and reconstruction activities
In addition, another expected merit is:• Greater contribution to building resilience inlocal areas through the re-activation of theseareas due to the diffusion and distributionof functions

In recognition of this, the Fundamental Plan for Building National Resilience
was decided in June 2014 at a cabinet meeting based on the Basic Act for National Resilience. It is clearly described in the Fundamental Plan that two major goals should bepromoted-easing of the intense concentration of functions in the capital, Tokyo, andthe nationwide formation of locally independent municipalities with dispersed essentialfunctions and regional collaboration.

In order to steadily attain these two goals,
it will be necessary to devise software measures conducive to accelerating the attainment of these two goals, such as reexamination of appropriate taxation, subsidy andsupport systems and conventional multifaceted mechanisms. At the same time, it goes
without saying that hardware measures toaccelerate the attainment of these two goals
must be assigned greater importance.
(Refer to Fig. 3)

Table 1 Fifteen Serious Situations Cited by the Government as Requiring Rapid
Measures• Collapse of high-rise and other buildings in urban areas and outbreak of large fires in such areas• Prodigious loss of life due to tsunamis• Prodigious loss of life because of inadequate transmission of information• Absolute lack of rescue and emergency activities by self-defense forces, the police, fire fighters, etc.
• Increase in fatalities due to insufficient supply of food and other necessities to disaster-stricken areas• Prolonged inability to use telephones and radios• Suspension of energy supply• Suspension of energy supply to domestic industries• Significant reduction of national economic productivity• Suspension of food supply• Disruption of transportation arteries connecting eastern and western parts of the country• Disaster-induced dysfunction of central government• Prolonged inundation of towns due to extensive flooding• Occurrence of terrible disasters due to large-scale volcanic eruptions, etc.
• Devastation of farmland and forests that account for 80% of national land area

Fig. 3 Fundamental Goals of the “Building National Resilience” Initiative and Related Promotion Efforts

Fundamental goals of Building National Resilience initiative
Fig. 2 Image of “Fundamental Plan for
Building National Resilience”
to Be Promoted as Priority Plan
Building National Resilience
Fundamental Plan

Basic Disaster
Prevention Plan

National Spatial
Strategies(National Land
Use Plan)

Sector-speciﬁc Plan

Whenever a disaster occurs:• Protection of human life by any means• Avoidance of fatal damage to important national and societal functions• Minimization of damage to national assets and public facilities• Swift restoration and reconstruction
With the establishment of these four fundamental goals,
the Building National Resilience initiative is aimed at building a safe andsecure nation with local areas and an economic society that are strong and ﬂexible.

Basic procedure for promoting the Building National Resilience initiative-Thoroughgoing implementation of PDCA (plan-do-check-act) cycleClariﬁcation of ﬁnal goals, identiﬁcation and analysis of major risks

Strategic Energy Plan
Basic Environmental Plan
Basic Plan for Food, Agriculture andRural Areas
Priority Plan for Social Infrastructure
Development
Sector-speciﬁc Plan
Sector-speciﬁc Plan

Risk scenarios and their effect: Analysis, evaluation and identiﬁcation of vulnerability

Vulnerability: Analysis and evaluation, tasks involved in vulnerability assessmentand examination of countermeasures to treat vulnerability
Review of necessary policies, prioritization of countermeasures, planned
implementation of prioritized countermeasures

Sector-speciﬁc Plan
Sector-speciﬁc Plan

17 Steel Construction Today & Tomorrow August 2015

Evaluation of results, review and improvement of the initiative as a wholeFundamental Plan for Regional Resilience
Following the central government’s establishment of the Fundamental Plan for Building National Resilience that prescribes the direction for developing national resilience, thecentral government prepared guidelines fordevising a “Fundamental Plan for Regional
Resilience” and strongly encouraged the nation’s local governments to work out theirown fundamental plans. As a result, nearly
half the nation’s local governments are preparing specific plans of their own (refer toFig. 4).
Concurrently, the central government isdeliberating on the integration of both regional resilience and regional revitalization
efforts by local governments. The main cause

Among specific measures are the enhancement of private sector resilience, apart from
central and local government initiatives;
the promotion of school training programs
aimed at educating children about the philosophy behind building national and regional
resilience-“building of disaster-prevention
nation and towns”; and the promotion of aframework for international cooperation.
The Building National Resilience initiative is being promoted as a national project
under the direction of the central government
and in cooperation with local governments,
private sector organizations, individual citizens and related nations.
￭for integration is that, when regional revitalization is attained, regional resilience after suffering a disaster will naturally be improved; and, further, initiatives to secure
regional resilience in response to disasters
will bring about diverse advantages to the
local economy during a normal period. Furthermore, it is needless to say that the reduction of the intense concentration of functions
in Tokyo, a top priority in “Building National Resilience,” will directly promote regional revitalization.
“Building National Resilience” as a
National ProjectCurrently, the Japanese government is discussing diverse measures to promote the
Building National Resilience initiative.

Fig. 4 Local Governments to Publicly Announce Start of Effort to Work Out “Building Regional Resilience” Initiatives(incl. planning stage)
As of December 12, 2014: 25 prefectures, 1 metropolis and 9 cities/towns
Notes
1) The ﬁgure shows the prefectures, metropolis and cities/towns
that have begun regional resilience initiatives(conﬁrmed by National Resilience Promotion Ofﬁce,
Cabinet Secretariat as of December 12, 2014).
2) *: 22 prefectures and cities/towns subjected to the survey in working
out the regional resilience initiative model
Hokkaido Pref.*Niigata Pref.
Mutsu City in Aomori Pref.*Niigata City in Niigata Pref.*Nagano Pref.
Matsumoto City in Nagano Pref.*Iwate Pref.

Toyama Pref.
Gifu Pref.*Shiga Pref.*Kagawa Pref.*Tottori Pref.

Tochigi Pref.

Osaka Pref.
Asahi City in Chiba Pref.*Okayama Pref.

Yamaguchi Pref.

Arakawa City in Tokyo Metropolis*
Tokyo Metropolis

Fukuoka Pref.*Kanagawa Pref.

Nagasaki Pref.*Yamanashi Pref.*Shizuoka Pref.*Oita Pref.

Tokushima Pref.*Kochi City in Kochi Pref.*Kochi Pref.*Mie Pref.
Nara Pref.*Wakayama Pref.*Aichi Pref.*Nagoya City in Aichi Pref.*Ise Town in Mie Pref.*Wakayama City in Wakayama Pref.*August 2015 Steel Construction Today & Tomorrow 18

JISF Operations

Steel Structure Conferencein Cambodia

The Japan Iron and Steel Federation (JISF) held a conference titled “Recent Technologies for Steel Structures 2014” in Phnom
Penh, Cambodia on December 4, 2014. It was held jointly with
the Ministry of Public Works and Transport of Cambodia and theInstitute of Technology of Cambodia.
Five lectures covering such topics as ports and harbors, bridges and building construction were delivered by experts from both
Japan and Cambodia at the conference, to which approximately 120 engineers and university students attended. Concurrently
with the conference, a Small Group Session of key persons fromboth nations was held for the exchange of opinions and informa-

Seminar on Seismic
Resistance in Thailand

JISF in collaboration with the Iron and Steel Institute of Thailand held a seminar titled “Seismic Design Code and Earthquake
Countermeasures Technology” on February 12 and 13, 2015 in
Bangkok, Thailand. Triggered by an earthquake that occurred in
May 2014 in Thailand and reflecting the resultant growing concern about seismic-resistant technologies for buildings in thatcountry, the seminar was planned as one of the Steel Cooperation Programs stipulated in the Japan-Thailand Economic Partnership Agreement.
Three experts from Thailand and two from Japan delivered
lectures on seismic design and seismic-resistant technologies atthe seminar, to which 80-plus people attended. JISF and the Iron
and Steel Institute of Thailand plan to jointly hold a “Seminar on
Technology Transfer for Steel Construction Promotion” in Bangkok in September 2015.

Lecture delivLecture deery by General livery by Staff
Manager Dr. Ya- Manager Yukio
sushi Ichikawa Murakami, JFE
of Nippon Steel Steel Corp.
& Sumikin Engineering Co., Ltd.

Greeting by
Acting President Pairojana
Meethawee,
Iron and SteelInstitute of Thailand

Lecture delivery
by Advisor Nuttapon Suttitam,
Iron and SteelInstitute of Thailand

STEEL CONSTRUCTION TODAY & TOMORROW
Published jointly by

The Japan Iron and Steel Federation
3-2-10, Nihonbashi Kayabacho, Chuo-ku, Tokyo 103-0025, Japan
Phone: 81-3-3669-4815 Fax: 81-3-3667-0245
URL http://www.jisf.or.jp/en/index.html
Japanese Society of Steel Construction
Yotsuya Mitsubishi Bldg. 9th Fl., 3-2-1 Yotsuya, Shinjuku-ku, Tokyo 160-0004, Japan
Phone: 81-3-5919-1535 Fax: 81-3-5919-1536
URL http://www.jssc.or.jp/english/index.html

tion regarding current conditions and future tasks pertaining to
the wider application of steel structures in Cambodia.
This conference is the second in the series and follows a conference held by JISF in 2012. JISF plans to hold a third conference in December 2015 in Cambodia.

Conference on “Recent Technologies for Steel Structures 2014” heldin Phnom Penh

Opening of South East
Asia Regional Office

JISF opened its South East Asia Regional Office in Kuala Lumpur, Malaysia and held an opening ceremony on April 28, 2015 tomark the start of regular operations. The Regional Office serves
as a liaison that promotes collaborative operations between theJapanese steel industry and the ASEAN steel industry. Also, itcollects information in a wide range of fields by developing human networks with the iron and steel organizations of the ASEAN
region and, at the same time, conducts diverse activities to promote better understanding of the Japanese steel industry.
The office information is as follows:
South East Asia Regional Office
The Japan Iron and Steel Federation
Suite 8-1 & 8-2, Level 8, Menara CIMB, No.1, Jalan Stesen Sentral 2,
50470 Kuala Lumpur, Malaysia
Phone: +60-3-2298-8307 Fax: +60-3-2298-8201

Opening ceremony and greeting by
Executive Director Yuzo Ichikawa of
JISF at the opening ceremony© 2015 The Japan Iron and Steel Federation
Edited byCommittee on Overseas Market Promotion, The Japan Iron and Steel Federation
Chairman (Editor): Kaoru Uehara
P u b l i s h e d t h r e e t i m e s p e r y e a r, S T E E L C O N S T R U C T I O N TO D AY &TOMORROW is circulated to interested persons, companies and publicorganizations to promote a better understanding of steel products and theirapplication in the construction industry. Any part of this publication may be
reproduced with our permission. To download content (PDF format), please go
our website at: http://www.jisf.or.jp/en/activitity/sctt/index.html. We welcome yourcomments about the publication and ask that you contact us at: sunpou@jisf.or.jp.