No. 44 April 2015

STEEL CONSTRUCTIONTODAY & TOMORROW

http://www.jisf.or.jp/en/activity/sctt/index.html【 s a i 】
“再 (sai)” in Japanese, or “re-, again” in English

Issue No. 44 highlights demolition technologies for high-risebuildings and bridges. The basic aim of demolition or
dismantling is to renew, rebuild or reuse old structures.
Special Issue: Japanese Society of Steel Construction

Commendations for Outstanding Achievements in 2014
1 ABENO HARUKASSuper Tall
Compact City

3 GINZA KABUKIZA
4 Akasaka(courtesy: SHOCHIKU

Center Building

5 Assessment of Equivalent Stiffness for Elasto-plastic Buckling Loadof H-shape; Relation between Seismic and Tsunami-resistant Designs

6 Effects of Weld Toe Shape on Brittle Fracture Occurrences;Hydrogen Uptake Affecting Delayed Fracture of High-strength Bolts

Special Feature: Demolition of High-rise Buildings and Bridges
7 Demolition of Steel Structures
Published Jointly by

9 Cut and Take Down Demolition Method 10 Upper-floor Closure-type Demolition Method
11 Cube Cut Demolition Method

The Japan Iron and Steel Federation

8 Closed Demolition Method
12 Reverse Construction Demolition Method

13 Dismantling Methods for Steel Bridges 14 Replacement of Railway Bridges in Vietnam
16 Remodeling of Highway Bridge on Metropolitan Expressway

Japanese Society of Steel Construction

18 Messages from New JSSC President and Committee Chairman・JSSC Operations

Commendations for Outstanding Achievements in 2014-JSSC Award

Big⇔ Compact

ABENO HARUKAS Super Tall Compact City
Prize winners: Kiyoaki Hirakawa, Takenaka Corporation; and four other companies
ABENO HARUKAS is Japan’s tallest skyscraper, standing at 300 meters, which wascompleted in March 2014 (Fig. 1). Thisbuilding is a superhigh-rise vertical citywith the gross floor area of approx. 212,000
square meters. Rising 60 stories above theground and 5 underground stories, this tower incorporates diverse functions: a terminal
station, a department store, an art museum,
offices, a hotel, an observatory, parking spaces and more. No other building of this scale
has been built above a station in any placethroughout the world.

vertical voids.
The mid-rise floor void has outriggers
on the 15th and 37th floors and two 2-story
braced outriggers located between them; oneon the 25th floor and the other on the 31st
floor. These outriggers suppress the deformations equivalent to the antinodes in higher vibration modes and work effectively to reduce
the responses throughout the whole building.
Fig. 1 Frame Model

Special Features of ABENO HARUKASABENO HARUKAS (“HARUKAS”) stands
out from other general skyscrapers becauseof the following three noteworthy features:-This is a vertical city type skyscraper beyond the bounds of a mixed-use complex;-The existing building was reconstructed
into this skyscraper; and-A high-grade vibration-damped building was constructed in Japan, one of theworld’s most earthquake and typhoon-ridden countries.

1 Steel Construction Today & Tomorrow April 2015

into Skyscraper
HARUKAS is a reconstructed skyscraper above the terminal station used by Osaka’s third largest number of passengers. Thisbuilding is adjacent in the east to the existinghigh-rise department store which has been inbusiness, connected to the low-rise department store of HARUKAS through a large
void space.
Structurally, this void space serves as an
expansion joint that will allow for the twobuildings to move differently in case of earthquake.

• High-grade Vibration-damped Build-

ing Constructed in Japan, One of
the World’s Most Earthquake- andTyphoon-ridden Countries
Japan belongs to the region where both thedesign seismic and wind loads are the largest,and it would be no exaggeration to say thatJapan is number one in the world in terms of
the severity of disturbance.
Under the above conditions of external
forces, we established the design criteria of
HARUKAS to upgrade those of normal skyscrapers by one grade for this building, by allowing no member of this building to be plastically deformed against any Level-2 external
force.

• Vertical City Type Skyscraper 		beyond Bounds of Mixed-use 		ComplexHARUKAS was so designed as to maximize
the performances of a terminal station andmany other uses and functions, which were
shifted with different footprints and stacked.
HARUKAS is outstanding not only in thatthe activities of the functions in the city are
vigorous and attractive but also in that the infrastructure through which they achieve theirobjectives is regarded as important, and all its
factors are functionally, environmentally andstructurally linked to one another.
Structurally, the vertically located voids
are interlinked to the horizontal outriggers,which form a Linked Void Structure.
For the low-rise floors, vibration dampers are concentrated to absorb the energycaught by large shear deformation components, where the stairwells in the back-ofhouse area of the department store are laidout at the four corners of planes and used as• Existing Building Reconstructed- Signature Building of JapanThe Linked Void Structure enabled us to realize ABENO HARUKAS that meets the architectural, environmental and structural requirements of the different approaches fromthose for the conventional skyscrapers andthus to create a worldwide recognizable signature building of Japan.

The high-rise floor void serves as a climbing passage for the cool air taken in from the37th-floor outrigger and has a role of expanding the stance of the high-rise in a lateral direction.

Construction of ABENO HARUKASThe project site is situated in proximity tofive conventional railway lines including two
subway lines, and adjacent in the east to themain building of the department store in thisnew tower, which has been open for business. The Osaka Abenobashi Station used to
be standing on the ground floor of the old department-store building reconstructed in thisproject. Therefore, construction of this tow-

er required switchovers of passenger circulations while demolishing the old departmentstore building.

• Comprehensive Temporary Work

Planning
Under such circumstances, it was a criticalissue to secure the building materials carry-in/-out routes and construction yards. We
brought the construction of some areas of thesecond and third floors into a later process
and thus created a space that allowed a freetraffic of large vehicles and heavy machines
in order to solve the above issues.
Simultaneously, we separated the construction yard into the structural steel transport circulation route and excavated earth
carry-out yard on the ground floor and theconcrete mixer truck parking yard on thefirst basement floor.
During the erection of the officeand hotel components, the setback
rooftops of the 16th and 38th floor
levels were used as the second andthird construction yards for such purposes as temporary storage of members
for the upper floor levels.

to prove the validity of the construction management approach that we applied to thisproject. On the other hand, the maximum deflection at the tip of the overhang was 9 mm,
which was less than the target control value
and enabled us to achieve extremely high accuracy of steel installation.

• Outline of Underground WorkWe needed to excavate down to as deep as 30
meters below the surface of the ground, sur-Fig. 2 Under Construction• Outline of Ground Work

Our top-priority issue was to ensure the accuracy of the special-shaped steel structure.
The building inclination of the officecomponent turned out to be larger than thoseof the department store and hotel components, which was affected by the hotel component occupying
only a half of the officecomponent in the south
and the higher axial rigidity of the long columns
in the north of the officecomponent. With the hotel component built on it, therelative displacement was approx.
30 mm, compared with the data acquired when the 38th floor was constructed.
In accordance with the above analysis
result, we fabricated steel columns on the office floors so that they may extend by 4 mm
to 2 mm per erection unit. We also erected thestructure by inclining the building itself byapprox. 4 mm per erection unit to the north,based on the GPS measurements.
The maximum inclination of the building
top based on the GPS measurements was 114
mm, and the vertical accuracy was 1/2632,
which were within the scope of allowable
control values. Consequently, we were able

rounded by five conventional railway lines.
We used the high-rigidity TSW (Takenaka
Soilcement Wall) Construction Method, oneof our technologies, to enable this excavation
to a great depth.
The TSW Method uses soil cement madeof excavated soil of the class and particle

size adjusted on the ground, instead of concrete, which was placed into the excavated groove through a tremie tube. A continuous wall formed of this soil cement served
as a temporary earth retaining wall and cutoff wall. Since this method recycles the excavated soil, it not only suppresses the generation of construction byproducts but also
contributes to reducing the emission of exhaust gases from surplus soil transportation
vehicles. Thus the TSW Method is an environmentally-friendly method. For the core ofthis earth retaining wall, such material as Hshaped steel is inserted as in a soil cement
column row wall. Moreover, this wall is evaluated as a hybrid basement wall with permanent piles, which reduces the numberof outer peripheral piles, consequently
shortening the construction period andcutting down the underground obstacle removal cost.
The piles to support a 300 meter high skyscraper were in-situ concretebelled piles (Takenaka TMB Piles) with shaft
diameters of 2,300 - 2,500 mm, expandedbottom diameters of tips that were 3,400 4,200 mm and pile tip level of approx. 73 meters below the ground. For the underground
piled columns, extremely thick materials (upto 90 mm) were used to support high axial
forces, and their weights were close to 100
tons. The underground piled columns wereapprox. 32 meters long due to the deep underground space.
In recent years, there has been a tendencyof driving very strong piles with small-diameter shaft parts in economic and environmental considerations. Especially if pre-erectionof underground piled columns is intended,
it is foreseen that it will be difficult to secure clearances of control fixtures
and tremie tubes. Against this background, we consider that there
will be an increase of needs
for the construction methods
applied to this project.
- Tallest Building in Japan
This building not only is a skyscraper witha deep underground space but also was extremely difficult to build due to the locationand other restrictions. Therefore, we have improved and developed a wide variety of construction methods. Currently, Japan’s tallest
vertical city is soaring in the land of Abeno,
Osaka.
￭

April 2015 Steel Construction Today & Tomorrow 2

-Outstanding Achievement Award

GINZA KABUKIZA

Prize winners: A Design Joint Venture by Mitsubishi Jisho Sekkei Inc. and Kengo Kuma andAssociates, and Shimizu Corporation
In order to support 23 stories of office space
above the Kabukiza Theater, which has alarge void in plan, two 13 m-deep Megatrusses, spanning 38.4 m, are installed at the
fifth and sixth floors of the building.
Each Mega-truss carries five columns, andthe total long-term axial load of the columns
is about 9,000 tons. A high level of safety isdesigned into the Mega-truss by ensuring thatthe stresses generated in truss members areless than the allowable short-term stresses
even under combined loading conditions that
include the effects of vertical seismic motion
during major earthquakes.
The following three goals were set as design targets in order to achieve not only highseismic safety of the building but a rationalframe design for the standard floors above
the Mega-truss.
(Courtesy: Shochiku Co., Ltd. and Kabuki-za Co., Ltd.)• Eliminate excessive additional stress imposedon the upper structure due to the Vierendeel
effect that is caused by vertical bending of
the Mega-truss, if normal construction procedures were adopted; and achieve rationalframe design for the standard floors• Avoid redistribution of the vertical loadingin the event that the upper floors’ Vierendeel structure became plastic during a major
earthquake; and to transfer the long-term axial
loading of the columns to the Mega-truss reliably, hence achieve a highly stable structure• Prevent harmful deformations in the façade,etc. associated with construction of the up-

per floors
As a result of careful study, it was decided early in the design stage to control vertical deflections at the seventh floor where columns connect to the top of the Mega-truss
during construction. Also, it was decided tojack up the columns to match the bending
produced by construction of the upper floors
in order to maintain a horizontal alignment of
the beams at the eighth floor.
A high accuracy of ±2 mm was achievedto the target vertical deflection and the stressin the upper-floor structure was within thedesign target.
￭

Typical Floor Plan

7th Floor Plan (Mega-truss Floor)

Buckling-restrained
brace

Column supported
by Mega-truss

Oil Damper
Y7
Y5

Mega-truss

Oil Damper
Y7
Y5

X3

X3 Elevation

North-side truss

X3

Y7 Elevation
Buckling-restrainedbrace

Oil Damper

Buckling-restrainedbrace

Oil Damper

Mega-truss

Overall view

▽7FL
Wall beam▽GL

Mega-truss

3 Steel Construction Today & Tomorrow April 2015

▽GL

-Outstanding Achievement Award

Akasaka Center Building

Prize winners: Mikiko Kato, Noriaki Sato, Shohei Yamada and Mikio Yoshizawa, Nikken Sekkei Ltd.,and Kazuo Tamura, Kajima Corporation
The Akasaka Center Building featuring steelframe eaves is located in an area of abundant
greenery in downtown Tokyo. The area is also noted as a historical and cultural site andlies adjacent to the Akasaka Goyochi (site ofmany imperial facilities) and Toyokawa Inari(a famous Buddhist temple).
Two notable features of the building are:an L-shaped configuration of the office space
to ensure a fine view from the offices and theuse of external peripheral framing columns
to allow for the steel-frame eaves. The design concept relies on a “thoroughgoing useof steel,” thereby leading to an extensive useof steel products for not only the structuralmembers but also exterior and interior components.
The building, with a height of 100 m, isa steel-frame structure in which buckling-re-straint braces have been adopted as the response-control members. The maximum
span between columns is 24.6 m. Among the
adopted column members are: 1,400 mm-diameter round steel tube columns that are arranged in the center of the building where theL-shaped office space is located, 900 mm-diameter round steel tube columns around thebuilding periphery, and 1,000 mm square
steel tube columns at the building’s core. The
strength rating of these columns ranges from490 N/mm2 to 590 N/mm2, and all the members are concrete-filled steel tubes (CFT). A
column-free structural plan is adopted for thebuilding’s corners to make fine, uninterrupted views available. The adopted girders are
H shapes having a depth of 1 m and strength
ratings of either 490 N/mm2 or 550 N/mm2.
The exterior cladding for the columns andAppearance

girders are hot-dip galvanized/phosphatetreated (ZnP) steel sheets that feature a beautiful spangled pattern. Because fire protection is provided on the heavy-duty corrosion
protection-coated steel products and because
ZnP steel sheet cladding is used as the finishing members, corrosion-protection maintenance is not required. Fine-surface ZnP steel
sheets are also used as interior members forthe steel ceilings and glass mullions in theentrance hall and for the exterior steel-frame
eaves.
In this way, at the Akasaka Center Building, “steel architecture” has been realizedthat thoroughly utilizes steel frames for thebuilding structure as well as the decorative
members.
￭

Entrance hallPlan at Standard Floor

Floor Plan at Standard Floor

Framing Elevation

Brace
truss

Steel tube 900φ

24.6 mSquare tube 1000□
Steel tube 1400φ
100 m

20.4 mBrace

10.8 m7.2 m

April 2015 Steel Construction Today & Tomorrow 4

-Thesis Award
Assessment of Equivalent Stiffness for Elasto-plastic Buckling Load of Eccentric
Stiffening H-shape Compression Members with Different Stiffening Types
Prize winner: Yuuki Yoshino (Representative), Tohoku University
Yuuki Yoshino
2012: Graduated from Doctoral
Course, Graduate Schoolof Nagasaki University
2012: Entered Doctoral
Course, Graduate
School of Tohoku University
2015: Expected to graduate from Doctoral Course,
Graduate School of Tohoku University

The elasto-plastic buckling strength of an Hshape compression member to which a nonstructural member is attached (Fig. 1) differs in the elastic and inelastic ranges. In
cases when the effect of different eccentric
stiffeners is equally assessed, it has become
possible to efficiently design eccentricallystiffened compression members in a spacestructure.
In the paper, a comparison is made of theelasto-plastic buckling properties of H-shapecompression members between eccentric
stiffening at the member center (Type A) andcontinuously eccentric stiffening (Type B).
When an equivalent stiffness curve (Fig.
2) is adopted that is obtained as the ratio of
the horizontal stiffness ratio AKu/AKu0 of TypeA on the horizontal line to the horizontal
stiffness ratio BKu’/BKu0 of Type B on the verFig. 1 Horizontal and Rotational Stiffness of Non-structural Member
for Steel-frame Roof Member
Non-structuralmemberslaP1

Non-structuralmembers

P2
EA, EI

P1
P2
l'

P1
P2

Type A

P1

Type B

P2

tical line, an elasto-plastic buckling strength
can be found that is equal even in H-shapecompression members having different stiffening types.
￭
Fig. 2 Assessment of Equivalent Stiffness in Continuous Stiffening
K'u/BKu0

B

5

Equivalent stiffness
0.5Est Est 1.5Est

4H-500×250× 9 ×16
H-294×200× 8 ×12
H-300×300× 10 ×15

3Equivalent
stiffness curve

2
1
0

0

1

2

3

Ku /B Ku0

B

5 (=2AKu /AKu0 )4

Relationship between Seismic Design and Tsunami-resistant Design for
Steel Structures
Prize winner: Fuminobu Ozaki, Nagoya University
Fuminobu Ozaki
2003: Graduated from Graduate
School of Engineering
2007: Entered Nippon SteelCorporation (Steel Research Laboratories)
2013: Associate Professor, Graduate School ofEnvironmental Studies, Nagoya University

The main objective of the paper is to comprehensively clarify the relationship between
seismic design and tsunami-resistant design
for steel structures.
The relation between seismic resistanceand tsunami resistance was quantitatively assessed by applying seismic design (retained
horizontal strength calculation) to a simply
modeled steel structure model (Fig. 1) and byworking the tsunami wave force of a tsunamiresistant design on the model. It was clarified
in the assessment that there is a strong correlation between tsunami inundation depth andhorizontal load-carrying capacity of a structure estimated by the seismic design (Fig. 2),
which led to the strong recognition of the importance of seismic reinforcement for tsunami evacuation buildings constructed in con5 Steel Construction Today & Tomorrow April 2015

formance with the former seismic codes.
Seismic reinforcement is an approach that
can improve not only seismic resistance but
also tsunami wave resistance. On the other hand, even when a building is constructedconforming to the new seismic codes, there
are cases in which tsunami resistance drops
depending on the tsunami inundation depth.

Fig. 1 Simple Assessment Model ofSteel Structure

Q tf3

Tsunamiwave forceah

Q tf 2

Q tf 1

It was thus confirmed in the paper that tsunami-resistant reinforcement will be required inorder to separately provide for buildings constructed based on the new seismic code. ￭Fig. 2 Relation between Seismic Resistance Allowance and Tsunami Inundation Depth
Seismic resistance allowance(A ratio of horizontal
load-carrying capacity tonecessary horizontal
load-carrying capacity) β i
4
3.5
3
2.5
2
1.5
1
0.5
0

Opening
coefﬁcient
α = 0.9

10-story structure
Tsunami wave force
working surface 18 m

α = 0.7

Simple assessment
equation proposedin the paper

0

2

4

6

8

Need for seismic
reinforcement

10

12

14

Tsunami inundation depth h [m]Effects of Weld Toe Shape on Critical Condition of Brittle Fracture Occurrence during Earthquakes
Prize winner: Hiroshi Tamura, Associate Professor, Tokyo Institute of Technology
2012: Finished Doctoral Course,
Graduate School of Yokohama National University
2012: Associate Professor,
Graduate School of Engineering, Tohoku University
2014: Associate Professor, Graduate Schoolof Engineering & School of Engineering, Tokyo Institute of Technology

The brittle fracture that occurred in the
Northridge Earthquake and the Great Hanshin Earthquake caused fatal damage that exceeded the design expectations in many steel

structures. Brittle fracture of this kind is likely to break out from an initial shallow crackthat is 1 mm or less in depth that occurs in
the weld surface, and thus it was consideredthat the conventional brittle fracture condition cannot be applied to that fracture due tothe effect of the weld shape.
Given such situations, in the current research, examination was made of a test specimen that can reproduce the effect of the weld
toe shape of practical structures, and the effect of the weld toe shape working on thebrittle fracture occurrence limit on the crack
tip was assessed by means of a low-tem-

perature fracture test and an analysis of local stress on the crack tip. As a result, it wasclarified that the critical Weibull stress occurring at the time of brittle fracture propagationfrom a shallow crack depends on the crack
depth and the weld toe radius.
￭Fig. 2 Effect of Initial Crack Depth Foundin Critical Weibull Stress during
Brittle Fracture Propagation
2000
［MPa］

Hiroshi Tamura

20
10

120

Enlargement ofnotch section
R=0.5

10

Weibull stressFig. 1 Test Specimen for Examining the Occurrence Limit of Brittle Fracturefrom Shallow Initial Crack
20
120

1500
1000
500
0
0.0

Enlargement ofnotch section
1.0

Crack
(a) Notch radius: 0.5 mm

Notch radius 0.5mm
Notch radius 5mm
Notch radius 0.5mm (estimated)
Notch radius 5mm (estimated)

R=5.0
1.0

Crack
(b) Notch radius: 5.0 mm

0.5 1.0 1.5 2.0 2.5
Initial crack depth ［mm］

Unit (mm)Stochastic Evaluation of Hydrogen Uptake Affecting the Delayed Fracture of High-strength Bolts
Prize winners: Kazumi Matsuoka, Nobuyoshi Uno, Eiji Akiyama, Yukito Hagihara, Shinsaku
Matsuyama, Hiroaki Harada
1978: Finished graduate
school of engineering,Osaka University
1978: Entered Nippon SteelCorp.
2005: Finished Doctor Course of engineering,Osaka University

In evaluating the delayed fracture performanceof high-strength bolts, it is necessary to settle
two characteristic values: the local critical hydrogen concentrating of bolt HC* and the local
entry-hydrogen concentration of bolt HE*. In
the paper, the estimation was made of a pH level that drops in a rust film solution, which is required to calculate HE*. The approach applied
covers the following flow (Fig. 1).
(1) The accumulated fracture rate data of highstrength bolt, Pf, was obtained from a longterm 10-year exposure test conducted on 750
actual bolts.
(2) The statistical data was obtained by meansof a CSRT test that was developed by Hagihara et. al. and acquires the local critical hy-

drogen concentration HC*.
(3) A reliability analysis was applied to (1) and(2) above.
(4) The probability distribution of local entryhydrogen concentration HE* was determinedby means of reverse analysis. Then, an analysis was made by comparing the probabilistic distribution with the controlled-pH solution immersion test results.
(5) Finally, it was concluded that the most appropriate pH level that drops in an outdoor rustfilm solution is slightly lower than pH 2. ￭Fig. 2 Probability Density Function of
Entry-Hydrogen Concentration
HE of Bolt Steel

Probability density function f(x)Kazumi Matsuoka

Fig. 1 Analysis Flow of This Study(2) Strength: Local critical hydrogen concentration Hc*( Probability distribution is obtained by CSRT )(3)Reliability analysis of delayed facture
Z=Hc*/He* , Z<1 : Fracture

14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
0.0

0.1

0.2

0.3

0.4

Entry hydrogen Concentration HE(wppm)(4)Force: Local entry-hydrogenconcentration He*( Probability distribution is obtained byreverse analysis )Comparison(1) Fracture probability: Accumulated fracture rate Pf(obtained by log-term exposure test)(5) Extraction of corrosion
test pH

April 2015 Steel Construction Today & Tomorrow 6

Special Feature: Demolition of High-rise Buildings and Bridges

Demolition of Steel Structures
In recent years, global environmental issues
have taken on added importance. In this regard, the demolition of buildings and bridge
structures is attracting considerable attention.
Demolition is completely different from destruction and may appropriately be conceivedof as preparatory for the establishment of recycling-oriented societies (societies with areduced environmental burden) and as promoting recycling and reuse.
Emerging Needs for Restructuring ofSuperannuating Social Infrastructure
In Japan, societal needs are changing and avariety of structures and social infrastructures that support urban functions are becoming superannuated and are in need of reinforced disaster-prevention capabilities. Thisrequires that the urban infrastructure that
handles these issues be restructured. To that
end, it is increasingly important to develop technologies that protect urban functions
from harm during the process from structural
demolition to renewal, to prevent any adverse
effect on peripheral environments, to enable
space-saving and shorter-term demolition
and to skillfully control both time and space.

Demolition of High-rise Buildings andDismantling of Bridges
In light of this, this issue (No. 44) features anarticle on steel-structure demolition and subsequent rebuilding methods and introduces
practical examples of high-rise buildings andrailway/highway bridges that have been demolished and rebuilt.
First, the demolition of high-rise buildings is discussed. In Japan, high-rise buildings that were erected to make effective useof the narrow parcels of land available in urban centers are now entering a stage of needed renewal or reconstruction. In response,
safe and environmentally friendly demolition technologies have been developed thatare being put into practical use. While thedemolition of high-rise buildings is basically carried out by combining the use of reinforced-concrete and steel-structure demolition technologies, the actual technologies
used differ depending on building height andother structural conditions. Among the demolition methods introduced in this feature article are the block demolition method using
tower cranes, the cut and take down demolition method and the closed upper-floor de-molition method.
Next, methods for dismantling bridges,
typical social infrastructure, are discussed. In
bridge dismantling projects, diverse kinds ofrestrictions are imposed on the dismantlingof existing bridges, and the selection of an
appropriate demolition method requires careful consideration. The current feature article
introduces the various restrictive conditions
that must be hurdled in the dismantling ofrailway and highway bridges.
￭

Reverse construction demolition method

Cube cut demolition method

Simultaneous bridge dismantling method using
barge

Closed demolition method

Cut and take down demolition method

7 Steel Construction Today & Tomorrow April 2015

Upper-floor closure-type demolition
methodRebuilding of highway bridge

High-rise Building Demolition

Environmental Performance of Closed
Demolition Method for High-rise Buildings
by Hideki Ichihara, Taisei Corporation
Urban redevelopment projects are increasing
every year, and it is no longer unusual for therebuilt high-rise buildings to exceed 100-m
heights. With this growth, building demolition carried out in densely populated urban
areas is being called upon to implement proper countermeasures to mitigate the effects ofdemolition work such as noise and dust on
the surrounding environment. One effective
approach for achieving this mitigation is theclosed building demolition method.
In closed demolition work, a temporaryclosed space (like a cap) is erected on the topmost floor of the building that is to be demolished, and all activities from demolition to
the collection and disposal of the demolishedmembers take place within this closed space.

Conventional demolition methods have generated concerns about the spread of dust andthe propagation of noise in surrounding areas. The closed demolition method, however, can mitigate these concerns and greatly reduce the environmental burden imposed on
the surroundings. Further, the method is environmentally friendly and can successfully secure a favorable working environment within
the closed space.
Three Major Effects of Closed 		
Demolition Method
The first effect of this method is the suppression of noise propagated to the surroundingarea. This is achieved by constructing theclosed space using highly effective sound-

Table 1 Effect of Ventilation Amount on Environmental Factors
Environmental factor

Large ventilation amount(large ventilation opening)

Small ventilation amount(small ventilation opening)

Noise

Increase of demolition noisepropagated to the outside

Increase of internal soundpressure level due to theclosed space

Dust

Increase in the amount of
demolition-induced dust
scattered to the outside

Rise in the amount of internal
dust density due to insufficientventilation

Thermal condition

Colder working environment
due to strong (cold) wind in
winter season

Hotter working environment
due to shortage of heat
discharge in summer season

Fig. 1 Examination of Size of Ventilation Opening in Closed Space Upper
Section by Simulation
Closeddemolition method
Position of section

Conventional
demolition methodDustdensityHigh

Prediction of
dust/sootscattering

Low
Relative
A-weighted
soundpressure level

damping members and materials. In two recent demolition projects, noise damping was
improved by 17~23 dB compared to conventional methods.
The second effect is the suppression ofdust that would otherwise be scattered to thesurrounding area. By enclosing the floorsthat are being demolished in the upper section of the building where strong winds blow,
it is possible to recover the dust that is produced by the demolition work. When themain building of the old Akasaka Prince Hotel was demolished, more than 80% of all
the dust generated was recovered within theclosed space.
A third effect is the improvement of the
hot and humid environment that is inherent inclosed-space demolition. By solar radiation
shading during the summer season, it is possible to reduce the wet-bulb globe temperature (WBGT) by 2°C compared to the outdoor temperature, thereby lessening the riskof heatstroke among workers.
Design of Ventilation System for
Closed Space
In order to mitigate the environmental effects
of demolition through use of the closed demolition method, it is important to design aventilation system for the closed space. As
shown in Table 1, improvements to the working thermal environment, enhancement of thenoise damping performance and reductionsin the amount of scattered dust are largely
governed by the size of the ventilation opening in the closed space. Furthermore, there
is a trade-off relation between these factors.
Therefore, it is most important to design anappropriate ventilation system by conducting simulations pertaining to dust generation,
thermal environment and noise propagation,
taking account of the season, the demolitionarea and the surrounding area (Table 1 andFig. 1).
￭

Prediction ofnoise
propagation

April 2015 Steel Construction Today & Tomorrow 8

High-rise Building Demolition

Cut and Take Down Demolition Methodby Shigeru Yoshikai, Ryo Mizutani and Hitoshi Uehara, Kajima Corporation
Outline of Method
In the cut and take down method, a core wallis installed to secure seismic resistance, thebottom of 1st-floor column is replaced withhydraulic jacks, after which the building isdemolished 1 floor at a time, starting at thelowest level and moving upwards in the following cycle:① Cutting of columns to 70 cm-long pieces byremoving the jack load (suspension cutting)② Supporting the columns by extending thejack (cutting all columns by repeating ①
and ②)③ Lowering the columns by means of simultaneous jacking down (lowering of each floor
by repeating ①, ② and③ by 5~6 times)④ Demolition of beams
and floors (Refer toFig. 1)
Demolition of theabove-mentioned
24-story building wascompleted at a pace of 3days/1 floor, or 3 months
in total.
Photo 1 Full view of demolition employing cut and take down method

Environmental considerations are importantduring building demolition, particularly inurban areas. The “Kajima cut and take down
method” developed by Kajima Corporation isa package approach composed of various environmentally-friendly technologies and thejacking-down method in which a building isdemolished starting from the lowest section,
as if removing the lowest piece in a stack ofbarrels.
This method was applied in the demolition of the Resona Maruha Building, a rigid-frame 24-story building having a height of
108 m and a total floor area of 75,413 m2.
(Photo 1)

Fig. 1 Demolition Cycle and Concept of Suspension Cutting
Axial force

Suspended
state

Concept for axial force transfer duringsuspension cutting

Fig. 3 Reduction of CO2 Emissions

Fig. 2 Core Wall and Load-transfer Frame

1000

Core wall

Load-transfer
frame

9 Steel Construction Today & Tomorrow April 2015

Environmental Considerations
The cut and take down method is a highly
eco-friendly method that efficiently suppresses CO2 emissions. The adoption of this method allows a 17.8% reduction of CO2 emissions compared to the conventional methodof demolishing a building from the top floor
down (Fig. 3). Among the factors contributing to this reduction are the use of larger-capacity heavy machinery and a reduction in
the number of machines required, made possible by the performance of repetitive demolition operations at the same position; the resulting improved demolition efficiency; andthe adoption of automatic gas cutters.
In addition, new devices and approaches
have been introduced-air flow prediction
analysis to prevent the scattering of dust andsoot, micro electrical charge mist (μEC) toabsorb dust and soot, noise propagation prediction analysis to suppress the propagationof noise and vibration, and an active noise
control device (ANC).
♦♦♦
Demolition of the above-mentioned 24-story high-rise building located in an urban area was successfully completed by making themost of the seismic-resistant and eco-friendly cut and take down method.
￭

CO2 emissions (t-CO2)

Replacement ①Suspension ②Jacking ③Jackingof 1st-ﬂoor
cuttingup
down
column with jack

Jack

Securement of Seismic Resistanceduring Demolition
In demolition work using the cut and takedown method, the columns are in condition of
disconnection. In order to secure seismic resistance capable of withstanding a great earthquake during demolition, RC core walls witha height of about 13 m from the 1st-story floor
and steel-structure load-transfer frames weredevised and installed at 4 locations (Fig. 2).

Reduction by
17.8%

Electricity

5000FusioncuttingHeavymachineryfuel
Conventional Cut and takedown method
methodHigh-rise Building Demolition

Upper-floor Closure-type Demolition Method
by Masashi Morita, Takenaka Corporation
In the Takenaka Hat Down® method (enclosed upper-floor demolition method) developed by Takenaka Corporation, a building
is demolished floor-by-floor as the movabledemolition plant (hat) that encloses the top of
the building is lowered (Photo 1).
Outline of Method
This method does not apply a conventional
crusher; instead, it cuts the building into unit
blocks with cutters and wire saws installedin the hat, thereby producing almost no soot,dust, or noise.
Further the hat is equipped with a retractable roof and overhead traveling cranes (witha power generation function for lowering
cargo), which are used to lower demolishedbuilding blocks inside the building. As a result, there is no fear of flying or falling debris impacting the surrounding area, which,

Assembly of hat

accordingly, makes the method effective forbuilding demolition work in urban areas.
In addition, because the hat mechanism
is supported by peripheral columns, in contrast to conventional methods, the Hat Down
method does not require that a building structure be reinforced for demolition, and, further, this method can accommodate any structural configuration without reinforcement.
Application in the Demolition of aHigh-rise Building
The Hat Down method was adopted in the
demolition of the former Hotel Plaza (88 m
above-ground height) in February 2012. The
main specifications of the hat were: 19 m inheight, 19.6 m in width, 92.3 m in length, and
412 tons in gross weight (Photo 2); and, thehat was equipped with 3 overhead travelingcranes, each with a maximum suspension ca-

Demolition of high-rise floor

pacity of 7.5 tons. Further, the entire periphery of the hat was covered with sound-insulating panels and the ceiling of the hat wasa retractable roofing membrane that was deployed according to the type of demolition
work and in response to the weather, temperature and humidity conditions. (Photo 3)
A total of 22 jacks were arranged to raise
and lower the hat. After demolition of thefloor where the hat was located was complete, the entire hat structure was then lowered one floor, which would take about 1
hour.
The columns, walls and flooring of eachfloor were cut into 176 pieces, which werelowered through an opening provided inside
the building employing the 3 overhead traveling cranes. The demolition of each floor
was completed in 4 days.
￭

Demolition of medium-rise floor

Demolition of hat and low-rise floor

Photo 1 Demolition process using Hat Down demolition method
Movable demolition plant (hat)Retractable roof
Overhead traveling craneRaising/lowering equipment

Supporting frame
Photo 2 Full view of movable demolition plant (hat)Photo 3 Demolition equipment in hat
April 2015 Steel Construction Today & Tomorrow 10

High-rise Building Demolition

Cube Cut Demolition Methodby Yoshihito Mizushima, Obayashi Corporation
Outline of Method
The “Cube Cut” demolition method (quakeproof, quiet, quick and block-by-block demolition method) has been developed by
Obayashi Corporation. In this method, thebuilding structure (columns, beams andflooring) is cut into blocks, which are thenlowered to ground level where they are processed into smaller blocks and are separated(refer to Fig. 1 and Photo 1). Because crushers are not used on the top floor, pieces ofcrushed concrete are not scattered about andnoise, vibration and soot/dust are effectively
suppressed, making this an eco-friendly demolition method.
Further, this method can prevent building collapse during an earthquake. Seismic
safety during demolition is secured by providing the appropriate procedures for cutting
the structural frame and measures to prevent
building collapse.

Fig. 1 Cube Cut Method
Skyjuster• Safe maintainingof posture ofsuspended cargo

Automatic descending
scaffold• Securement of safety ofhigh-place work

Demolition ofinterior member,removal ofasbestos

Large-capacity cargo lift
• Improved efﬁciency incarrying-out of materialHigh cut method• Blasting of dry ice pellet to completely remove asbestos

High Application Versatility andShort-term Demolition
In the Cube Cut method, it is possible to selecta variety of elementary technologies, such as
tower cranes, large-capacity cargo lifts, automatic-descending scaffolds and protection
roofs, as the need arises. That is, it is a highly versatile demolition method that can meet
every user need (cost, environment, etc.) andevery demolition condition (structure, configuration, location, etc.). With a quick demolition rate of only 3 days/floor, this method has already been applied in the demolitionof 6 buildings, each adjacent to a functioning
hospital, hotel or office building (Photo 2).
In this method, the building structure isdemolished by means of a static work systemthat does not involve the hammering or dropping. Because of this, it is possible to demolish the interior equipment and piping, to cut
the floor slabs in advance, and to move thetimbering for the demolished blocks on lower floors while, at the same time, continuingdemolition work on the upper floor. This allows each process to proceed simultaneously,
thereby reducing the total demolition term.
This method is cost-competitive, safe andrapid and can be applied in the demolition of
not only high-rise buildings above 100 m but
also those over 60 m in height.
￭

Cube Cut method
Q: Quakeproof, quiet, quick
B: Block• Demolition of 1 ﬂoor in 5 days
• Sharp reduction in occurrence ofvibration, noise, soot and dust

Basic system
Dry ice pellet
Photo 1 Removal of columns and beams

Dry ice blasting Vacuum
Wet sand blasting suction
Ventilating
equipment

VacuumAeration cleaner
treatment

Sand blasting lead gun
Dry ice conveyor

Sand or dry ice

Ventilating equipment

Dry iceVacuum Sand
cleaner blasting conveyor
lead gun11 Steel Construction Today & Tomorrow April 2015

Photo 2 Demolition using Cube Cut method

High-rise Building Demolition

Reverse Construction Demolition Method
by Nobuhiro Okuyama, Shimizu Corporation
The “SHIMIZU Reverse Construction Demolition Method,” developed by Shimizu
Corporation, is an approach that can greatly mitigate the environmental effect of demolition work of high-rise steel structurebuildings. It allows highly reliable, economical demolition work that capitalizes on tower cranes and other general-purpose machinery (Photo 1)
Outline of Demolition Process
In the SHIMIZU Reverse Construction Demolition Method, crushing and breaking ofstructural members are done without conventional crushers, and on every floor, not only are the columns, girders and other steelframe members gas-cut, but the floor slabs
are cut using road cutters (Photos 2 and 3). In
block demolition employing this method, thestructural members are quietly cut while generating less dust and debris.
Then, in contrast to conventional demolition methods, the recovery of demolishedmembers does not involve the free-fall dropping of demolished members, but instead uses tower cranes to quietly lower them without vibration.
Meanwhile, the conventional fully assembled scaffolding system adopted as theperipheral protection method in high-risebuilding demolition is considered difficult toapply because of its need for vast amounts ofmachinery and materials and because of its
structural strength issue inherent in the use.
Accordingly, the reverse construction demolition method uses a movable-type peripheral

protection unit scaffolding system. This peripheral unit scaffolding is moved down foruse for the lower floor employing the tower
crane after finishing of demolition at respective floor (Photos 4 and 5).
In the planning stage of the current demolition method, a three-dimensional image
was prepared based on the design drawing toconfirm the demolition procedure and othertasks involved in demolition and to promote
the demolition plan (Fig. 1).
General-purpose Demolition Method
In the practical application of the reverse
construction demolition method, the noiselevel is reduced by about 20% compared toconventional breaking and crushing methods, and not only are vibrations diminished
but also dust and debris generation is greatly reduced.
In addition, the use of a movable peripheral protection unit scaffolding system makes it
possible to conduct demolition work without

Photo 2 Cut and removal of concrete-filled steel
tube column

people in the surrounding area being awareof a project’s progress.
In the method, because tower cranes andother general-purpose machinery are applied
as the temporary machinery, no restrictions
are imposed on the structural type or configuration of the building subjected to demolition. As an economical and general-purpose
demolition method, the reverse construction
method allows for versatile demolition plans
to be worked out.
￭

Photo 4 Moving down of peripheral protection
unit scaffolding for use for lower floor(moving down of 2 units in a lump)

Photo 5 A piece of movable peripheral protection unit scaffolding system (assembly
into 2 units in a lump)

Fig. 1 Verification of Demolition Process Employing 3-dimensional
Image (removal of slab)

Photo 1 SHIMIZU Reverse Construction Demolition Method underway

Photo 3 Cutting of slab
April 2015 Steel Construction Today & Tomorrow 12

Bridge Dismantling

Dismantling Methods for Steel Bridges
by Junichi Ikoshi, Yokogawa Construction Co., Ltd.
In steel bridge dismantlement, the imposition of various environment-related restrictions makes it impossible to simply reverse
the original bridge erection process. Accordingly it is necessary in advance to work out adetailed plan that will satisfy a diverse rangeof conditions and requirements.
In general, the selection of an applicabledismantling method will take into accountthe structural characteristics of the bridge andthe surrounding topographical conditions.
Also, the selection process will include a detailed examination of the applicable on-site
conditions related to the work yard and theheavy machinery to be used and with regard
to restrictions and various other requirements
such as keeping traffic capacity and minimizing the dismantling term. Then, conforming
to these conditions and requirements, a specific dismantling method is selected that optimally combines the various dismantlingequipment such as cranes, transporting systems (winches, jacks, carriages) and the temporary supporting members (bents, installation girders).
Fig. 1 shows the procedure for selecting
the dismantling method. For example, in cases when bents can be installed in the space
under the bridge and the yard for crane installation and block dismantling can be secured,
the bent method using truck cranes is adopted(Photo 1). Or, in cases calling for the avoidance of dismantling work in the location of
the existing bridge, a method to simultaneously dismantle the whole bridge structures
is adopted that uses cranes and transporting
systems that conform to the surrounding topographical conditions (Photos 2 and 3).
In bridge replacement in particular, numerous requirements will arise-the short-Fig. 1 Example of Selection of Bridge Dismantling Method
I Extraction
based onselection
factor(bridgecondition)

Structural condition• Mountain or urban area

• Structural type

• River, offshore, ravine• Span• Clearance, surrounding
environment etc.

• Curvature etc.

Applicable method(Filtering)

II Filtering
based ondetailed
condition

III Filtering
based onrestricting
condition

IV Engineering
decision• Crane, other equipment

Level to satisfy required condition 94%• Carrying-in/out route

Level to satisfy required condition 84%• Work yard etc.

Level to satisfy required condition 90%• Effect on adjacent trafﬁc

Good• Dismantling term and timeNG

• Replacement etc.

Acceptable

Recommended method (selection)

term replacement of an old bridge with a new
bridge, the avoidance of traffic closures, andthe restriction of work schedules to specified
times such as nighttime. To this end, the key
factor in the selection of a rebuilding method or plan is how to ensure safety, work efficiency, economic advantage and other inseparable issues and how to mitigate the effect of
the rebuilding work on the surrounding envi-

Photo 1 Bent method using truck crane (block dismantling)
13 Steel Construction Today & Tomorrow April 2015

Topographical condition

Photo 2 Simultaneous dismantling method forwhole bridge structures using crane

No measure forrestricting
condition

Determination of detaildismantling procedureand control method, etc.

ronment and existing traffic.
These design, planning and dismantling/rebuilding technologies are where the engineers working in these fields can show theirskills. These technologies are expected to be
widely adopted in dismantling/rebuilding
projects both in Japan and abroad.
￭

Photo 3 Simultaneous dismantling method forwhole bridge structures using barge

Replacement of Railway Bridge

Replacement of Railway Bridges inVietnamby Masao Minagawa, Yokogawa Construction Co., Ltd.
The Hanoi-Ho Chi Minh Railway Line (approximately 1,700 km in total length) has
been deteriorating due to damage during theVietnam War and to superannuation. In orderto improve the safety of the bridges on theline, the project has been planned that promotes the improvement of 44 of the damaged
railway bridges spanning rivers. The main
aim of the project is to secure railway service safety, to enhance transport efficiency
and to promote distribution services between
the northern and southern areas of Vietnam,
thereby contributing to the sustainable development of the national economy.
Between 2003 and 2007 improvements
were completed on 19 bridges with Official
Development Assistance (ODA) from Japan.
This led to a considerable reduction of travel time from the conventional 36 hours to 29
hours between Hanoi and Ho Chi Minh City.
The remaining ODA railway improvement
projects are currently underway and will result in improvements to all 44 bridges, further cutting the travel time to 24 hours.
The railway line is operated by means of asingle track system. Of the bridges subjected
to replacement, about 90% will be improvedby the “replacement during window time”
method in which the old bridge is replacedwith a new bridge while railway operations are temporarily suspended for several hours. The remaining 10%of bridges are to be newly installed at the moved railway
line in order to ease the railway curvature.
I was involved in the Construction Package No. 2 (CP2)and the Construction Package
No. 1-D (CP1D).
The works on the No. 20
Truoi Bridge (CP2) locatedin the central part of Vietnam(Fig. 1) are introduced in thisPhoto 1 Yard assembly of new bridge at No. 20 Truoi Bridge site

Fig. 2 Replacement Steps Taken for No. 20 Truoi Bridge
National Road No.1

BeforeTemporarily closed

Existing bridge

New bridge
Transfer of existing bridge（17 m）

National Road No.1

Temporarily closed
Transfer

New bridge

Fig. 1 Location of Replacement Project

Launching of new bridge（150 m）

National Road No.1

Temporarily closed
LaunchingTransfer of new bridge（9 m）

No.20
Truoi Bridge

National Road No.1

Transfer

After

National Road No.1

April 2015 Steel Construction Today & Tomorrow 14

article, which had been regarded as the mostdifficult in the 44 bridge improvement projects. The works include the replacement of 2
continuous curved chord Warren trusses with
3 continuous Warren trusses.
Replacement of the No. 20 Truoi
Bridge during Window TimeIn the conventional replacement during window time, the new bridge is assembled in advance at yard adjacent to the existing bridgeon which the train runs, and on the day whenrailway operations are suspended, the existing bridge is moved laterally to the opposite
side of the yard and the new bridge is laterally transferred to the vacant space and fixed.
However, in the No. 20 Truoi Bridge replacement project, because a bridge on thenational highway is located only 4 m away on
the downstream side from the bridge, the normal lateral transfer method could not be applied. As a result of studies, a method was adopted by which the new bridge was assembled

in advance behind the existing bridge (Photo1); then, on the day of replacement, a complex method was implemented combining theuse of lateral and longitudinal transfers: lateral transfer of existing bridge→longitudinaltransfer of new bridge→lateral transfer of
new bridge (see Fig. 2 and Photos 2,3). The
replacement of the bridge was to be completed within 6 hours.
Lateral Transfer of Bridges
In recent bridge replacement projects in Japan, the mainstream device in lateral transfers is the lateral-transfer jack, which does
not allow significant deviation in moving andcan easily make precise adjustments. On theother hand, in Vietnam, because of frequent
power failures and difficulty of repairing hydraulic system, the combined use of mechanical systems that require no electricity was
adopted: TIRTANK (roller moving system)as the transfer device, manual winches on
the tension side and TIRFOR (manual endless winch) on the runningaway prevention side.
Further, direct fastened
tracks (ballast-less tracks)
were adopted for the No.
20 Truoi Bridge. So, timeis needed to fasten the rails
after a lateral transfer, andthus the rails were fastenedin advance. Further, allsimple truss bridges wereconnected at lower chords
to mitigate the load working on the direct rail fastening system during lateral transfer.
During lateral trans-

fer, because a difference in lateral tension
between each bridge pier and the abutmentof the new bridge may occur, control of thestrokes (transfer amount) of the entire bridge
structure became a key issue. In the project,
the lateral transfer of the abutment parts withless traction force was preceded. And as a result the entire bridge structure including therails tended to cause angles at the bridge pierparts. In such case, in order to mitigate the effect working on the rail-fastening device ina timely manner, the replacement work was
conducted correcting the direction of movement of the TIRTANK.
Lowering of New Bridge onto theBridge Piers
After lateral transfer of the new bridge, thenew bridge was lowered by a margin of themechanical height of the TIRTANK (about
150 mm) in order to secure the prescribedrail height. During lowering operation, how
to lower the new bridge onto the bridge piers
at a low speed and how to synchronize thefour support points became an important issue in order to mitigate the load working on
the direct rail fastening system (Photo 4).
Commonly in Japan, 4 interlocked electric
pumps are used. However, because of thepower supply situation stated earlier, a manual pump was arranged for each jack to implement the lowering operation.
On the day of replacement, all operations
went smoothly, and the replacement processof the No. 20 Truoi Bridge was successfully completed in 5 hours, 1 hour less than theplanned 6-hour work time.
￭

Photo 2 Lateral transfer of existing bridge at No. 20 Truoi Bridge site

Photo 3 Lateral transfer of new bridge at No. 20 Truoi Bridge

15 Steel Construction Today & Tomorrow April 2015

Photo 4 Direct rail fastening system for directly laid railway

Rebuilding of Highway Bridge

Girder Removal in Rebuilding of Highway
Bridge on Metropolitan Expressway
by Yasuhiro Kakinuma and Atsushi Fukui, IHI Infrastructure Systems Co., Ltd.
Due to the improvement of the Loop RoadNo. 2, one of the urban planning highway
projects of the Tokyo metropolitan government, the Yaesu Route of the Metropolitan
Expressway interferes with a section of the
Loop Road No. 2 that is planned as an underground tunnel. This requires that the sectionof the Yaesu Route that is causing the interference be rebuilt.
In the following, we primarily describe
the removal of an existing bridge girder on
the Yaesu Route that was ordered by Tokyo
Metropolitan Expressway Company Limited(refer to Figs. 1 and 2).
Outline and Features of Existing
Bridge Girder Removal• Removal of Concrete Slabs
The method selected for concrete slab removal took into account the resulting effecton vehicle traffic under the existing bridgeand surrounding areas. Specifically, both drytype wire saws and concrete cutters that do
not require cooling water were adopted, andthe concrete slabs were cut into blocks (2.1 m
× 3.8 m) and removed to avoid onsite crushing.
In order to cut off the main girder from theslab in the box girder (non-composite girder)
section, the low-noise, high-efficiency jackup method was adopted (Photo 1). In the caseof the plate girder (composite girder) section,
the slabs on the main girder flange were left,

and the slabs between the girders were suspended using a crane and then were cut off.

• Removal of Existing Bridge Girder

at Crossing
Diverse restrictions were imposed on the removal of the bridge girder installed at the
Shiosakibashi crossing-reduction in thenumber of traffic closures, a narrow work
space and a short 5-hour limit on traffic closures, safety concerns and the effect of thework on the surrounding area. To cope withthese conditions, the nighttime large-block
removal method using transporters (multiaxle trucks) was adopted to remove the center span section of a 3-span continuous box
girder (Fig. 3).
Two transporters, each with 8 axles, werealigned in a row, and lifters were installedon the transporters to lift the girder up anddown (Fig. 4, Photo 2). To prepare for the useof transporters, advance track simulations
were conducted to discover obstacles on theroute and to take appropriate measures for removed girder transfer, and the running route
was marked on the pavement.
When the center span section of the
3-span continuous box girder was first removed, the both side span became the simple
girder, where the positive bending moment
increased. As a result, the main girder stress

PC
steel
bar

Hydraulic jackRemoved slab

PCsteel barBox girder upper flange

Photo 1 Concrete slab removal by means ofjack-up method

Fig. 2 Outline of Rebuilding Project3-span continuous box girderFig. 1 Location of Rebuilding Project

Before rebuildingywa
ssof prete Exou an
u R olites op
Ya etr
M

.
i St
ash
imb
Sh

Inn
Me er Circtrop ulaolita r Ron E utexpr ofessway

Shinbashi Exit/Entrance

Shiosakibashi
Crossing

surpassed the allowable level. To cope with
this, removal of pavement, slabs and concrete
barrier curb preceded removal of the centerspan girder.
The center-span girder (weight: about 250
tons; length: 26 m) to be removed was temporarily supported in advance using a setting
beam, and while applying gas cutting, thegirder was joined using a temporary splice
plate. The temporary splice plate served asa safety measure for any possible fall of thesetting beam and for suppressing the rapid release of internal stress during gas cutting. Further, supposing the case in which
the removal of the bolt joined to the splice
plate might become difficult, a jack was installed on both the upper and lower flanges

Bridge rebuilding
sectionShiodome
TunnelSouthboundNorthbound

Shiodome undergroundparking lot

NorthboundSouthboundSimple plate girder
Shiodome Exit/Entrance

Planned section for tunnel of Loop Road No. 2
Removal8010 pierSimple steel
deck box girder

RemovalRemoval8008 pier8007 pierRigid-frame bridge (simple steel deck
Simple steel
box girder connected with steel piers)
deck plate girder

After rebuilding
Shinbashi Exit/Entrance

Shiodome Exit/Entrance

Shiodome JCT
Shiodome
Exit

Loop Road No. 2 of Tokyo
metropolitan government(under construction)

Shiodome
Entrance

Shiodome undergroundparking lot
Planned section for tunnel of Loop Road No. 2
Erection8010’ pier

Erection
8007’ pierApril 2015 Steel Construction Today & Tomorrow 16

Fig. 3 Girder Removal Method
Removal by use of
Large block removal
Removal large-capacity crane**by use of transporters*
order
④
③
①

Preceding constructionof new bridge foundation

Removal by use oflarge-capacity crane**②

Planned section for tunnel of
Loop Road No. 2 (separate work)*Removal of every main girder of 1 span**Removal of each main girder of 1 span

Fig. 4 Lifting Up and Down of Girder by Use of Transporter
Elevation (at the time of girder supporting)
25700

21700

Girder support frame

1486.0000

84.9999

Beam for girder support

1300.0001

1∅
05

∅150

9600
Hydraulic unit

8061.0687

3400

Lashing(axial direction)

1515

Power pack

6300

8055
Hydraulic lifter

Goldhofer

2800

Existing girder
before removal

Photo 2 Upper: Girder replacing condition
Lower: Girder removal and transport

8870

Existing girder
before removal

2000

2570

2000

5-axle truck

1600

15600

9583.53-axle truck

1600

Elevation (at the time of transport)
25700

2000

21700

2000

Existing girder
before removal

Existing girder
before removal

Photo 3 Full view after bridge rebuilding on Yaesu
Route151513001300
4200
2570

614.0000

1486.0000

1∅
05

∅150

Hydraulic lifter
Power packGoldhofer

1600
8055

9600
12800

6770

84.9999

Girder support frame

1600

9600

8045

Fig. 5 Temporary Supporting Equipment
Tension restraining

Setting beam

Cutting
positionSide
span

RemovalgirderRemoval girderat center-span side
Compression restraining
Side-span
girderCenter hole jack (100 tons) × 2
Horizontal jack (100 tons) × 2

17 Steel Construction Today & Tomorrow April 2015of the girder (Fig. 5). The nighttime removal work was completed within the specified
limit placed on traffic closures by capitalizing on advance simulations and the provisionof risk management countermeasures, and by
reliable removal procedures.
Successful and Rapid Rebuilding ofBridge Girders
After removal of the existing bridge girders,the partial rebuilding of the Yaesu Route wascompleted 3 months earlier than the original schedule, largely due to the adoption of alarge block erection method using transporters and to other new approaches applicable
to construction cranes and temporary equipment (Photo 3).
Countermeasures against the superannuation of urban infrastructure are a pressing
task. We will be glad if the rebuilding technologies introduced above might serve asa reference in future large-scale bridge renewal projects that are expected to grow innumber.
￭Messages from New President and Committee Chairman・JSSC Operations

Message from New JSSC President
Yozo Fujino, President, Japanese Societyof Steel Construction

I assumed the postof President of theJapanese Societyof Steel Construction (JSSC) in June
2014.
JSSC was established in 1965
as an interdisciplinary organization that
includes makers of steel and construction
materials, construction companies, fabricators, consulting companies and academia. JSSC celebrates its 50th anniversary in 2015.
My primary task is to guide the enhancement and expansion of JSSC’s international activities and, secondarily, to promote the transmission of Japan’s advanced
steel construction technologies with theaim of creating secure and reliable societies worldwide. A typical example of ourtasks is the active involvement in the establishment of common international stan-dards such as those of the International Organization for Standardization (ISO) inorder to promote the worldwide spread anddevelopment of steel construction from a
global perspective.
In May 2015, IABSE (International Association for Bridge and Structural Engineering) will hold IABSE Conference
Nara 2015 in Japan. As a member of the
JSSC secretariat responsible for the conference, I will extend active support andcooperation.
To these ends, I will make the utmost
effort to nurture young researchers and engineers regardless of national origin so as
to reinforce technological foundations related to steel construction.
Taking the occasion of JSSC’s 50th anniversary and capitalizing on the Society’s
many achievements, I am preparing myself to tackle these tasks one by one. Lastly, I would like to ask for your continuous
support and understanding of JSSC operations.

Profile1972: Graduated from Faculty of Engineering,
University of Tokyo
1976: Ph. D (Civil Engineering), University ofWaterloo
1990: Professor, School of Engineering, University of Tokyo
2014: Distinguished Professor, Institute of Advance Science, Yokohama National University; Professor Emeritus, University of Tokyo
Major Awards• Medal with Purple Ribbon, Cabinet Office,
Government of Japan• Scanlan Medal, American Society of Civil Engineers (ASCE)• T.Y. Lin Medal, International Conference on
Bridge Maintenance And Safety• Nishino Medal, East Asia-Pacific Conferenceof Structural Engineering and Construction• George Winter Award, ASCE

IABSE Conference Nara 2015
IABSE (International Association for Bridge
and Structural Engineering) will hold IABSE Conference Nara 2015 for three days
from May 13 to 15, 2015 in Nara, Japan. The
main theme of the conference is “Elegancein Structures.” This conference will target
elegant solutions and structures that demonstrate structural resistance to earthquakes
and wind-including modeling and analysis
methods for these structures, in addition toconventional structural forms.
A variety of events are planned for eachday of the conference: delivery of keynote
lectures, presentations of technical papers,
commercial exhibitions, technical visits andother activities.
Taking this opportunity, all companies
and organizations working in steel construction are cordially invited to participate in theconference.

• Exhibit application and expense

IABSE Conference Nara 2015

A workshop Elegance in Structures will beheld at the conference venue on May 12 afternoon. It is basically a design competition
for a pedestrian bridge in Nara: the workshop
includes lectures by prominent engineers, re-Access to IABSE website (URL: http://www.iabse.org/)

view of designs proposed by young engineers(35 years old or younger) and an award ceremony.

Major Events: Keynote Lectures• Mike Schlaich (Technische Universität Berlin,
Germany)• Ian Firth (Flint & Neill, COWI, UK)• Kaori Fujita (the University of Tokyo, Japan)• Joseph Tortorella (Robert Silman Associates,
USA)• Sun Limin (Tongji University, China)• Akio Kasuga (Sumitomo Mitsui Construction
Co., Ltd., Japan)• Masao Saito (Nihon University, Japan)• Ryoichi Kanno (Nippon Steel & Sumitomo Metal Corporation, Japan)• Woo-Jong Kim (DM Engineering Co., Ltd., Korea)
Young Engineers Program• Venue
Nara Prefectural New Public Hall: Noh Theater,
Conference Room, Reception Hall & Gallery
URL:http://www.shinkokaido.jp/welcome/April 2015 Steel Construction Today & Tomorrow 18

JSSC Symposium 2014 on Structural Steel Construction
JSSC Symposium 2014 on Structural Steel
Construction, sponsored by the Japanese Society of Steel Construction, was held on November 13 and 14, 2014 in Tokyo and served
as a useful venue for researchers including
graduate students, engineers of steelmakers
and steel users, JSSC members and others
working in steel construction.
A variety of events were held, centering
around the Academy Session where theses lectures were given by contributors to the JSSC
annual journal Steel Construction Engineer-ing and the Memorial Lecture Meeting where
the winners of JSSC commendations for outstanding achievement in 2014 made presentations (for the prize-winning works, refer topages 1~6). Also featured were lecture meetings and panel discussions that aimed to comprehensively and functionally link the activities of JSSC’s various committees-StainlessSteel Session: presentation titled “Outline ofDual-phase Stainless Steel and Corresponding
Applications;” Engineering Session: presentation titled “From the Age of Construction to

the Age of Utilization-Urban Renewal andSteel Structures;” and International Session:presentation titled “Tackling Globalization.”

Prize winners of JSSC commendations for outstanding achievements in 2014

Message from New Chairman of International Committee
Kuniei Nogami, Chairman, International
Committee (Professor, Tokyo Metropolitan
University)

I have assumed thepost of Chairmanof the International Committee of theJapanese Society of
Steel Construction(JSSC).
Starting with issue No. 26 of Steel Construction Today & Tomorrow, published in 2009, our International Committee has been responsible for theeditorial planning of one of the three issues
that are published annually. Since its inauguration, JSSC has conducted wide-ranging activities in the form of surveys, research andtechnological development aimed at promoting the spread of steel construction and at im-proving associated technologies, and at thesame time it has extended cooperation to related organizations overseas.
Following the merger of JSSC with theStainless Steel Building Association of Japan
in 2010, JSSC’s field of operation expanded
to include not only carbon steel but also highly corrosion-resistant stainless steel. Consequently, we intend to actively transmit information throughout the world that is related toa wider range of steel construction areas.
As was true in issue No. 41, the previous
special issue of the JSSC for which our committee was responsible, our current issue, No.
44, introduces the excellent works and theses that have received a JSSC prize of commendation for outstanding achievement in2014. In addition, this issue features “demolition methods for steel structures,” particularly a demolition method for high-rise build-ings and steel bridges. It also reports on the2013 JSSC Symposium on Structural Steel
Construction and other major operations.
The International Committee, while working on multi-faceted responses to the internationalization of steel construction specifications and standards, promotes exchanges oftechnical information and personnel between
Japan and overseas organizations. As one aspect of these operations, we are attemptingwith this issue to inform our readers of JSSC
operations, trends in steel construction, andthe technologies and technological developments relevant to the planning, design, andbuilding of steel structures in Japan.
If you wish to obtain more detailed information about the various articles contained inthis issue or to receive related technical information, please do not hesitate to contact the
JSSC secretariat (info-jssc@jssc.or.jp).

Request for Participation in Survey of Steel Construction Today & Tomorrow
The survey forms are available in two formats:• At the JISF Website→Enter “jisf” in the search window of your internet browser→Click on the tab for Steel Construction Today & Tomorrow

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→Click the survey form
• Printed Form for Faxing
A survey form is enclosed in the magazine sent to our regular subscriber.
After filling-in, please fax to +81-3-3667-0245.
© 2015 The Japan Iron and Steel Federation
Edited byCommittee on Overseas Market Promotion, The Japan Iron and Steel Federation
Chairman (Editor): Keiji AndoP 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.