No. 53 April 2018

STEEL CONSTRUCTIONTODAY & TOMORROW

http://www.jisf.or.jp/en/activity/sctt/index.html

Special Issue

Japanese Society of
Steel Construction
JSSC Commendations for Outstanding Achievements in 2017

• JSSC Awards

1 Osman Gazi

Bridge in Turkey• Outstanding
Achievement
Awards

3 Shinjuku Toho
Building

4 [ Tokyo Garden

Terrace Kioicho]
Kioi Tower• Thesis Awards

TM&ⒸTOHO CO., LTD.

5 Relationship of Macro Stress and Maximum Principal Stress on
Electro-slag Weld Zone
6 Fatigue Crack Growth Rate of Steel under Large Cyclic Strain and
Its Application

Feature Articles: Japanese Steel Construction Technologies

7 Passenger Terminal of New Doha International Airport
10 Taipei Nanshan Plaza Project in Taiwan
13 Tsubasa Bridge in Cambodia
Special Article: Stainless Steel

16 Lean Duplex Stainless Steel for Selective Water Intake Facility
18 JSSC International Events
Back cover Message from JSSC International Committee Chairman
Published Jointly by

The Japan Iron and Steel Federation
Japanese Society of Steel ConstructionJSSC Commendations for Outstanding Achievement in 2017—JSSC Awards

Osman Gazi Bridge in Turkey

Prize-winner: IHI Infrastructure Systems Co., Ltd.
Project Overview
The Osman Gazi Bridge named in honor of Osman I (1259-1326, who founded
the Ottoman Empire in 1299), locates innorthwest Turkey and carries the Gebze-Orhangazi-Bursa-Izmir motorway
across the Sea of Marmara at the Bay of
Izmit between the Diliskelesi Peninsulaon the north and the Hersek Peninsula on
the south.
The bridge, contracted to IHI Infrastructure Systems Co., Ltd. (IIS) on an
EPC (Engineering, Procurement andConstruction) basis, was constructedwith a 1,550 m main span making it the
fourth longest suspension bridge in theworld. The scale of the bridge and thetight construction schedule in the EPC
contract required the state-of-the-art andsustainable design, well-proven construction methods adapted to the technical challenges and financial success forthe project. (Refer to Fig. 1)
Construction was started in January
2013 and the bridge opened to traffic
on July 1st, 2016 only within 3.5 years.
More than 83,000 tons of steel has beenused and 200,000 m3 of concrete has
been cast in total. (See Photos 1 and 2)
Engineering Challenges
Since the bridge locates in a high seismic zone where magnitude 7.4 Kocaeli
Earthquake took place in 1999 along theNorth Anatolian Fault (NAF), high durability against huge seismic events is required with achieving very fast and safe
construction. To realize this requirement,
IHI has managed and collaborated witha number of subcontractors in more than
10 countries and overcome many engineering challenges.
The tower foundations are concrete
caissons placed 40 m below sea level ona gravel bed over soil strengthened by
195 nos. of the steel inclusion piles per
tower (Fig. 2). The tower foundation isallowed to move by releasing friction,functioning as an isolation system during
a huge earthquake (return period of 2,500
years). The NAF is running close to thebridge site, around 2 km away from thesouth anchorage area, and the south anchorage is in the secondary fault zone. It
is the first case in the world in which thisisolation system is applied to the suspension bridges.
1 Steel Construction Today & Tomorrow April 2018

Fig. 1 General Arrangement of Osman Gazi Bridge
120 000
92 050+EL.63.050(stiffening girder)+EL.57.500 (cable)

2 682 000

North side
span pierNorth anchorage

105 000

1 550 000
Main span

566 000
North side span
North tower+EL.252.000

North tower
foundation

566 000
South side span

Main span+EL.24.000

Istanbul[Unit: mm]+EL.80.330 (cable)+EL.77.080(stiffening girder)

Navigation clearance (height) 64 300
Navigation clearance (width) 1 000 000

South tower+EL.252.000

67 250South side
span pier+EL.63.050(stiffening girder)+EL.57.500 (cable)+EL.33.023

South tower
foundation+MSL.+0.401

South anchorage
Bursa
Legends
EL. : Elevation (unit: m)
MSL. : Mean sea level (unit: m)
EJ. : Expansion joint

Photo 1 Aerial view of Osman Gazi Bridge

Photo 2 South anchorage area and the bridge

The two towers are 252 m high, eachconsisting of two single-celled box legswith two cross beams. The steel towers
have been chosen to minimize the wholeconstruction period by overlapping thefoundation work at the seabed, the cais-son fabrication work and the tower fabrication work, although the concrete towers are common for the long-span bridges
in the world except for in Japan where
technology of the steel towers has beendeveloped. Each tower leg is divided in-Fig. 2 Schematic Image of Tower Foundation

Photo 4 Main cable erection by PPWS method

Photo 5 Deck erection by lifting device

Photo 3 Tower block erection by floating craneto 22 blocks, erected by floating crane
for the lower half and by jib-climbing
crane for the upper half and connectedeach other by combined method of welding and HSFG bolt connection (Photo 3).
The main cables are made of a prefabricated parallel wire strand (PPWS),
each consisting of 127 high strength steel
wires of 5.91 mm in diameter and having
a breaking strength of 1,760 MPa. 110
PPWS per one main cable are spanned
between the cable anchorages and 2 extra PPWS are placed between the tower
and the cable anchorage on both sides. It
is the biggest diameter of the wires usedin the PPWS method in the past suspension bridges and it makes the anchorages at both ends smaller for less concrete
volume and shorter construction period.
(See Photo 4)
The deck is a hexagonal closed steel
box girder with a width of 30.1 m anda depth of 4.75 m and is carrying threelanes of highway traffic in each direction. The walkway for maintenance vehicles with a width of 2.9 m is at both sidesof the steel deck similar to the 1st andthe 2nd Bosporus Bridges. The deck is
divided into 117 segments of 25 m length
typically due to the capacity of lifting de-vices for erection (Photo 5). To achieve
further shortening of the construction
period, the typical 2 blocks in the main
span were connected into a 50 m longblock by welding at the fabrication shop.
This reduces the number of on-site welding joints (thus welding work) and theperiod between the deck closure to thetraffic opening into only 2 months.
Contribution to Social Development
In the project, more than 100 Japaneseengineers were stationed in Turkey atthe fabrication shops or on site to supervise the fabrication work and superstructure construction works. The purpose ofthis supervision is not only to construct
the bridge with high quality based onJapan’s experiences but also to transfer
their knowledge to Turkey and to contribute to Turkey’s technology development.
Furthermore, the project welcomed
many internship students from Turkey
and abroad and site visits by local children who will play important roles in the
future. (Photo 6)
Acknowledgement
The authors are deeply grateful to KGM(General Directorate of Highway, MOT
Turkey) and OTOYOL YATIRIM VE ISLETME A.S for guiding us to a successful completion and their permission on
publication of this paper. ￭Photo 6 View at tower top
April 2018 Steel Construction Today & Tomorrow 2

—Outstanding Achievement Awards

Shinjuku Toho Building

Prize-winner: Takenaka Corporation
The Shinjuku Toho Building is a complex building that accommodates a movie theater, shops and a hotel. Featuring
a slender façade, it has 30 stories above
ground and a height of 130.25 m. The
building was completed in 2015 in Shijuku-ku, Tokyo. (Photo 1)
Response Control Using Extra
High-strength CFT and New
Diaphragm Plate Specifications
The ratio of height to width of the highrise section of the building is quite large,
6.8 at maximum, and further the horizontal stiffness of the low-rise section differs
greatly from that of the high-rise section.
Because of this, the horizontal deformation of the high-rise section becomeslarge during earthquakes (Fig. 1).
To solve this problem, it was necessary to control the horizontal stiffness of
the low-rise section so that it does notmuch exceed that of the high-rise section, although the columns of the lowrise section were required to have sufficient strength. In order to satisfy thesetwo conflicting requirements, extra highstrength concrete-filled steel tube (CFT)
columns were adopted that employ 780
N/mm2-grade high-strength steel and Fc
100 N/mm2-grade concrete. This facilitated the successful control of horizontal
stiffness between the low-rise and highrise sections during earthquakes (Fig. 1).
As the inner diaphragm plate had never been used for electro-slag welding ofcolumns employing 780 N/mm2-grade
high-strength steel, there was some concern regarding the securement of welding quality. Then, full-scale welding
tests were carried out on the electro-slag
welds to establish a steel column manufacturing method that would secure therequired Charpy value, 27J or higher(Photo 2). Consequently, specifications
for electro-slag welding of the inner diaphragm plate were, for the first time ever, put into practice for 780 N/mm2-grade
high-strength steel columns.

Development of an Improved Nonscallop On-site Welding Method
In the construction of high-rise steelframe buildings, it is essential to secure
the soundness of column-beam joints.
Concerning the design of the Shinjuku Toho Building, we developed an“improved non-scallop on-site welding method” as the new beam end detail(Fig. 2). With this method, the plastic deformation capacity of the column-beamjoints can be improved by filling up onsite weld scallops by means of welding
and without the expansion of beam ends.
After tests using full-scale T-shaped
specimens were conducted on the newly-developed welding method in order toconfirm the high deformation capacity of
the column-beam joints, the method was
put into application. The newly-developed method offers high applicability forcommon uses and is expected to be usedin many new building construction projects in the future. ￭Fig. 1 Response Control by the Use of CFT Columns
Employing 780 N/mm2-grade High-strength Steel
Image of deformation
after control of stiffness

Securement of
sufﬁcient strength
obtained by the useof extra high-strength
CFT column

Image of deformation
before control of stiffness

Photo 2 Macroscopic test resultsfor electro-slag weld

Fig. 2 Details of Improved Non-scallop
On-site Welding Method
Column skin plate
Diaphragm plate

Photo 1 Symbolic façade ofsouth-side surface

TM&ⒸTOHO CO., LTD.

3 Steel Construction Today & Tomorrow April 2018

On-site welding

Beam ﬂange

[Tokyo Garden Terrace Kioicho]
Kioi Tower

Prize-winners: Yuichi Koitabashi, Seiya Kimura, Nikken Sekkei Ltd.; and Kajima Corporation
In the plans for the [Tokyo Garden Terrace
Kioicho] Kioi Tower, the following original ideas (A and B), devices and advanced
measures were incorporated to handle thevarious tasks involved in the design andconstruction. These ideas led to an architecture that contributes to the development
and diffusion of steel structures.(Photo 1)

A: Ensure high seismic performancein which the main structure will remain elastic and the floor response acceleration will be 250 gal or less during a major earthquake, including aninland earthquake in the Tokyo area, toenable the functions of the offices andhotel to be maintained continuously.

In this way, a high durability long life
ultra high-rise building was realized ineconomizing on steel resources and minimizing damage to building materials
from a long-term perspective. Therefore
a new “high efficiency hybrid vibration
control system” that combines the following 1) and 2), and other innovative
measures were incorporated.
1) An innovative vibration control system
was devised utilizing the properties ofthe building scheme that was capableof attaining high energy absorption efficiency and capable of reducing the seismic force (story shear force) on eachstory, using the deformation propertiesof a large structure consisting of thetransfer truss structure and coupled steel
plate walls. The energy absorption efficiency was increased by a maximum

Fig. 1 Overview of Vibration Control
SystemFig. 2 Vibration Control Device Layout
DiagramUltra High-rise Building with High
Seismic Performance

Large axial deformation

Hysteretic buckling
restrained vibration
control brace

Velocity dependent
viscous vibration
control brace

Effective
deformationof the brace
vibration control
devices ampliﬁed

Beforedeformationof about 50% compared with a normal
ultra high-rise building, and the story
shear forces were reduced to about 75%(Figs. 1~3).
2) Comprehensive monitoring was carriedout such as measurement of floor response accelerations, displacements withthe aim of achieving a long life steel
structure building, to enable effective
maintenance of the vibration control devices, which are indicative of the degreeof damage in an earthquake.
High Efficiency Hybrid Vibration
Control System
B: Scheme to reduce vibrations after
a long period earthquake or a major
earthquake
For this purpose an active mass damper (AMD) was installed on the roof. The
AMD has an additional mechanism capable of reducing the amplitude of thevibrations after an earthquake by about
30 to 50% and shortening the time period of oscillation by about 3 minutes
compared with no vibration control,with the aim of enabling rapid evacuation activities.

After
deformation
Large axial deformation

Fig. 3 Time History of Axial Forces Generated in the Vibration
Control System (1 Unit)
Axial force (kN)
3000

Absolute sum of maximum force
generated individually in hysteretic
velocity dependent dampers

Maximum positive and negativevalues of axial force generated in
the time history with this system

2000
1000
0
−1000
−2000
−3000

Reduction to about 75% of the absolute sum of each of the
maximum generated forces, by the phase difference between
the hysteretic dampers and the velocity dependent dampers

Time (sec)

Photo 1 Full view of [Tokyo Garden Terrace Kioicho] Kioi Tower

April 2018 Steel Construction Today & Tomorrow 4

—Thesis Awards

Relationship of Macro Stress andMaximum Principal Stress on Electroslag Weld Zone between Interior
Diaphragm and Box Column

Prize-winner: Takumi Ishii, JFE Techno-Research Corporation

ing. In the electro-slag weld (hereinafter referred to as ESW) of the interior diaphragm and column skin plateof a column, it is worried that cracking will break out from the slit tip occurring between the backing metal andthe column skin plate after welding(Fig. 1).
While there are no reports of actual damage caused by such cracking, it isclear from recent experiments that thereis the possibility of brittle fractures occurring in the interior diaphragm ESW
under specified conditions. Triggered bysuch experimental results, higher toughness is required of ESW.

Takumi Ishii

1991: Graduated from Graduate School of Engineering, Chiba University;
Entered Kawasaki SteelCorporation

2003: Civil Engineering Dept., JFE R&D Corporation
2009: Steel Research Laboratory, JFE SteelCorporation
2017: Structures Performance Center, JFE
Techno-Research Corporation

Higher Toughness for ESW
The built-up box section column ismanufactured by weld assembling four
steel plates using electro-slag weld-

Fig. 1 Outline of Column-Beam Connection of Box Column andAnxiety over Brittle Fracture Occurrence
Built-up box section column

Interior
diaphragm

Backing
metal

Position of anxiety overbrittle fracture occurrence

H-section beam
ESW

Equivalent value of maximum
principal stress at fracture
initiation point (N/mm2)

Fig. 2 Relationship between Equivalent
Value of Maximum Principal
Stress at Fracture Initiation
Point and ESW Toughness Level

Partial model experimentPartial framing modelexperimentToughness level of ESW (J)Macrostructure of column-beam
weld joint section

Fig. 3 Relationship between
Dimensionless Maximum
Principal Stress andDimensionless DiaphragmStress that Takes Penetration
into Account (Conversion Curve)
Dimensionless maximum
principal stress σm,HAZ /cσu

SAW

ColumnDimensionless diaphragm stress dσaf /cσu

5 Steel Construction Today & Tomorrow April 2018

Studies on ESW Fracture Toughness
Two studies on ESW fracture toughness were reported by us in past issuesof Steel Construction Engineering of theJapanese Society of Steel Construction:“Study on Fracture Behaviors of Electro-slag Welds of Column-Beam Partial
Models” (Vol. 16 (2009), No. 64) and“Study on Fracture Behaviors of Electro-slag Welds of Column-Beam Partial
Framing Models” (Vol. 17 (2010), No.
68). In these studies, we noted the fracture toughness of the weld metal, fusionzone and heat-affected zone of ESW.
These two studies suggest that there
is a positive mutual relationship between
the toughness (that denotes the Charpy
impact energy here) of the weld metal,
fusion zone and heat-affected zone andthe interior diaphragm stress. In addition, analytical examinations were madeof the results of the experiments mentioned above, which find that the maximum principal stress is effective as thefracture toughness parameter that relates
to the Charpy impact energy (Fig. 2).
Estimation of Toughness Required for ESW
Given this situation, the current study
proposes a method that connects the critical maximum principal stress with theinterior diaphragm stress, which is considered important in the process of calculating the toughness value required for
ESW (Fig. 3). Concurrently, a method is
proposed that simply calculates the stressworking on the interior diaphragm of thecolumn-beam connection.
By making the most of these proposals, the maximum principal stress isfound from the stress working on the interior diaphragm of ESW without the useof the finite element analysis, and as aresult it is now possible to estimate therequired toughness in terms of the stresslevel of ESW. ￭Fatigue Crack Growth Rate of Steelunder Large Cyclic Strain and Its
Application to Crack Growth Prediction
in Welded Joints

Prize-winners: Takeshi Hanji, Associate Professor, Nagoya University; Nao Terao, Graduate
student, Nagoya University; Kazuo Tateishi, Professor, Nagoya University; and Masaru Shimizu,
Assistant Professor, Nagoya University

Low cycle fatigue is one of the failuremodes in steel structures during earthquakes. With a focus on crack growth in
the low cycle fatigue region, this study
developed a fatigue crack growth curve,
and verified its applicability to crack
growth prediction in welded joints.
Fatigue Crack Growth Tests
Fatigue crack growth tests under highly plastic conditions were performed using compact tension specimens with side
grooves. Three kinds of materials (structural steels of 400 N/mm2 and 490 N/mm2
classes, and deposit metal) were used.
Each specimen was loaded under displacement control. The range of fluctuation of
the displacement was controlled during
the test. The crack length was measured atregular intervals using a microscope. Fig.
1 (a) shows an example of a crack tip observed from the side surface of the specimen. A photograph of one of the fracturesurfaces after the test is shown in Fig. 1(b). These figures reveal that the crack
Fig. 1 Test Results
Fatigue crack

Fatigue Crack Growth Rate Formula
Elasto-plastic finite element analysis
was used to calculate the cyclic J-integral range at the cracks in the specimens.
The cyclic J-integral range ΔJ was defined as the range of fluctuation of the Jintegral from the minimum to the maximum load points of the loading process.
The cyclic J-integral range is calculated
as in the following:where W’ is the range of strain energy
density, ΔT is the range of traction vector, Δu, Δσ and Δε are the ranges of displacement vector, stress and strain in theloading process, respectively.
Fig. 2 shows the relationship between
the crack growth rate da/dN measured
during the test and the cyclic J-integral
range ΔJ calculated analytically. All plots
were distributed in the same area, meaning that the cyclic J-integral range correlates with the crack growth rate regardless

Crack propagation direction
Side
grooves

1mm

Crack tip(a) Crack tip observed
from side surface

Fracture surface due to 5mm
low cycle fatigue loading(b) Fracture surface

Fig. 2 Crack Growth Rate
vs Cyclic J-integral
Rangeof the material. Based on the results, thecrack growth rate formula can be derived.
Fatigue Crack Growth Prediction
in Welded Joints
Low cycle fatigue tests were conducted using corner welded joints. The crack
growth from the weld root in the joint
was predicted to confirm the applicability of the proposed crack growth curve.
The crack growth in the test was estimated based on the cyclic J-integral
range from the analysis and the proposed
formula by the following steps:(a) The initial crack length was definedand its cyclic J-integral was calculated based on the analysis.
(b) According to the proposed formula,crack growth length da due to one
loading cycle (dN = 1) was calculated.
(c) The crack length a was updated to
a+da, and again, its cyclic J-integral
was calculated.
(d) The crack growth length da was recalculated using the formula.
The above steps were repeated.
Fig. 3 shows the prediction results. The
predicted and observed crack growths
were in good agreement. This demonstrates that the crack growth of the corner welded joints can be predicted using
the cyclic J-integral range and the proposed crack growth formula in the low
cycle fatigue region. ￭Fig. 3 Crack Growth Prediction
in Welded Joints

SM400A
SM490A
Weld metal

da =9.6×10–6(ΔJ )1.67
dN

Cyclic J–integral ΔJ (N/mm)

Crack length (mm)2001: Graduated from Schoolof Engineering, Nagoya
University
2006-2009: Researcher, Universityof California, San
Diego; EcoTopia Science Institute,
Nagoya University; Center for Urban
Earthquake Engineering, Tokyo Instituteof Technology
2010-: Associate Professor, Graduate School ofEngineering, Nagoya University

propagated straight along the side groove,and that the location of the crack front wasalmost same throughout the thickness direction because of the side groove.

Crack growth rate da/dN (mm/cycle)

Takeshi Hanji

Test result
Prediction

Prediction

Test result

Number of cycles
April 2018 Steel Construction Today & Tomorrow 6

In the following, examples are introduced in which Japanese steel conFeature Articles:
struction technologies are applied in various countries, or examples ofJapanese Steelsteel construction projects are introduced in which Japanese companies
Construction Technologies have contributed toward the successful completion of these projects.

Feature Articles: Japanese Steel Construction Technologies (1)Passenger Terminal of New Doha
International Airport
by Tsutomu Hirata, Taisei Corporation
Outline of New Doha International Airport
In Qatar, plans called for the constructionof a new airport at a 29 km2-spacious site
(60% accounted for by reclaimed land) located south-east of Doha, the capital of Qatar. It is a leading airport in the Middle East
that consists of a passenger terminal withan initial annual handling capacity of 24
million passengers, a cargo terminal withan annual handling capacity of 1.4 million tons of cargo, two runways each witha length exceeding 4,000 m, hangars, catering facilities, a control tower and a VIP
terminal for the exclusive use of the royal family. The New Doha International Airport is a grand-scale national project composed of more than 100 contract packages.
The New Doha International Airport
Terminal, among others, is the nucleus of
the project (Photo 1). Its construction period ran about 64 months from March 2006
to July 2011. The airport was opened tothe public in 2014, establishing it as a hub
airport in the Middle East. The passenger terminal building was constructed bya joint consortium led by Taisei Corporation, a major general contractor in Japan,
and a partner company from Turkey.
Outline of Construction of New
Passenger Terminal• Tendering Details of the Project
Taisei Corporation participated in thetender for the new airport terminal building construction by forming a joint venture (Sky Oryx Joint Venture) with TAVof Turkey, who are both experienced
in airport construction and management. Pre-qualification started in April
2005, and in March 2006 the joint venture received a purchase order/construction start order, which led to the conclusion of a formal agreement between the
New Doha International Airport Steering
7 Steel Construction Today & Tomorrow April 2018

Outline of Passenger Terminal Building
Location: Doha, Qatar
Total floor area: About 484,000 m2
No. of stories: 5 stories aboveground
Type of structure: Steel structure (including concrete-filled box section columns)
Application: Airport facilities—passenger terminal and concourse
Project owner: New Doha International Airport Steering Committee
Construction management (CM): Overseas Bechtel Inc. (O.B.I.)
Design consulting: Hellmuth, Obata+Kassabaum (H.O.K.), Middlebrook+Louie(M+L, currently Louie International)
Construction: Sky Oryx Joint Venture (Taisei Corp. of Japan 65%, TAV of
Turkey 35%)
Committee and the Sky Oryx Joint Venture in June 2006.
• Outline of Terminal Building
The first-phase of the work covered theconstruction of the main terminal building composed of a main airport passenger terminal, a passenger concourse, elevated viaducts, pedestrian bridges andpassenger boarding bridges. The main
terminal building is a complex five-story
steel structure with a wave-formed archshaped roof that is supported by part concrete-filled steel box section arch columns. The second-phase of the work
consisted of an extended airport passenger concourse and girder framing for anindoor monorail that serves as a means

Photo 1 Full view of Passenger Terminal of New Doha International Airport in Qatar

of transportation from the main terminalbuilding to the more distant departure
gates. These facilities comprise a twostory steel-structure with a high vaulted
roof.
The total floor area for the first to second-phase works is about 490,000 m2
and the amount of steel used came toabout 54,000 tons. While the construction work for the main terminal building had to overcome strict restrictions
imposed by the harsh desert climate, logistic constraints and local practices, themain terminal building saw a full-scale
opening on May 27, 2014.
• Steel Frame Construction
The main passenger terminal and its connecting concourse section have an approximately 1 km×1km square footprint with a
total floor area of about 490,000 m2. The

arch columns, hybrid steel-composite
structures, were adopted in constructing
the passenger terminal and concourse section, where a large-span arch-shaped terminal building roof structure was built using part concrete-filled steel box sectionarch columns having span lengths of 160
m and 80 m. (Refer to Photo 2 and Fig. 1).
The upper arch-shaped hollow steel
framing of the main building was installed on top of the lower concrete-filled
box section arch columns. The length ofsteel-frame members for the main building measures from 40 m to 60 m in maximum. Three airport passenger concourses extend to the east, west and north sidesof the terminal building.
All the arch-shaped steel framing wasassembled on the ground, and the temporary support bent construction method
was adopted for the erection of the steel

framing.
During the construction of the hugeterminal building, notable changes weremade to the terminal design prior to andafter the start of the project. To cope withthis situation, it was required that the joint
venture presented alternative proposals
and construction plans applicable to theproject. As a prime example, a proposal was submitted by the contractor prior
to the start of the project that the original
RC structure for the arch column lower
sections be changed to a concrete-filledsteel box column structure. In addition, it
was required after the start of the projectthat an additional concourse be constructed. As it was necessary for the building
contractor to be able to meet these designchanges, the Sky Oryx Joint Venture successfully cleared all these requirements tocomplete the terminal building.

Photo 2 Installation of arch column steel framing

Fig. 1 Installation Plan for Arch Column Steel Framing
Step 2: Installation, bolting andwelding of arch steel framing
Step 4: Installation, bolting and weldingof steel framing for main building

Procedure for installing steel framing
Step 1: Installation and welding of arch column steel framing
Step 2: Installation, bolting and welding of arch steel framing
Step 3: Column base mortar placement
Step 4: Installation, bolting and welding of steel framing for main building
Step 5: Concrete ﬁlling of square steel box section columns
Step 6: Jacking down and dismantling of bent
Indicating welded sections

Step 6: Jacking down anddismantling of bent

Step 5: Concrete ﬁlling of square
steel box section columns

Step 1: Installation and welding ofarch column steel framing

Step 3: Column base mortar placement

April 2018 Steel Construction Today & Tomorrow 8

Collaborative System between
Engineers from Many Countries
In this airport terminal project, as an outstandingly large-scale construction project to be undertaken in the Middle Easterncountry of Qatar, it was considered necessary to establish a multinational collaborative system for those working on the
project in order to build it efficiently.
About ten engineers and architects incharge of the contractor’s design management were stationed on site to proceedwith the project. They came from Turkey,
the Philippines, Egypt and Japan. The persons working in the construction management (Overseas Bechtel, Inc.) and design (Hellmuth, Obata＋Kassabaum andMiddlebrook+Louie) teams were mostly Americans, and the company working on the steel-frame manufacture (EVS
Metal Inc.) was an Indian company. The
sense of values of these engineers and architects and the languages they each usedwere different. One of the important roles
played by the Sky Oryx Joint Venture wasto guide the multinational engineers andarchitects towards one purpose, the successful completion of the project. (Refer
to Photo 3)

Accurate Response to Technological Issues
Diverse kinds of technological issues occurred during the terminal construction.
The steel products used for construction were imported from various nations,and thus there were many cases in which
quality, the dimensions and other specifications could not be easily and correctly judged simply by examining different mill sheets. Further, an importantrole was imposed on the construction engineer who managed the entire construction project—to judge whether or not the
specifications of the structural materials,prescribed in the structural drawings prepared by the structural design office, wereappropriate. On top of these, because diverse collaborative design offices wereused in the operations depending on theengineering capabilities and the specialized field, it was necessary to prudently
undertake the choice of collaborative engineering offices at the site.
In spite of technological issues such asthese, the terminal building was completed without major issues, supported by thetechnological strengths accumulated by
the Sky Oryx Joint Venture. In this regard,in order to successfully promote construction projects overseas, it is considered important to implement design verificationfrom multilateral viewpoints and to basethem on the on-site conditions.

Photo 3 On-site confirmation of arch column
steel framing by engineers

Photo 4 Top light of main terminal building
9 Steel Construction Today & Tomorrow April 2018

Overcoming Difficult Work in theDesert by the Optimum Use ofTechnological Strengths
The project of constructing a passenger
terminal having an originally planned total floor area of 239,000 m2 started withan initially planned construction periodof three years. Finally, a terminal having
a total floor area of 484,000 m2 was completed in a construction period of morethan five years (Photos 4 and 5).
Nearly 20,000 workers from 25 countries participated in the construction of
the terminal building. The Sky Oryx
Joint Venture dealt with complex processcontrol by promoting communications
among workers from different countries
by respecting their various cultures, religions and habits. As regards the influx ofconstruction materials supplied by various countries, the joint venture closely
monitored the unsettled delivery terms.
In addition, the contractor was facedwith difficulties in accurately following the construction schedule of such alarge-scale project and efficiently attaining the daily targets.
Even in the face of such hard conditions, the Sky Oryx Joint Venture joined
forces to proceed with the new airport terminal project—transferring to the workers the basic knowledge accumulated byexperienced Japanese engineers, training
the workers in such basic knowledge, accurately coordinating the entire project,and implementing the basic practices involved in construction management. It isbelieved that these daily accumulated efforts produced the positive results that led
to the successful completion of the terminal building of the New Doha International Airport in compliance with the high expectations of the people of Qatar, and thesupervising design and CM teams. ￭Photo 5 The huge-scale terminal project was
successfully completed by the joint efforts of workers and engineers frommany countries.

Feature Articles: Japanese Steel Construction Technologies (2)Taipei Nanshan Plaza Project in Taiwan
by Hiroshi Kawamura, Mitsubishi Jisho Sekkei Inc.

Outline of the Project
The Taipei Nanshan Plaza is a large-scale
project composed of complex facilities
that are located in the central area of Taipei, Taiwan. The project is located at avacant lot formerly used as an exhibitionsite and adjoins the Taipei 101, a 101-story high-rise building with a height of 509
m, the tallest in Taiwan. After completion of the current project, the pair consisting of Taipei Nanshan Plaza and Taipei 101 will constitute a new landmark in
Taipei (Fig. 1).
Mitsubishi Jisho Sekkei Inc. jointly with its client, Nan Shan Life Insurance Company Ltd., participated in the
project competition held by the Taiwan
City Government in 2012, in which our
proposal was adopted after winning firstplace in the competition. Nan Shan Life
Insurance Company, a major Taiwaneselife insurance company, is the owner anddeveloper of the project. The company
leases the land from the Taiwan Government and also develops and operates the
Taipei Nanshan Plaza.
The Taipei Nanshan Plaza project iscomposed of three buildings: an office
tower with a height of 272 m with restaurants in the three topmost floors, a retailbuilding housing top-brand shops, and acultural building where various eventsand exhibitions are to be held. Bus terminals are located in the undergroundfloor of the cultural building. These threebuildings with a total floor area of about
200,000 m2 are designed and constructed
as one unified building complex.
Construction started at the end of
2013. Currently, the project is underwaywith completion scheduled for the end of
March 2018. The Taipei Nanshan Plazais becoming the focus of public attention
in Taipei. Table 1 shows an outline of thethree buildings.

As a result of these processes, Mitsubishi Jisho Sekkei was able to successfully establish a highly reliable relationship with the client and the local
engineers, which led to a structural design that imparts a unique configuration
and a striking design concept to eachbuilding.
Fig. 1 Image of a Pair of Landmark
Towers in Taipei: Taipei Nanshan Plaza (left) and Taipei 101

Design Approach
While Nan Shan Life Insurance was proJapanese and possessed a positive outlook in incorporating advanced technologies from Japan into the design of the
project, Mitsubishi Jisho Sekkei did notparticularly impose Japanese styles on its
client, but rather respected local customs,
laws, regulations and procurement procedures. In light of this, Mitsubishi Jisho
Sekkei conducted advance exchanges of
opinion with local engineers and authorities when examining the various proposals for the Taipei Nanshan Plaza project,
and when explaining these proposals to
the client, we stressed that the proposals
were prepared after consulting with local
engineers and authorities.

Table 1 Outline of Three Buildings in Taipei Nanshan Plaza
Office tower

Retail building

Location

Sung Jen Road, Xinyi District, Taipei, Republic of China (Taiwan)

Main applications

Office and carpark

Site area

17,708.00 m2

Building area

10,271.41 m2

Total floor area

192,891.35 m2

No. of stories

5 stories underground, 48
stories aboveground, 2-story
penthouse

Cultural building

Shop and carpark

Cultural facility and entrance
to office tower

5 stories underground,
9 stories aboveground5 stories underground,3 stories aboveground

Maximum height272.00 m

56.75 m24.61 mType of structure

Aboveground: Steel structure(~36 floors: CFT column)
Underground: SRC structure

Aboveground: Steel structure(CFT column)
Underground: SRC structure

Aboveground: Steel structure(partially CFT column)
Underground: SRC structure

Grade of steelwork

SN490B, SN490C, SM570C; Maximum plate thickness: 70 mm; Maximum column size: 2000 mm×1400 mm

Project owner

Nan Shan Life Insurance Company Ltd.

Scheme design/Supervisionof design development anddetail design

Mitsubishi Jisho Sekkei Inc.

Design development anddetail design

Architect: Archasia Design Group; Structural engineer: Evergreen Consulting Engineering, Inc.

Contractor

Fu Tsu Construction Co., Ltd.; Steelwork fabricator: Chun Yuan Steel Industry Co., Ltd.

April 2018 Steel Construction Today & Tomorrow 10

Structural Design Concept• Office Tower
The office tower has 48 stories aboveground and a height of 272 m, and the ratio of height to breadth is about 5.8 (Photo 1). The frame is a double-tube structurecomposed of a core in which braces (548 floors) and steel plate seismic-resistant walls (1-4 floors) are arranged in the
short-side direction and an outer peripheral frame. With regard to the overall appearance of the office tower building,the building’s frame is designed to promote the idea of two joined palms (Fig.
2), and with regard to the outer appearance of the low-rise section, the frame isdesigned to offer a unique configurationin which the outer wall surface becomesnarrower toward the bottom (Fig. 3).
Meanwhile, in order to secure bothhorizontal and torsional rigidity for thebuilding structure, truss floors were provided on the top and intermediate parts
and the lower part where the perimetercolumns are bent (Fig. 3). Intermediatemachine rooms are located on these truss
floors with belt trusses used for the outer periphery and outrigger trusses for theinterior sections.
In the office tower building, the windload is more predominant than the seismic load, and in order to suppress thevibration caused by the wind load, twotuned mass dampers (TMDs) weighing
250 tons each were installed on the upper truss floor.
At the topmost section of the office
tower building, sky restaurants having afloor-to-floor height of more than 7.2 m
were planned for each of the three topmost floors. Because the building exterior is designed based on the underlying
concept of a vertical composition, it was
required for the exterior of the topmost
section to possess high transparency thatwould allow for a fine view. Accordingly, we proposed a framing structurein which diagonal kickers and horizontal trusses would be installed, thereby allowing the client’s wishes to be successfully put into effect. (Refer to Photo 2
and Fig. 4).
Fig. 3 Framing Model of Office Tower• Retail Building
The retail building is a nine-story aboveground structure with a height of about
57 m. It presents an image in which jewel boxes are piled in shifted forms ateach floor (Photo 3). The approximate
size of the floor plate is 66 m×50 m, anda moment frame steel structure was applied that adopts a basic module measuring more or less 11 m×8 m in conformity
with a floor-to-floor height of 6~7.2 m.

Photo 2 Erection of topmost section of office
tower*

Fig. 4 Framing of Topmost Section of
Office Tower

Truss
Diagonal
kickerHorizontal
truss

Photo 1 Erection of office tower*

Fig. 2 Image of Joining Together ofPalms to Express Thankfulness

Photo 3 Erection of retail building
11 Steel Construction Today & Tomorrow April 2018

The overhanging lengths that occur due
to the shifting of floor units at each floor
is about 10 m in maximum, and diverse
methods were effectively applied to install
the suspended frame using triangle-shaped
trusses, Vierendeel trusses or cantilevered
beams depending on the respective overhanging lengths. (Refer to Fig. 5)
For the 1~3 floors of the retail buildingthat connects with the office tower building, a structural form was devised in whichthese three floors are put onto the corbel
provided in the office tower and bearings
having a sliding mechanism were installedon the corbel. The plan for the exterior of
the retail building called for a structural system in which the entire building was covered by a screen of Taiwan’s national flower plum-blossom patterns (Photo 4), thatwas manufactured by three-dimensionally bending a stainless steel-formed material. As regards the framing that supports thecomplex exterior members, a stress analysis was made to examine its applicability.
• Cultural Building
The cultural building has three stories
aboveground and a height of about 25
m. It is composed of unique polyhedrons
having an octagonal plane shape. The
building is used as both an entrance to theoffice tower and an event hall. The roof
and exterior walls are composed of titaniFig. 5 Framing Model of Retail Building
Triangle-shaped truss

um panels. (Refer to Photo 5 and Fig. 6)
Users and visitors come up to the second floor by an escalator that is installedin the first-floor atrium hall. The second
floor connects to the office tower and also serves as an access way to the event
hall on the third floor.
The event hall on the third floor is a
30 m×28 m column-free space arranged
on top of the first-floor atrium hall. It was
examined whether or not the outer configuration with its unique architecturaldesign could be fused with the building
structure, and then we proposed a framing type in which the seismic load is dealt
with by using an outer shell in the longside direction and the installation of innercolumns is reduced to a minimum. The
upper chord of the triangle-shaped trusses
on the third floor functions as a structur-

al foundation of the outer shell, on which
parallel arch members sit in 3-m spacingin the short-side direction (Fig. 7).
In the underground space beneath thecultural building are located a large-size
bus parking lot and traffic lanes, and as aresult, arrangement of supporting points
for the superstructure were limited. Dueto these needs, the complex structure discussed above was adopted for the framingof the cultural building. Discussions on thepractical application of this complex structure were made between the local structural engineers and Mitsubishi Jisho Sekkei
to reconcile proposals and plans.
Acknowledgments
I would like to express my sincere gratitude to our client, Nan Shan Life Insurance Company Ltd., who gave us extensive guidance regarding the current
project, and also to Evergreen Consulting Engineering, Inc., who gave us kind
support. ￭*Photos by courtesy of:
Photo 1 by Fu Tsu Construction, Photos
2 and 6 by YKK-AP, Photo 4 by Kinzi

Photo 5 Erection of cultural building

Fig. 6 Image of Cultural Building
Serving also as Office Tower
Entrance

Note
The current article was prepared basedon the progress of the project as of November 2017.
Fig. 7 Framing Model of Cultural Building
Parallel arch member aligned
in 3-m spacing

Triangle-shaped truss

Vierendeel truss

Photo 4 Screen having plum-blossom
patterns*

Photo 6 Distant view of Taipei Nanshan Plaza from Elephant Mountain in Taipei*
April 2018 Steel Construction Today & Tomorrow 12

Feature Articles: Japanese Steel Construction Technologies (3)Tsubasa Bridge in Cambodia

by Masahiro Nomoto, Chodai Co., Ltd.
Project Outline
National Road No.1 (NR1) in Cambodia is a part of the Asian Highway andSouthern Economic Corridor which connects Ho Chi Minh City and Bangkok via
Phnom Penh. As the economy of the surrounding areas developed, traffic jams due
to increased traffic demand became a hugeproblem. Especially the Mekong Rivercrossing area was a traffic bottleneck because of the low capacity of the ferries
used to cross the river. Tsubasa Bridge wasthus constructed as a Japanese grant aid
project to alleviate this bottleneck. (Refer
to Figs. 1 and 2, Photo 1, Table 1)
This article describes the design characteristics and construction method of

the PC cable-stayed bridge, the main
bridge of the project.
Design Phase• Edge Girder Bridge
An edge girder was selected as the main
girder type for the PC cable-stayed bridgein consideration of the scale of the bridge(13.5 m effective road width).
Edge girders are more cost-effective
than box girders since they are easier toreduce the dead load resulting from theconcrete volume (Fig. 3 and Photo 2).
They are also superior in assuring quality in countries with less developed technology, because they enable easier formwork and bar arrangement work througha simpler girder designand shape.
Edge girders can beaffected by torsion flutter at low wind speeds
due to the shape of themain girder because of
their low torsion rigidity compared to box
girders. Therefore, windtunnel tests were con-ducted in order to determine a main girdercross-sectional shape with high wind resistance and stability.
• Wind Tunnel Tests
To select a cross-section for the main
girder with high wind resistance and staFig. 3 Edge Girder Dimensions
Total width 16980
Cable space 14500

Photo 2 Edge girderFig. 1 Location Map

Photo 1 Full view of Tsubasa Bridge

Phnom Phen

Table 1 Project Outline
Project length

5.500 km

Bridge type3-span continuous PC cable-stayed bridge

Foundation type

Hypostyle foundation

Spans

160 m+330 m+160 m

Bridge width13.500 m

Design velocity

80 km/hMekongRiver
East-West Economic Corridor
Southern Economic Corridor

Prey Veng City

KandalNeak Loeung

Neak Loeung

Fig. 2 General View of the Bridge

Shipping passage

Shipping passage

Clip pile

Shipping passage

Clip pile
Clip pile

13 Steel Construction Today & Tomorrow April 2018

Prey Veng

Clip pilebility, wind tunnel tests were conducted
not only for the original cross-section but
also for 3 other cross-sections with different fairings using 1/60 scale models(Table 2 and Photo 3).
In the experiment, a uniform windflow with −3, 0, and +3 degree angles ofattack was applied to the spring supported partial model with 2 degrees of freedom of vertical deflection and torsion.
Deflection vortex excitation and torsion flutter occurred on the original
cross-section with a −3 degree angle ofattack (downward wind direction). Although the amplitude of deflection vortex excitation was less than allowed, torsion flutter occurred at a wind speed of
44.0 m/s which is smaller than the verifying wind speed of 52.9 m/s. Therefore,
the same experiment was conducted withdifferent shapes of fairings and a (small)fairing was adopted which did not suffer from flutter at an 80 m/s wind speed
and showed little deflection vortex excitation. (Refer to Figs. 4, 5 and 6)• Stay Cables
Taking into account the benefit of windresistant stability, a parallel stay cablearrangement was adopted. Cables which
are vertically arranged in the cross-section help mitigate the sense of confinement that pedestrians may feel and also
ensure easier constructability during stay
cable installation.
The vertical spacing of the stay cables
is between 1.25 m and 2.3 m on the towers and 8 m on the concrete deck.
Non-grouting site assembly cables
were selected considering their advantages which include easy transportationand installation and reliable rust-proofing.

Table 2 Wind Tunnel Test Conditions

Fig. 4 Fairings for Wind Tunnel Testing

Structural damping ratio

0.02

Design velocity

U10=30 m/s

Degree of roughness

0.16

Girder altitude

45.8 mTarget wind velocity

38.3 m/s• Towers
The towers are H-shaped to conformwith the parallel out-plane arrangementof the stay cables (Fig. 7). An RC structure was adopted for the shafts which arealways under compression, while a PC
structure with a hollow cross-section was

Original
cross section

Fairing—
Upper 30 degrees

Fairing (large)

Fairing (small)

Photo 3 Wind tunnel test

adopted for the cross beams which connect the shafts.
The shaft cross-section and the shape ofthe cross beams and the top of the towers
were examined for their aesthetic qualities.
The stay cable anchorages are a separate type which makes maintenancework easier. U-shaped PC strands andPC bars were used to reinforce the anchorage zones (Fig. 8).
Construction Phase• Unexploded OrdnanceAlthough about 4,200 unexploded ordnances (UXOs) were removed with thecooperation of the Cambodian military
before the start of construction, an explosion still occurred during the constructionof the foundation piles of the cable-stayed
Fig. 7 Front View of H-shaped Tower

Fig. 6 Static Three-component Force Test Results

Fig. 5 Wind Speed-Amplitude Relation (Torsion −3 deg.)

April 2018 Steel Construction Today & Tomorrow 14

bridge. Luckily no one was hurt, but a reinvestigation and the adoption of necessary countermeasures led to a 4-monthsuspension of construction work. In orderto recover this delay and shorten the construction period, the methods described
below were adopted which enabled construction to be completed on time.
• Sliding Form and Prefab Construction
For tower construction, a jumping form
system with integrated formwork andscaffolding and prefabricated rebars was
adopted in order to save work and shorten

the construction period (Photos 4 and 5).
• Adoption of 8 m Blocks
8 m blocks were adopted with an underslung form traveler for the main girder
cantilever construction which enabled abasic construction cycle of 10 days (Photo 6 and Fig. 9). For this method, countermeasures such as prefabricated rebar forthe cross girders of the main girders weretaken (Photo 7). Counter weights were also applied on the opposite end of the cantilever in order to prevent an unbalanced
situation which was an adverse reaction
from the large-scale form traveler.

Photo 4 Jumping form system

Conclusion
The opening of Tsubasa Bridge shortened
the time needed to cross the river from 7-8hours in busy seasons to only a few minutes. The fact that the Asian Highway wasconnected by road had a big role in improving the economy and quality of life ofsurrounding areas. Thorough discussions
were held with the residents around theriver from the route selection stage and the
project was carefully planned to ensure thefull comprehension and acceptance of thevarious project stakeholders in line withJapan’s official ODA policy. ￭Photo 5 Prefab rebar for tower

Fig. 8 Stay Cable Anchorage Zone
Reinforcement U-shape
PC cable for T1

U-shape PC
tendon (2/row)

Number of PC
tendon

T

P
T

T
P

T

Photo 6 Form traveler for 8 m blocks

Reinforcement PC bar for T2

Fig. 9 Structural Drawing of Form Traveler
Block length = 8.0m

Launching hanger

Anchorage for temporary
tensioning work

Bracket for temporary tensioning work
15 Steel Construction Today & Tomorrow April 2018

Casting hanger
KickerJacking system for traveling

Photo 7 Prefab rebars for cross beam

Special Article: Stainless Steel

Lean Duplex Stainless Steel for
Selective Water Intake Facility

by Yasuhiro Tsuruga and Noriaki Fukushima, IHI Infrastructure Systems Co., Ltd.
Mitigation of Burdens and Costs
The Futase Dam is a multipurpose dam
constructed in 1961 with the aim of controlling floods, securing agricultural irrigation water and operating a local government-owned hydropower station. In
order to reduce the discharge of cold andturbid water from the dam into the river below, a selective water intake facility was additionally installed at the inflow section of the water conduit pipe forpower generation.
Because of the additional installation
at the existing gravity arch dam, a selective water intake facility of the multi-

Table 1 Outline of Selective Water Intake Facility of Futase Dam
Order placement

Kanto Regional Development Bureau, Ministry of Land, Infrastructure,
Transport and Tourism

Project nameInstallation of selective water intake facility at Futase Dam

Facility

Selective water intake facility of the multi-stage rubber membrane type×1
Water intake amount: 7.5 m3/s; number of stage: 8; water intake range: 40 m

Installation site

Ootaki, Chichibu, Saitama Pref.

Construction term January 2014~June 2016
Structural
materials applied

SUS304, SUS821L1stage rubber membrane type was adopted with the aim of mitigating the burden
placed on the existing dam body and re-Fig. 1 Drawing of Entire Dam Structure (seen from upstream side)
Crest gate

(Constructed by IHI in 1961)

Selective water
intake facility(Current project)

Conduit gate

Discharge pipe for irrigation(water intake for agricultural use)
(Constructed by IHI in 1961)

Fig. 2 Overview of Selective Water Intake Facility
Flying deck

Lifting device
Movableframe
Impervious
membrane/
Movable frame

Flying deck

Flying deck
receiving table
Upper screen
Guiderail frame

Lifting device
Guiderail
Water intake
cover plate

Water
intake screen

Flying deck
receiving table
Guiderail frame

ducing costs. Fig. 1 shows an entire dam
body, and Fig. 2 an overview of the selective water intake facility.
Outline of the Selective Water Intake Facility
Table 1 shows an outline of the selective
water intake facility at Futase Dam. The
selective water intake facility is composed mainly of an expansion/contraction gate leaf (impervious membrane,
movable frame), a guiderail serving as
the lifting guide for the gate leaf, a wirerope-type lifting device, and a flying
deck. The gate leaf is supported by thelifting device, and the lifting device issupported by the existing dam body via
the flying deck.
The movable frame of the gate leaf is
a welded structure. Because of restrictions imposed on its transportation, themovable frame was divided into several
blocks, which were carried into the site
and assembled by means of on-site welding. Fig. 3 shows a three-dimensional
drawing of the movable frame.
Fig. 3 Three-dimensional Drawing ofMovable Frame

Guiderail
receiving table

Upper screen
Shelter
Frame
receivingtable

Shelter
Shelter frame

Shelter frame
Shelter
receivingtable

Shelter
receiving
table(Full expansion state)(Full contraction state)
April 2018 Steel Construction Today & Tomorrow 16

Features of Lean Duplex StainlessSteel
The application of duplex stainless is
growing worldwide. In order to incorporate the attainments obtained in thedevelopment of the new duplex stainless steel, lean duplex stainless steel wasstandardized in the Japanese Industrial
Standards in 2015. Currently two steel
grades, SUS821L1 and SUS323L, areregistered as lean duplex stainless steel
in the Standards.
In comparison with the conventional
duplex stainless steel SUS329J4L, lean
duplex stainless steel is manufactured bysuppressing the addition of the expensive
elements Ni and Mo and adding N to theextent that it does not affect weldability. The end result thus attained for lean
duplex stainless steel is the realization ofhigh strength, which is about twice thatof SUS304, and economic advantages,
corrosion resistance and weldability similar to those of SUS304. Table 2 shows
the main composition and mechanicalproperties of lean duplex stainless steel.
Application of Lean Duplex Stainless SteelThe gate leaf of the selective water intake facility constantly remains in water. Accordingly, from the aspect of securing corrosion resistance and reducing
the lifecycle cost of the selective water
intake facility, it has recently becomecommon practice to adopt stainless steel
for such an application. In order to further reduce the burden placed on theexisting dam body, lean duplex stainless steel SUS821L1 that has a strength
about twice that of SUS304 and serves asa substitute for SUS304 was adopted forthe movable frame of the gate leaf, which
successfully led to a further reduction of
the structural weight of the gate leaf.
In adopting SUS821L1 for the movable frame of the gate leaf, both factory and on-site welding tests were carriedout to confirm its weldability and the validity of the welding conditions. In addition, corrosion resistance tests were
implemented for welds to confirm thatthe corrosion resistance of the welds of
SUS821L1 is similar to or higher thanthat of SUS304.
Photo 1 shows the trial assembly ofgate leaf (movable frame) for which
SUS821L1 is adopted, and Photo 2 theinstallation of gate leaf.

Low Burdens on and Reduced
Expense of Civil Engineering
Structures
The structural weight of the movable
frame could be reduced by about 20% byadopting SUS821L1 lean duplex stainless steel, and the lightweight structure
thus attained has led to a reduction of theburden placed on the existing dam body.
Photo 3 shows the full view of the Futase
Dam after completion of the selective
water intake facility.
The development of lean duplex stainless steel, SUS821L1 and SUS323L, hasallowed it to be used as a substitute forconventional stainless steel, SUS304 and
SUS316, and in the installation of lightweight dam structures as well.
In the construction of gate facilities,
because these lightweight gate leaves facilitate not only a reduction of the capac-

ity of hoist and its downsizing but also
mitigate the burden placed on dam bodies and other civil engineering structures,in recent years SUS821L1 and SUS323L
are increasingly being applied in the construction of gate facilities on rivers and indams. In the future, it is forecasted that theneed will further grow for the effective
utilization of existing infrastructures suchas the redevelopment of existing dams,
measures to cope with the superannuationof existing infrastructures and measures
to enhance their seismic resistance.
Given these circumstances, expectations are high for the use of lean duplex stainless steel, SUS821L1 and
SUS323L, as structural materials thatwill contribute towards the reduction of
public works expenditures on such items
as gate facilities and other civil engineering structures. ￭Table 2 Main Compositions and Mechanical Properties of Stainless Steel
Kind

Steel grade

Main compositions(mass %)

0.2% offset yieldstrength (N/mm2)

Tensile strength(N/mm2)

Lean duplex
stainless steel

SUS821L1

21Cr-2Ni-0.17N

≧400

≧600

SUS323L

23Cr-4Ni-0.15N

≧400

≧600

SUS329J4L

25Cr-7Ni-3Mo

≧450

≧620

SUS30418Cr-8Ni

≧205

≧520

SUS316L

18Cr-12Ni-2Mo

≧175

≧480

Duplexstainless steel
Austenitic
stainless steel

Photo 1 Factory temporary assembly of gate leaf
(movable frame) employing SUS821L1

Photo 2 Installation of gate leaf (movable frame)

Photo 3 Full view of Futase Dam after completion of selective water intake facility
17 Steel Construction Today & Tomorrow April 2018

JSSC International Events

PSSC2019 to Be Held in JapanThe Pacific Council of Structural Steel
Associations (PCSSA) is an organization in which the Japanese Society of
Steel Construction and other steel construction-related associations of the Pacific rim participate. PCSSA not only
serves as a site for promoting exchanges among its participating organizations
and solving common tasks but also functions as a nucleus for promoting the Pacific Structural Steel Conference (PSSC)
that is hosted every three years on an alternating basis among the participating
nations.
The first PSSC was held in New Zealand in 1986 followed by ten subsequent
PSSCs in other countries (see the table atright). The previous 11th PSSC was heldin Shanghai, China in October 2016, andon that occasion with representatives
from various countries, it was decided
to hold the 12th PSSC in Japan in 2019.
In this connection, the ceremony to deliver the PSSC flag from China to Japanwas held (see the photo). The 12th conference will be the first one held in Japan
since the third one 27 years ago in 1992.
According to the record, the participating counties numbered seven in 1992,

but in recent conferences the number has
increased to 11 (see the table at right).
In order to take all possible measures
for a successful 12th PSSC, the Japanese Society of Steel Construction established the Specialized Committee for
Arranging PSSC2019 which is chaired
Outline of Pacific Structural Steel
Conferences (PSSC)
Year

PSSC

Host country

1986

1st

New Zealand

1989

2nd

Australia

1992

3rd

Japan (Tokyo)

1995

4th

Singapore

1998

5th

Korea (Seoul)

2001

6th

China (Beijing)

2004

7th

USA (Long Beach)

2007

8th

New Zealand (Taupo)

2010

9th

China (Beijing)

2013

10th

Singapore

2016

11th

China (Shanghai)

2019

12th

Japan (Tokyo); Planned

Ceremony to deliver the PSSC flag from China to Japan

by JSSC President Yozo Fujino and has
started preparations for the PSSC2019
that is planned for November 2019 in
Tokyo. In 2020, the Tokyo Olympic andParalympic Games will be held. In lightof this, PSSC2019 is expected to present
a good opportunity for the Japanese steel
construction-related companies to disseminate their world-class technologies
and for its young researchers and engineers to deepen exchanges with overseas
researchers and engineers.
Eleven Organizations in Eleven
Participating Countries• American Institute of Steel Construction(AISC)• Australian Institute of Steel Construction(AISC)• Canadian Institute of Steel Construction(CISC)• Chilean Steel Institute• China Steel Construction Society• Japanese Society of Steel Construction(JSSC)• Korean Society of Steel Construction(KSSC)• Mexican Institute of Steel Construction• Malaysian Structural Steel Association• Steel Construction New Zealand• Singapore Structural Steel Society(SSSS)

Construction is proceeding of the New National Stadium for the Tokyo 2020 Olympic and Paralympic
Games (as of February 2018).

Courtesy of JSC

2017 China-Japan-Korea Tall Building Forum in Chongqing, China
The 2017 China-Japan-Korea Tall Building Forum was held on September 21
and 22, 2017 at The Westin Chongqing
Liberation Square in Chongqing, China.
The current forum was held jointly withother tall building-related symposiums
under the common name of 2017 Super Tall Building Industry International
Summit. The total participants numberednearly 500 thereby resulting in a largescale international conference.
In the day-and-a-half forum, diverse
kinds of lectures concerning tall buildings were delivered by 28 lecturers suchas land developers, architects and structural engineers from Japan, China, Korea, the US and Russia.
A total of 12 structural engineers fromJapan, with Chairman Akira Wada of the
CTBUH Japan Structures Committee of
the Japanese Society of Steel Construction as their representative, participated in the forum. Of these engineers, fourdelivered lectures concerning the structural design of seismic-isolation and response-control tall buildings and a rapid(continued overleaf )April 2018 Steel Construction Today & Tomorrow 18

diagnosis system of tall buildings during
earthquakes to demonstrate advanced
wind- and seismic-resistant technologies
in the field of tall building constructionin Japan.
In the afternoon of the second day of
the forum, a Technical Tour was madeto the site of Raffles City Chongqingthat was under construction in Chaotianmen, Chongqing.
Raffles City Chongqing is a gigantic-

scale development project that aims toconstruct complex facilities (hotel, residence, office and retail) with a total floorarea of 1.13 million m2. The project will
include eight tall buildings composed of
two north towers that are 350 m high andsix south towers with a height of 250 m.
On top of the four south towers, a 300
m-long observation deck will connect
the four towers, which is seismically isolated via friction pendulum bearings. Di-

Lecture delivery from Japanverse architecturally and structurally
unique features are incorporated in the
project. Currently, the building framing
work is proceeding with a targeted completion date in 2019. More than 100 forum participants visited to the construction site.
(Prepared by Masayoshi Nakai, Director, CTBUH Japan Structures Committee of JSSC)

Raffles City Chongqing project underway

Message from International Committee Chairman

Towards Further Development of Steel Construction
Technologies

Hiroshi Katsuchi, Chairman, International
Committee of JSSC (Professor, Yokohama
National University)

The Japanese Societyof Steel Construction(JSSC) has conducted a wide range ofactivities in the formof surveys, researchand technological development aimed at promoting the spreadof steel construction and at improving associated technologies, and at the sametime it has extended cooperation to related
overseas organizations. Aimed at spreading the steel construction technologies ofJapan to developing overseas markets,

the International Committee of JSSC
was responsible for editing Issue No. 53
of Steel Construction Today & Tomorrow, a special issue for JSSC.
Issue No. 53 firstly introduces the
JSSC Commendations for Outstanding
Achievements in 2017-JSSC Awards,
Outstanding Achievement Awards andThesis Awards. In addition, this issue
features outstanding Japanese steel construction technologies utilized in overseas construction projects-Passenger
Terminal of the New Doha International
Airport, the Taipei Nanshan Plaza project in Taiwan and the Tsubasa Bridge in
Cambodia. In addition, a report on theapplication of new lean duplex stainless

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
3F Aminosan Kaikan Building, 3-15-8 Nihonbashi, Chuo-ku, Tokyo 103-0027, Japan
Phone: 81-3-3516-2151 Fax: 81-3-3516-2152
URL http://www.jssc.or.jp/english/index.html

steel to the water intake facility of theFutase Dam is introduced.
Regarding our international events in
2017, two reports are inserted-the establishment of the special committee forthe 12th Pacific Structural Steel Conference (PSSC2019) planned for Tokyo, Japan in 2019, and the 2017 China-Japan-Korea Tall Building Forum inChongqing, China held in September
2017.
Finally, we would like everyone tobe continuously aware of the activities
of JSSC and we would also like to hear
your opinions at any time.

© 2018 The Japan Iron and Steel Federation
Edited byCommittee on Overseas Market Promotion, The Japan Iron and Steel Federation
Chairman (Editor): Hiroyuki Tanaka
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.