development of new building codes in...

New Building Codes in IndiaDevelopment of

TODAY…– Status of Current Building Codes– Development of Earthquake Codes– Some New Initiatives…

3 Status of Current Building Codes

Building Codes in India

2,000National Building Code 2016

Infrequent RevisionsHarmonization of Seismic Codes initiated

Buildings

SetsPhysical Planning

DesignConcrete, Steel, Masonry, Aluminum

Soil‐Foundation SystemsMaterials

ConstructionServicesSafety

400Safety

10Earthquake

RURAL AreasSelf‐built

URBAN AreasContractor‐driven

Building StockRC ~ 11,000,000Clay Brick ~ 147,000,000Stone ~ 43,000,000Wood ~ 3,000,000Mud ~ 66,000,000Informal ~ 35,000,000

Total 305,000,000

• Engineers/Architects with knowledge of Earthquake Engineering ??

Census of India, 2011

Engineered ??

Non‐Engineered

320,000,000 2018

National Vision• ZERO Tolerance to avoidable deaths

Earthquake Resistant Buildings

Estimate Hazard & Analyse Structure

Design and Detail

Assess and Retrofit

Standards

New Structures

Existing Structures

IS 1893

IS 13920

IS 15988

Earthquake Safety Standards

Part Title Indian StandardIS 1893 IS 13920 IS 15988

Code of Practice Code of Practice GuidelinesCriteria for Earthquake Resistant Design of Structures

Ductile Design and Detailing of Structures subjected toSeismic Effects

Assessment and Strengthening of Existing Structures subjected toSeismic Effects

1 General Provisions and Buildings

Section A: General Provisions

Section B: Buildings

(a) Reinforced Concrete Buildings

(b) Reinforced Masonry Buildings

(c) Confined Masonry Buildings !!

(c) Structural Steel Buildings !!

Harmonisation of Indian Standards related to Structures subjected to Seismic Effects






2 Liquid Retaining Tanks: Elevated & Ground Supported

3 Bridges and Retaining Walls

Section A: Bridges

Section B: Retaining Walls







4 Industrial Structures and Stack‐like Structures

Section A: Industrial Structures

Section B: Stack‐like Structures

5 Dams and EmbankmentsSection A: Dams

Section B: Embankments







6 Base‐Isolated Buildings !!

7 Energy Dissipation Devices 8 Non‐Structural Elements !!

9 PipelinesSection A: Buried !!

Section B: Over‐Ground !!







9 Coastal Structures10 High Tension Lines &

Towers


Other Earthquake Safety Standard

S.No. Title Number1 Methodology for Seismic Microzonation in India2 …

Rapid VISUAL Screening

Conceptual VISUAL Survey

Simplified QUANTITATIVE Assessment

Detailed QUANTITATIVE Assessment

1

2

3

4

Post‐Earthquake Occupancy

Relative Degree of Damage

Overall Safety Margin

Building & Component Deficiency

4 Levels of Assessment

4 Levels of Assessment

1

3

4Rigo

ur

Time

2

23 Development of Earthquake Codes

Earthquake

An earthquake is a sudden, rapid shaking of the Earth caused by sudden release of strain energy stored in rocks.

Earthquake Shaking• Induced Effects, not Applied Force

Equivalent Force on Building

roof

Fw

Ground Movement


Zero Mean :: Cyclic

Non-zero Mean :: Oscillatory

Time

Time

Minor (Frequent) Shaking

Moderate Shaking

Severe (Infrequent) Shaking

No structural damageNo non-structural damage

Some non‐structural damage

Structural damage, but NO collapse

Objectives of EQRD


– Damage expected in normal structures•Earthquake RESISTANT Structures

– NOT Earthquake PROOF Structures


0

Lateral L

oadH

Deformation

Earthquake Behaviour:: Inelastic

Wind Behaviour:: Elastic

H

4 Virtues for Earthquake Resistance

H

Strength

Stiffness

Lateral Deformation

Late

ral L

oad

H

Ductility

Configuration

4 Generations of Building Codes

H

Strength

Stiffness

Lateral Deformation

Late

ral L

oad

H

Ductility

Configuration1

2

2

2

4Energy

3

Stiffness

H

Stiffness

Lateral Deformation

Late

ral L

oad

H

1

• Concept of Defiance1

Earthquake Design

Stiffness-Based Design

Design for Ki only

Insufficient for Earthquake-Resistant Design

Strength‐Based Design

Design for Ki and VBd

Deformation‐Based Design

Design for Ki, VBd and max

Force Design1. No srtength heirarchy2. Design of members for shear

independent of P‐M interaction

Capacity Design1. Strong‐Column Weak‐beam 2. Design of members for shear dependent of P‐M interaction

Levels of EQRD 1 2 3Mandatory for Normal buildings

in low seismic zonesNormal buildings in moderate/high seismic zones

Critical and Lifeline buildings in all seismic zones

Optional for ‐ Normal buildings in low seismic zones

Normal buildings in moderate/high seismic zones

Energy‐Based Design

Design for Ki, VBd (??), max and E

1

Indian Standards forEarthquake Resistant Design started here in 1962

Strength• Concept of Force

2AH

Lateral Deformation

Late

ral L

oad

H

Strength

2Configuration

2

Strength• Estimation of Design Force corrected in 2016

– Design Criteria fully specified•5% damping, Sa/g, Ta, m and L, Methods: Analysis/Design

– R factors – Design Vertical Acceleration Coefficient Av

– Minimum VB

– Cracked Section Properties Ieff

2A

H

Strength• Level of Design Force incorrect still

– Earthquake Hazard not represented correctly through Seismic Zone Factor Z•4 Zones

– V o.36g– IV o.24g– III o.16g– II o.10g

2A

0.36 g 0.40 g

0.35 g 0.40 g

0.36 g??

0.32 g0.11 g

0.40 g0.36 g

0.30g

0.22 g

1.0 g

1.2 g

Peak Horizontal Ground Acceleration

WAWgS

IR

ZH h

aeMCED

WAW

gS

IR

ZH h

aeMCED

Strength• Level of Design Force incorrect still

– Design Acceleration Coefficient Ah

2ACountry PGA Z/ZIndia Ah Ah/Ah, India Ah/Z

Greece 0.36 1.00 0.26 2.88 0.72

Turkey 0.40 1.11 0.13 1.44 0.33

Iran 0.35 0.97 0.14 1.56 0.40

Pakistan 0.40 1.11 0.19 2.11 0.48

India 0.36 1.00 0.09 1.00 0.25

Nepal - - 0.09 1.00 -

Indonesia 0.30 0.83 0.19 2.11 0.63

Philippines 0.40 1.11 0.11 1.22 0.28

Australia 0.22 0.61 0.15 1.66 0.68

Japan 1.00 2.78 0.30 3.33 0.30

New Zealand 1.20 3.33 0.25 2.78 0.21

Configuration• Concept ofSeismic Structural Configuration– Convex Shapes

2A

Directions of earthquake shakingConvex Form

Concave Form

Directions of earthquake shaking

Configuration• Concept ofSeismic Structural Configuration– Convex Shapes

2A

Simple Shapes Complex Shapes

Configuration•No Torsional Mode in first 3 modes

– Along each principal plan direction

Z

Y

X

2A

• Poor earthquake performance…

Configuration•URM Infill Walls

– Diagonal Strut Action

2A

Cracks

Gap

Infill walls move together with columns under earthquake shaking

Configuration•URM Infill Walls

– Strut width

where

Lds

F

F

wds

ds40

hds L1750w ..

4

cf

mh hIE4

2tEh sin

2A

Configuration•Open Ground Storey Buildings

– But, parking must within the building footprint– Mandatory to provide RC walls in such buildings

230mm230mm

2A


– Horizontal Storey Shear Force

Floo

r Lev

el5

4

3

2

1

Increases downwards

along height

2A

Configuration 2A


– Storey Strength

~ 11 : 12

2A


– Storey Stiffness

~ 101 : 110

2A

0

20

40

60

80

100

120

140

160

180

0 1 2 3 4 5 6

Configuration• RC Structural Wall

– Effectiveness

Structural Plan Density (%)

Mo

men

t in

In

teri

or

Co

lum

n (k

Nm

)

Wall SPD = 2%

2A

Earthquake Design


Design for Ki only


Strength-Based Design




Force Design1. No strength hierarchy2. Design of members for shear

independent of P-M interaction

Capacity Design1. Strong‐Column Weak‐beam 2. Design of members for shear dependent of P‐M interaction








2A

53 Changes Underway

Ductility

H

Lateral Deformation

Late

ral L

oad

H

Ductility

y

y

max

max

• Concept of Ductility2B

Ductility

H

Strength

Lateral Deformation

Late

ral L

oad

H• Concept of Ductility INDIRECTLY

– Detailing

2B

2Configuration2

Ductility

2

Ductility• Design

– 2R = 10• IF = 2,R = 5

– Does the structure have a =5 (assuming it is a short period structure)?

• Verification2B

?H/Hp

0.050

0.5

1.0

0.10 0.15 0.20

1.5

/L

Ductility

(Feq)max

(Feq)max

M

V

V

M

Vc

Vc

Earthquake Design


Design for Ki only








Capacity Design1. Strong-Column Weak-beam 2. Design of members for shear

dependent of P-M interaction








2B

Deformability• Concept of Max. Lateral Deformation

3H

Lateral Deformation

Late

ral L

oad

H

Deformability

max

3

Deformability•Displacement Based Design

– How does it help?

3H

Lateral Deformation

Late

ral L

oad

H

cap maxmax

Deformability 3H

0

?

Late

ral L

oad

H

Lateral Deformation

Global Collapse Mechanism• Current Design Method

– Does NOT guarantee

Plastic Hinges

H (kN)

(mm)

125 250 375 500 625 7500

200

400

600

800

1,000

1,200

Elas

tic

Pla

stic

3

Global Collapse Mechanism•NOT predetermined

– ONLY Member Hierarchy addressed

GOOD Mechanism

POOR Mechanisms

3

Global Collapse Mechanism• Closed Loop Method of Design needed

0

H

0

H

3

Global Collapse Mechanism

Connection Rotation 0

Conn

ectio

n M

omen

t M/M

jy

Web Plates

Web Angles

Flange Angles

Flange Angles and Web Angles

Flush End Plates

Tee Stub

Extended End Plates

Top and Bottom Plates

Fully Welded

Flexible Flexible

Semi-RigidSemi-RigidRigidRigid

WeakWeak

Strong-axis ConnectionFlexibility

Relative Strength

3

Earthquake Design


Design for Ki only




Deformation-Based Design













3

Energy•Ground Motions

Dynamics of StructuresA.K.Chopra

4

Energy• Input by Earthquake to Structure

4

Duration of Earthquake Shaking

Input Energy

Ener

gy

Energy• Energy absorbed WITHOUT Hysteresis

4


Kinetic and Strain Energy

Ener

gy

Viscous Damping Energy

Energy• Energy absorbed WITH Hysteresis

4


Ener

gy

Hysteretic Energy

Viscous Damping Energy

Kinetic and Strain Energy

Energy• Energy absorbed during cyclic loading

4

Bad Good

Δ Δ

H H

Energy• Cyclic behaviour

– Stable Hysteretic Response

4

Joint Distortion 0

Joint Shear V/Vy V

V

Earthquake Design


Design for Ki only















Energy-Based Design


4

Seismic Design


Design for Ki only

INSUFFICIENT forEarthquake-Resistant Design


K i and VBd


K i, VBd and max

Force Design

(1) No hierarchy of relative strengths of members

(2) Design of members for shear independent of P-M interaction

Capacity Design

(1) Strong-Column Weak-Beam Philosophy

(2) Design of members for shear dependent of P-M interaction

Energy-Based Design

K i, VBd(??), max and E

Currently under

RESEARCHCollapse

MechanismDeformability

Energy Absorbed

Currently under

DEVELOPMENTCollapse Mechanism

Deformability

Currently IN PRACTICE

Levels of EQRD 1 2 3

Mandatory for Normal buildings in low seismic zones

Normal buildings inmoderate & high seismic zones

Critical and Lifeline buildings

Optional for - Normal buildings inlow seismic zones


4 Virtues for Earthquake Resistance

H

Strength

Stiffness

Lateral Deformation

Late

ral L

oad

H

Ductility

Configuration

7 Virtues of Eq. Resistant Structures

H

Strength

Stiffness

Lateral Deformation

Late

ral L

oad

H

Energy

Ductility

Configuration

Deformability

Desirable Collapse

Mechanism

1

2

34

6

5

7

78 Some New Initiatives…

The Road Ahead…•We can expect in upcoming revision of codes…– 1 step forward– 2 major changes– 3 new codes

The Road Ahead…• 1 Step Forward

– Generation 3 Earthquake Design•Displacement‐based Design

– Desirable collapse mechanism– Estimable deformation capacity

H

The Road Ahead…• 2 Major changes

– Earthquake ACCELERATION Zone Map•Probabilistic Seismic Hazard Assessment

Near‐Field Motions

S.T.G.Raghukanth

Finite Elemen

t Mod

eling

Eurasian PlateEurasian Plate

Indian PlateArabianSea

Indian Ocean

Bay ofBengal

The Road Ahead…• PSHA

– Potential events– Faults– Rock properties– Local soil properties

•YR = 5,000 years

PGA

S. T. G. Raghukanth

0.5g to 1.2g

The Road Ahead…• PSHA

– Potential events– Faults– Rock properties– Local soil properties

•YR = 10,000 years

PGA

0.7g to 1.5g

S. T. G. Raghukanth

The Road Ahead…• 2 Major changes

– Earthquake DISPLACEMENT Zone Map•First time attention drawn to Displacement

– Pipelines– High tension lines– Bridges– Tunnels

across faults

The Road Ahead…•Displacement Ground Motions

– Near‐Field Motions•Peak Ground Residual Displacement •Peak Ground Displacement

– Pulse Actions

The Road Ahead…•Near‐Field Motions

– Peak Ground Residual Displacement


– Peak Ground Residual Displacement

Disp

lacemen

t (cm

)

S.T.G. Raghukanth


– Peak Ground Displacement

Disp

lacemen

t (cm

)

S.T.G. Raghukanth

The Road Ahead…•Deformation Demand for each Seismic Zone

– Larger displacement demand underhigher intensity of earthquake shaking

SEVERE Shaking

MODERATE Shaking

0

H

MINOR Shaking

The Road Ahead…• 3 New Codes

– Ductile Steel Buildings– Base Isolated Buildings– Non‐Structural Elements in Buildings

In Closing …

Status

FORMPERFORMANCE

Today, focus is on…

But, what is needed is…

Performance‐Based Design •Quantify Performance

– Propose design clauses•Acceleration, Cracks, Residual Drift•Qualitative Expectations

– Immediate Occupancy, Life Safety, orCollapse Prevention

•Cost– Initial, Retrofit, or Life Cycle

RC Shear Wall

Foundation

Col

umn Beam

Slab

The Mission

Def. BD

National Disaster Management Authority, Government of IndiaBureau of Indian Standards

Professional Societies

2022

Earthquake Structural Safety Program Governments + Practitioners + Academics

2018 onwards

2025EBD

2018Duc. BD

2019

The Mission

Focus on 2 Aspects

Prevention

Mitigation

Preparedness

Response

Rehabilitation

Reconstruction

Evolve mechanisms to put in place

Systems & Processes

Earthquake Disaster Mitigation

Practice

5

4 3

1 2Typology Safety

Education

Policy

Earthquake Disaster Mitigation

Typology

Education

Safety

Practice

Policy

Typology Education Safety Practice Policy

Structural Safety Act

Risk Indexing

Peer Review

Licensing Engineers

ChangeBye Laws

Develop Standards

Undertake Retrofit

Continuing Education

Develop Skills

Full Scale Testing

New Technology

Outlaw U. Typologies

Technical Education

Manuals of G. Practice

Document Typologies

1

23 4

5

Knowledge Skills Attitude

The Critical Equation…

Competence = Attitude

+ Skills+ Knowledge

The Truth…•Many Teachers still consider EQ to be a force

– Strong capacity building campaign

•Nonlinear Analysis not taught in Colleges– Books and Teachers, before Curriculum

• Intuition missing of structural behaviour – Focus on hand‐calculations – Exaggerate deformation diagrams

The Truth…• Structural Safety is a pointed question

– Answers have to be precise•Lives are at stake

Constitution of IndiaArticle 3

Every citizen is responsible for the SAFETY of all other citizens also

Grateful • Professor Naveed Anwar

– AIT, Bangkok•Ms. Rakdao Pakdisi•Colleagues…

Clipart and Photos from InternetSome figures from

the Bureau of Indian Standards

Thank you…

Jai Hind!!

Thank you!!

[email protected]

development of new building codes in...

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