Reference １CONTENTS
 Outline of the Building Standards Law

Earthquake ResistanceStandards of Buildings

 Issue 1

Poor or negligent construction⇒Interim Inspection System
 Issue 2 Old buildings without sufficient earthquakeresistance⇒Promotion of seismic retrofitting Issue 3 Quality of architects⇒More stringent building confirmation⇒Revision of registered architect system(Focusing on Building Standards Law)

1

Earthquake Resistance Standards are Specified
by the Building Standards Law
Various standards are specified in the Building Standard Law,
including earthquake resistance standards of buildings
1 Standards in urban areas(1) Relationship between
building site and road(2) Purpose zoning(3) Building-to-land ratio(4) Floor area ratio(5) Building height2

Procedures in the Building Standards Law
Procedures from the development of a building plan to thestart of use are specified in the law and the involvement of
the administration ensures the safety.
Design(Architect)

2 Standards for buildings(1) Fire prevention/evacuation(2) Safety in daily life(3) Living environment/Sanitation(4) Structure (Earthquake
resistance standards)(5) Building equipment

Development ofa building plan

Start of construction
Construction(Constructioncompany)
Construction
supervision(Architect) ）Building official / Designated inspection and confirmation body

Application & receiving a
confirmation certificate

Construction

Application & receiving
a conformity certificate

Completion ofconstruction

Application & receiving
a conformity certificate

Building
confirmation

Examination ofStructural
calculation

Interim inspection

Final inspection

Start of use
3

Earthquake Resistance Standards

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Basic Concept of Earthquake ResistanceStandards - 2

Basic Concept of Earthquake ResistanceStandards - 1

Deal with it based on the risk management concept and considering
economic efficiency, rather than to build perfect buildings to resist
any possible earthquake

The basic concept is that the building structure must be safe
against not only earthquakes but also the dead load, live
load, snow load, and wind pressure.
Dead load:
Weight of concrete, reinforcing bars, etc.
Live load:
Weight of people, furniture, vehicles, etc.
Snow load:
Weight of snow
Wind pressure: Swaying caused by wind
Earthquake: Shaking caused by an earthquake(1) Regular dead load and live load shall be safely
supported.
(2) No damage shall be caused by a medium earthquake thatrarely occurs (once in 20 years).
(3) No fall or collapse shall be caused by a large earthquakethat very rarely occurs (once in 100 years)

5

6

Revision of the Law, with Earthquake as a Trigger
In Japan, a country of earthquakes, large scale earthquake disasters have trigged thestrengthening of earthquake resistance standards. The base of the current standards
were introduced in 1980.
Earthquake
The Tokachi-Oki Earthquake (1968)
Many cases of damage to RC buildings
M 7.9, 49 deaths, 673 buildings collapsed
The Miyagi-Oki Earthquake (1978)
Damage to the buildings with pilotis or large eccentricity
M 7.4, 27 deaths, 651 buildings collapsed
The Great Hanshin-Awaji Earthquake (1995)
Damage or collapse of the buildings with old earthquake
resistance standards or poorly constructed
M 7.2, 6,432 deaths, 104,906 buildings collapsed

Revision of the Law
Introduction of new earthquake resistancestandards (1980)
・ New provisions of two-step structural
calculation
・ Increase of the shear wall area for woodenbuildingsIntroduction of interim inspection (1998)(reference)
Introduction of the Law for Promotion ofSeismic Retrofitting of Buildings (1995)
7Earthquake Resistance Standards

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Earthquake Resistance Standards

91011123Reference １1314

Method of Structural Calculation introduced in 1980

Consideration of Story Deformation Angle
Floor withsignificant
deformation

Story deformation angle: Deformation of each floor
15

Earthquake Resistance Standards

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Method of Structural Calculation introduced in 1980

Consideration of Stiffness Ratio andEccentricity Ratio

Method of Structural Calculation introduced in 1980Retained Horizontal Strength≦Stiffness ratio: Balance ofeach floor’s stiffness

Eccentricity ratio: Balance ofeach floor’s stiffness inhorizontal plane

Required horizontal strength:
Horizontal strength required foreach floor in the event of a large
earthquake

Retained horizontal strength:
Horizontal force that each floor’s
columns, beams, and shear walls
can bear

17

Interim Inspection System - 1

Issue 1
Defects due to poor or negligent construction
cause buildings are not constructed in compliancewith the earthquake resistance standards＊Work in the natural environment, unlike the case ofindustrial products＊No buildings are the same
＊Many people involved

In the Great Hanshin-Awaji Earthquake, significant
damage occurred due to defects caused by poor ornegligent construction.

The Building Standards Law mandates an interim inspection
during the construction period and specifies that the local
government shall determine its details.
（Central government mandates an interim inspection to apartment
houses exceeding three stories)
19Earthquake Resistance Standards

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Interim Inspection System - 2
In response, Tokyo Metropolitan Government (TMG) sets
the most stringent standards in Japan.
◆ Buildings subject to the interim inspection＊ All buildings with three stories or more, regardless of the structure
type◆ Target of the interim inspection＊ Wooden buildings: Roof construction＊ Steel or steel reinforced concrete buildings: Frames of the first floor＊ Reinforced concrete buildings: Floor construction of the second floor※ Buildings with a total floor area exceeding 10,000 m2: Foundation isrequired

Earthquake Resistance Standards

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Current Status of Earthquake Resistant
Residential Buildings

Issue 2
There still remain many buildings that do not meet thecurrent earthquake resistance standards＊ Earthquake resistance standards are becoming

There still remain many residential buildings in the Tokyo Metropolisthat do not meet the new earthquake resistance standards.
Earthquake resistantWooden detachedhouses
1.56 M houses

increasingly stringent in light of earthquake damage,changes in the social economy and the spread of newtechnologies.

Non-earthquake resistant

36%

64%
1.00 M houses

Apartment
Buildings
3.84 M buildings
25

Establishment of the Law for Promotion ofSeismic Retrofitting of Buildings

0.56 M houses

81%

19%

3.10 M. buildings
0%

20%

40%

60%

0.74 M buildings
80%

100%

26

Outline of the Law for Promotion of Seismic
Retrofitting of Buildings

 At the Great Hanshin-Awaji Earthquake, many buildings

 The owner of buildings used by general public

built before 1980 suffered severe damage
 Strengthening seismic resistance performance ofbuildings nonconforming current standards are thecritical issue

shall endeavor to consult seismic diagnosis
and retrofitting Approved seismic retrofitting shall not
influence any disqualification other thanseismic resistant requirement
 Local governments shall establish Seismic
Retrofitting Promotion Plan In October 1995, Enacted the Law for Promotion ofSeismic Retrofitting of Buildings
27

Earthquake Resistance Standards

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Structural Calculation Sheet Forgery Case

Issue 3

Mr. Aneha, a first-class architect, forged structural
calculation sheets to cut costs and reduce
construction time

There are architects who falsify the structural
calculation so that the earthquake resistancestandards are not met＊Deterioration of the trust in architects holding a nationallicense＊Lack of professional ethics as an engineer

29◆ 99 cases of forgeries were found nationwide◆ Cause large damages to the residents of the falsified
apartment buildings◆ The development of structural calculation sheets issophisticated and complicatedUtilization of computers Æ Difficulty in detecting aforgery

30

Revision of the Building Standard Law
Enforced in June 2007

Buildings requiring “Examination of Structural
Calculation”

1 More stringent building confirmation and inspection◆ Buildings of a certain height or higher → Examination of structural
calculation

Buildings scale

Structural
Calculation (S.C.)

1. Superhigh-rise
H > 60m

HighlysophisticatedmethodBuilding official / Designated inspection and confirmation body

Design(Architect)

Development ofa building plan
Examination ofApplication & receiving Building confirmationstructural calculation
Start of construction a confirmation certificate
Construction(Constructioncompany)
Construction
supervision(Designer)

Construction

Completion ofconstruction

Application & receiving
a conformity certificate
Application & receiving aconformity certificate

Start of use

Earthquake Resistance Standards

2. Large scale
RC, SRC H>20m
S
F >= 4-story

SophistcatedmethodInterim inspection

Final inspection

Judge if the structural calculation isconducted by the way specified in thelaw or with the approved computer
program in proper manner 31

3. Medium scale
F >= 2-storyor A > 200 m2

In case approved computer(Except W)

used to calculate allowable

4 Small scale

MLIT
approval
Validityof S.C.
arechecked

Building
Building
Certification
Confirmation

program by MLIT are notstressS.C. arenot required328

Reference １

Number of Application for Building Confirmation(Except PlanChange)
Numberof Application for Building Confirmation

Revision of the Building Standard Law
Enforced on June 2007

(Except Plan Change)

2 Penalty strengthened in relation to the work ofarchitects, etc.

Nomber of Applicatio

3000

1-3, Large & medium

2500

Details of violation

４, Small

2000

Violation of significant
substantive provisions, suchas the earthquake resistancestandards

1500
1000
500
0
Apr.

Jul.

Oct.

Jan. Apr.

2007

Jul.

2008

Oct.

Jan.

Apr.

Jul.

2009
33

Beforerevision
Fine of¥500,000

Revised3 years imprisonment /fine of ¥3 million (¥100
million for a corporation)

3 Disclosure of information on architects and architect
offices◆ Public disclosure of the names of architects andarchitect offices punished, etc.

34

Revision of Registered Architect System 《To ensure the necessary quality and capability 》

Registered First-class Architect
Periodic training (1 day every 3 years), Contents (law revision, construction
technology), Completion examination (true-false test)

5 years or more design experiencein structure / equipment design⑥ Training for first-class architects ofstructure / equipment design:
Lecture （3 – 4 days） and completion
examination (in description style)

3 years or more design
experience

Thank you for your kind attention⑧ Training for managing architects:
Lecture （3 – 4 days） and completion
exam (true-false test)⑦ Training for first-class architects ofstructure / equipment design:
Lecture （1 day every 3 years） and completion
exam (true-false test)

The involvement of registered first-class architects is required for the structure /35
equipment design of large scale buildings from May 2009

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369