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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: