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Masayoshi Nakashima
Professor, Disaster Prevention Research Institute, Kyoto University
President, Architectural Institute of JapanExecutive Vice-President, International Association
for Earthquake Engineering
Japan’s Way for Technological Developments in Building Design and Construction
What is Masayoshi Nakashima He is Professor at Disaster Prevention Research Institute
(DPRI), Kyoto Univ. He was founding Director of E-Defense, National Research
Institute for Earth Science and Disaster Prevention (NIED), from 2004 to 2011.
He is President of Architectural Institute of Japan (AIJ) since 2015.
He is Executive Vice-President of International Association for Earthquake Engineering (IAEE).
He serves as Editor of Earthquake Engineering and Structural Dynamics (EESD) published by Wiley.
He is Foreign Member of National Academy of Engineering and Member of Engineering Academy of Japan.
Japanese Culture to Building Construction
• Life attached to “wood”• Love to “detailing”• Love to “handcraft and manufacturing”• Exercise for “collaboration between design and
construction/manufacturing”
Today’s Topics
Japan’s Attitude to Technology Developments
• Tendency of Positivism• Emphasis on Verification in reference to “Actual
Behavior/Performance”
Background (1)
Japan is Green, featured with “Wood Culture”.Traditional use of line (1D) elements (rather than plane (2D) elements)Popularity of steel as extension of wood
Japan loves “detailing”, which characterizes Japanese architecture.Complicated roofing details, exquisitely crafted eaves, complex connections using interlocking, etc.Similar appreciation to modern buildings
Background (2)
Japan loves handcraft and manufacturing.Relatively high public status for “manufacturers”Love to new invention and sophisticated engineeringExcessive “technology-driven” attitude, leading to Galapogisization.
Japan exercises positive collaboration between design and construction (manufacturing)Equal partnership between design and constructionQuality assurance by disciplined construction
Topic I
Japan is Green, featured with “Wood Culture”.
○ Traditional use of line (1D) elements (rather than plane (2D) elements)
○ Popularity of steel as extension of wood
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A country blessed with mountains and wood
Areas Covered by Green
Wood – traditional material for constructions
Example Wooden Houses
1960 1970
100
50
(million m2)
43%33%
20%
3%
Annual Building Construction in Japan
1980 1990 2000 2009Year of Construction
Yes, steel is very popular in Japanese Construction.
Resemblance between Wood and Steel
Framing slender members
Rigid connections between beams and columns
Application to Large Structures by Wood & Steel
Todaiji Temple, World Largest Wooden
Building
Nagoya Dome,Made of steel trusses
Application to Towers by Wood & Steel
Toji Pagoda,Tallest Wooden
Tower
Eifle Tower TokyoTower
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Japan and SteelJapan is destined to use and love steel by culture.
Steel is characterized by “fast construction (preparation done in factory)”, “quality control (fabricated in factory)”, and“versatile applications (from small, large, tall, strange….)
Topic II
Japan loves “detailing”, which characterizesJapanese architecture.
○ Complicated roofing details, exquisitely crafted eaves, complex connections using interlocking, etc.
○ Similar appreciations to modern buildings
Topic II
We inherited many of those masterpieces built in the past
fifteen centuries
Connection made of exquisite interlocking
大虹梁
上段繋虹梁
下段繋虹梁
身舎柱 側柱
側柱上組物
身舎柱上組物
通肘木
方斗巻斗
巻斗
ダボ
枠肘木
大斗
ダボ鉄板
柱(一部)
枠肘木
通肘木
Connection made of exquisite interlockingなかぞなえ(中備)
蟇股かえるまた 長保寺多宝塔
詰組つめぐみ 円覚寺舎利殿
くみもの(組物)
出組でぐみ 平等院鳳凰堂 二手先ふたてさき 室生寺金堂
三手先みてさき 室生寺五重塔
三手目おだるき
尾垂木
一手目の肘木
二手目の肘木堂内では梁
一手目
ニ手目
三手目
一手目
ニ手目
三手目
組物の構造
Application to Modern Buildings
City Hall of Izumo City, Shimane
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Original Shrine
City Hall Steel Shearwalls City Hall Atrium
Topic III
Japan loves Handcraft and Manufacturing.
○ Relatively high public status for “manufacturers”
○ Love to new invention and sophisticated engineering
○ Excessive “technology-driven” attitude, leading to Galapogisization.
Respect to Craftsmanship
Armor
Sword
Mask
Umbrella
Fan
Bamboo ware
Pottery
Doll
clothes
Ceramic
Iron
LacquerWood Carving
Respect to Craftsmanship (continued)Japanese is “clever with hands/Fingers”.
Knitting
SwordsmithWeaving
Bamboo Work
Innovation of Steel Construction in Japan
Material-Oriented Development* High-Performance Steel* Ultra High-Strength Steel* Fire-Resisting Steel* High Toughness Steel* Ultra High-Strength Bolts* Low-Yield Steel* Energy-Friendly High-Strength Steel
Japan loves “innovation” via “manufacturing”.
Devise-Oriented Development* Buckling-Restrained Braces* Concrete Filled Steel Tubes (CFT)* etc.
High-Performance Steel
* Controlled Yield Strength* Controlled Ultimate Strength* Controlled Yield to Ultimate Strength Ratio* Adopted in JIS (Japan Industrial Standards)
– Introduction of “SN Steel Grade” –
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Fire-Resisting Steel
* Higher resistance against temperature* Less requirement for fire insulation
2/3 yield strength
Low-Yield Steel* Lower yield strength (100 MPa to 200 MPa)* Larger uniform strain* Larger strain hardening in cyclic loading* Used as damper material
low-yield steel
35
Low Carbon/Alloys High-Strength Steel
New ultra high strength steel
Environment-friendly
Resources saving
Reusable
CO2
Alloying elements
thermo-mechanical control process
Buckling Restrained Braces
Brace is good in providing both strength and stiffness if it does not buckle.
Short Brace(no buckling)
Long Brace Intermediate Brace
Low-yield–strength steel
Stiffeningsteel pipe
a
a
Low-yield–strength steel
Stiffeningsteel pipe
a-a section
Example of Buckling Restrained Braces Mechanisms of Buckling Restrained Braces
Restraining of buckling of brace wrapped by encasement
アンボンド材
モルタル
筋かい芯材
鋼管
Types of encasementExample of
Debonding Details
Mortar Steel Tube
DebondingmaterialSteel brace
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CFT
Concrete Filled Steel Tube (CFT)Familiarities to Composite Structures
– Use of SRC for decades
SRC (Steel Encased RC) Composite Slab
CFT
CFT – Construction
Push-in of Concrete
Topic IV
Japan exercises collaboration between design and construction (manufacturing)
○ Equal partnership between design and construction
○ Quality assurance by disciplined construction
Big Five Contractors
Obayashi(1.61*)
Kajima(1.52)
Shimiz(1.50)
Taisei(1.53)
Takenaka(1.02)
* Annual Sale in trillion yen
Active In-house R/D Institutions Design versus Construction
DesignArchitectureStructures
Environment
R/DStructures
EnvironmentAmenity
ConstructionJapanese Way:
• Positive Interaction among sectors• Culture of respect to manufacturing
Department of Architecture & Building Engineering
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Clean, Disciplined Construction (1)Management of Hundreds of Technicians of
Various Occupations
Morning Assembly Gymnastic Exercises
Instruction Session for Cranes Schedule Checking
Clean, Disciplined Construction (2)Efforts to Maintain Clean Construction Site
Cleaning Truck TiresSweeping
Keeping things tidy and in order Slogans
Clean, Disciplined Construction (3)Safety Control and Management
Covering Construction Site Lifelines
Daily Check of Safety Issues Attention to Level Difference
Design versus Construction
DesignR/D
Construction
Respect to Fundamentals
Values to Details
Life attached to “wood”Love to “detailing”Love to “handcraft and manufacturing”Exercise for “collaboration between design and construction/manufacturing”
Japan’s way for Technology Development
Japan’s attitude to technology developments
• Tendency of Positivism• Emphasis on Verification in reference to
“Actual Behavior/Performance”
Structural Damage in 1995 Kobe Earthquake
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Human/Property Loss by Kobe Earthquake
Building loss responsible for 70% of total damage cost
Building damage responsible for 95% of death toll
Standing Firm
3rd story failure
Wall damage- Acceptable -After
1981Before1981
Clear Contrast of Damage to RC Buildings
Earthquake engineering has a long history of “learning from actual earthquakes and earthquake damages.” That is, we first understand problems by actual damage; then develop engineering to patch them.
“Learning from Earthquakes”
1964 Niigata
Liquefaction
1968 Tokachi-oki
RC Shear Failure
1995 Kobe
Seismic Retrofit
It is a jumbo shaking table of 20 m by 15 m in plan, activated in 3D
Owned by National Research Institute for Earth Science and Disaster Prevention and open in 2005.
What is E-Defense?
Shaking Table and Actuator System Activities of E-DefenseSince 2005, E-Defense has completed forty some full-scale (or large-scale) tests for various structures.
Four-story Base-isolated Hospital
Pile Foundation Six-story Wooden HouseFour-story
Steel Frame
Six-story RC Frame
Two-Story Wooden House
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Test click here
Collapse Reproduction Applied to Wooden Houses(November 21 to 24, 2005)
Complete Collapse Test of Four-Story Steel Moment Frame
E-Defense Steel Collapse
Final Collapse
Local Buckling at Column Base
Local buckling at First Story Column Top
Final Collapse in First Story Blind Analysis Competition Participants from all over the world. Application through website. Competition for accurate simulation of collapse test Category :(1) 3D Analysis, Researcher (2) 3D Analysis, Practicing Engineer(3) 2D Analysis, Researcher (4) 2D Analysis, Practicing Engineer
Registration:115 teams(US:44, Japan:37, others:34) Final submission : 47 teams
(Japan:17, US:15, others:15) Please, predict my life!
Blind Analysis Competition – Examples (for JR Takatori 60%)
0%
100%
200%
300%
400%
500%
600%
700%
0 5 10 15 20 25 30 35 40 45Teams
( A
nal
ysis
/ M
easu
red
) ra
tio_
Analysis results of participants Measured
Statistics: Maximum drift angle of first story
(Y-direction)
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
0 5 10 15 20sec
Dri
ft a
ngle
of 1
st s
tory
Analysis(Y) Measured
A good example: Time history of first story drift
(Y-direction)
Calibration of Numerical Model: Beams
-0.1 -0.05 0 0.05 0.1-800
-600
-400
-200
0
200
400
600
800
Ke = 100000
My+ = 650
My- = -485
p+ = 0.030
p- = 0.015
pc+ = 0.250
pc- = 0.250
s = 1.0
c = 1.0
a = 1.0
k = 0.5
Mc/M
y+ = 1.20
Mc/M
y- = 1.05
k = 0.30
Chord Rotation (rad)
Mo
men
t (k
N-m
)
E-Defense-BeamC-MomentRotation
(Modified Ibarra-Krawinkler model,Lignos and Krawinkler 2009)
Composite Action
(Data from Pre-Test E-Defense Blind Competition: Composite
Beam under cyclic loading
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Calibration of Numerical Model: Columns(Modified Ibarra-Krawinkler model
Lignos and Krawinkler 2009)
-0.06 -0.03 0 0.03 0.06-500
0
500
Rotation [rad]
Mo
me
nt
[kN
-m]
Data from Pre-Test E-Defense Blind Competition:
HSS 300x300x9 tested in 45o
D
t
D/t=33
Mp
θp
Numerical Prediction of First Story Collapse Mechanism
0 1 2 3 4 5 6 7-0.05
0
0.05
0.1
0.15
0.2
Time [sec]
1st
Sto
ry D
rift A
ngle
[ra
d]
Experimental DataSimulation
Collapse Prediction: 1st story drift History
1st story collapsemechanism
2011 Tohoku Earthquake (March 11, 2011) Urban damage, such as observed in Sendai
Downtown Sendai Right After Qauke
Shear Failure of RC Columns
Collapse of First Story in Two-Story RC
Failure of House by Landslide Nonstructural Damage
Behavior of High-Rise in Sendai
• Difficulty in standing;• Partitions overturning;• Books thrown horizontal
and fell to floor with a parabolic orbit;
• No human injured;• Inhabitants evacuated
orderly using stairs;• Cars in ground parking
areas moved;• Those who watched the
building thought that it might break in the middle of the building;
• Seismograph in the building showed Shindo 7.
Constructed: 1998 (31 stories)Type of Structure: SRC, with passive mass dampers
Performance of hundreds of high-rises and base-isolated buildings in the Tokyo metropolitan area
600400
200
0
Tohoku Kanto Tokai Kansai
Num
ber 800
1,000
Aom
ori
IwIa
teM
iyag
iA
kita
Yam
agat
aF
ukus
him
aIb
arak
iTo
chig
iG
unm
aS
aita
ma
Chi
baTo
kyo
Kan
agaw
aS
hizu
oka
Aic
hi
Mie
Shi
gaK
yoto
Osa
kaH
yogo
Nar
a
Gifu
Wak
ayam
a
600
400
200
0
Num
ber
Tohoku Kanto Tokai Kansai
High-rises
Base-isolation
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An Example: Performance of high-rise building in the Tokyo metropolitan area
-60
-30
0
30
60
0 100 200 300 400 500 600 700
-150
-75
0
75
150
0 200 400 600 700
1.50.75
0
- 0.75
- 1.5
0.6
0.3
0
- 0.3
- 0.6500300100
Time elapsed (sec)
Dis
p. (
m)
Acc.
Dis
p.
(m/s
/s)
Roof Disp.First Story Acc.
Effect of Retrofit:
Disp. about 20% reductionAcc. about 30% reductionDecay after quake about 50% reduction
The figures and photos appearing in this slide are presented here by the courtesy of Taisei Co.
Recent Damaging Earthquakes in Japan
Recent Damaging Earthquakes in JapanYear Name Magni
tudeDeath
(missing)Injury Collapse Severe
1995 Hyogo-Ken Nanbu 7.3 6,437 43,792 105,000 144,000
1997 Kagoshima-Ken Hokuseibu 6.4 74 4 312000 Tottori-Ken Seibu 7.3 182 435 3,1012001 Geiyo 6.7 2 288 70 7742003 Miyagi-Ken Oki 7.1 174 2 212003 Miyagi-Ken Hokubu 6.4 677 1,276 3,8092003 Tokachi-Oki 8.0 1 849 116 3682004 Niigata-Ken Chuetsu 6.8 68 4,805 3,175 13,8102005 Fukuoka-Ken Seihou-Oki 7.0 1 1,204 144 3532005 Miyagi-Ken Oki 7.2 100 1 9842007 Noto-Hantou 6.9 1 356 686 1,7402007 Niigata-Ken Chuetsu-Oki 6.8 15 2,346 1,331 5,7092008 Iwate Miyagi Nairiku 7.2 17 426 30 1462008 Iwate Engan Hokubu 6.8 1 211 1 3792009 Suruga-Wan 6.5 1 319 62011 Tohoku-Chiho Taiheiyou-
Oki9.0 15,202
(9,761)5,338 97,932 51,466
Recent Damaging Earthquakes in Japan
Historical Records of Large Earthquakes
Huge Ocean-Ridge Quake - More to Expect in Near Future
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
2100
2000
Nankai Tonankai Tokai
1946 Showa 1944 Showa
1707 Hoei
1605 Keicho
1498 Meio
1361 Sohei
1096 Eicho
887 Ninna
684 Hakuho
1854 Ansei
Lessons from 2011 Tohoku• Nature is more formidable than what we want it to be. • What is assumed (expected, supposed, conceived) in
design, for example, design earthquake force, is determined by human (not by nature) in consideration of cost performance.
• No matter how less frequent it may be, a catastrophic disaster shall occur; in such a case, we cannot expect “no damage” any longer in our life and society.
Resistance
Deformation
Resilience
• After 2011 Tohoku, the term “Resiliency” is sensed more realistic. Here, I define “resilient” as ability to recover to its normal condition as quickly as possible. We need to develop technologies to promote prompt recovery.
Time
Performance
Very Short Time for Recovery
Now
Future
(1) Response to earthquakes beyond what is considered in structural design
(2) Continuing business and prompt recovery
Lessons to Earthquake Engineering Community
Specific Engineering Research Needed
(A) Quantification of collapse margin of high-rise buildings
(B) Monitoring and prompt condition assessment of buildings
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(1) Quantification of Collapse Margin: To make a consensus to the response to earthquakes that go beyond one considered by codes, we shall quantify the performance of each structure up to complete.
Engineering Research Need After 2011 Tohoku Earthquake –I–
No damage Collapse
1
23
4
Resistance
Deformation
Collapse MarginA delicate balance between safety and cost
Never ceasing urban society, characterized by “high performance”, “density”, and “globalization.
For continuation in life and business, “prompt response” immediately after the quake, i.e., “quick inspection” and “quick decision” is desperately needed.
Rapidly Grown Megacities
(2) Technologies for Enhanced Health Monitoring: To make our society more resilient, we need more advanced sensing and monitoring technologies by which we can detect damage and/or evaluate state of safety immediately.
Engineering Research Need After 2011 Tohoku Earthquake –II–
Wireless sensor
GPS
Liquefactionsensor
Earthquake Response
Structural damage
Damage to lifelines
Damage to piles
Shaking Table Test for Collapse of Steel High-Rise Building (Implemented in December 2013)
■ Shaking TableUse of E-Defense
■ SpecimenA height of 25 m adopted in light of E-Defense allowable limit (27 m)
■ Protection FrameDeveloped to protect collapsing specimen as well as to serve as a frame to lift specimen
■ Input MotionSynthesized motion considering simultaneous ruptures of three troughs
SpecimenProtection
Frame
Shaking Table
Construction of Collapse Specimen(November 15, 2013)
Synthesized Ground Motion
0 60 120 180 240 300 360 420 480-400
0
400想定長周期地震動
(Gal)
(s)Synthesized Acceleration History
・Amplification of Original HistoryAverage (110cm/s) baselineLarge (180cm/s) 1.64 timesVery Large I (220cm/s) 2 timesVery Large II (250cm/s) 2.27 timesVery Large III (300cm/s) 2.73 timesVery Large IV (340cm/s) 3.1 times (at the table capacity)
・Contracted to 1/√3 with respect to time domain
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Monitoring and Condition Assessment (Planned on December 2013)
Y1Y2
Y3X1
X2
X3
dc03 - 6F
Y1Y2
Y3 X1
X2X3
dc03 - 5F
Y1Y2
Y3X1
X2
X3
dc03 - 4F
Y1Y2
Y3 X1
X2X3
dc03 - 3F
Y1Y2
Y3 X1
X2X3
dc03 - 2F
0 2 4 6
0
5
10
15
Cumulative plastic deformation ratio
Flo
or
w/o damping
estimation(1)
estimation(2)
estimation(3)
レベル2損傷推定レベル1損傷推定
Level 1 Sensors• 25 servo-yype
zccelerometers• 200Hz Sampling
Level 1 System
Hei
ght =
25
m
Shaking Table Shaking Table
Level 2 System
SensorController
Level 2 Sensors• 152 MEMS
sensors(912 components)
• 500Hz Sampling
Collapse Test – December 11, 2013
Amplification of Original HistoryAverage (110cm/s) baselineLarge (180cm/s) 1.64 timesVery Large I (220cm/s) 2 timesVery Large II (250cm/s) 2.27 timesVery Large III (300cm/s) 2.73 timesVery Large IV (340cm/s) 3.1 times
(at the table capacity)Extreme I (380cm/s) 3.8 timesExtreme II (380cm/s) 3.8 timesExtreme III (380cm/s) 3.8 times
CollapseFinal Collapse OverviewFinal Collapse Connection
Collapse of lower stories, leaning to protection frame
Local buckling at column base
Fracture of beam end
Failure OverviewJapanese Culture to Building Construction• Life attached to “wood”• Love to “detailing”• Love to “handcraft and manufacturing”• Exercise for “collaboration between design and
construction/manufacturing”
Summary of Today’s Topics
Japan’s Attitude to Technology Developments• Tendency of Positivism• Emphasis on Verification in reference to “Actual Behavior/Performance”
High Quality Long Life Good Care
Detailing Modesty New Technology
What Japan wants to seek for good construction are: