Recent Experience in Turkey for Building Vulnerability and

Estimating Damage Losses

P. Gülkan and A. YakutMiddle East Technical University

Typical Residential Apartment Buildings in Turkey

Residential/Commercial Building under Construction

Street Scene, İzmit, Aug. 1999

DAMAGE IS ALWAYS ATTRIBUTABLE TO A COMBINATION OF ADVERSE CONDITIONS

Poor structural performance results from a mixture of:

• Inappropriate structural form

• Lack of design/detailing for earthquakeresistance

• Poor quality materials

• Inadequate foundation design

• Inadequate supervision of construction

• Non-enforcement of rational land-use policies

Code violations

0

0.1

0.2

0.30.4

0.5

0.6

0.70.8

0.9

1

Pro

port

ion

1 2 3 4 5 6 7

Damage Levels 1+2 Damage Levels 4+5

Number of Stories

DAMAGE RELATIONSHIP WITH HEIGHT: R/C BUILDINGS IN GÖLCÜK

5

31

100

-192

5

1926

-193

5

1936

-194

5

1946

-195

5

1956

-196

5

1966

-197

5

1976

-198

5

1986

-199

5

1996

-

020406080

120140160180200

Number of buildings

Year of construction

Damage Level

REINFORCED CONCRETE BUILDINGS IN GÖLCÜK

0102030405060708090

100

5

31

-192

5

1926

-193

5

1936

-194

5

1946

-195

5

1956

-196

5

1966

-197

5

1976

-198

5

1986

-199

5

1996

-

Number of buildings

Year of construction

Damage Level

R/C BUILDINGS UP TO THREE STORIES TALL

5

31

-192

5

1926

-193

5

1936

-194

5

1946

-195

5

1956

-196

5

1966

-197

5

1976

-198

5

1986

-199

5

1996

-

Number of buildings

Year of construction

Damage Level

010

20

30

40

50

60

70

80

90

R/C BUILDINGS TALLER THAN THREE STORIES

OVERCAPACITY GIRDERS BREAK COLUMNS

SOFT/WEAK GROUND STORIES

POOR ANCHORAGE OF REINFORCEMENT

COLUMN HINGING MECHANISM

COLUMN SHEAR FAILURE

CAPTIVE SHORT COLUMNS FAIL IN SHEAR

IMPROPERLY DETAILED JOINTS CAN DISINTEGRATE

NON-ENFORCEMENT OF HEIGHT ZONING MAY LEAD TO POUNDING BETWEEN BUILDINGS

Loss Estimation requires team-work among:

Geology

Seismology

Earthquake and structural engineering

Geotechnical engineering

Principal Components of Risk Analysis

Hazard Analysis

Modeling seismic sources

Soil type and geological factors

Attenuation modeling

Vulnerability Analysis

Assessment of the building stock Earthquake analysis

Develop vulnerability curves

Risk Analysis

Calculation of Probabilistic Risk Curves

Calc. materialCalc. material

losseslosses

HazardHazard

Event nucleation

Calculation of intensity

VulnerabilityVulnerability

Damage calculation

Building stockGeotechnical background

Principal Components of Earthquake Models

Hazard Assessment

Softer formation

Bedrock

Attenuation

Amplification

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0 5 10 15 20 25 30 35

Time, sec

Sa,

g

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0 5 10 15 20 25 30 35

Time, sec

Sa,

g

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0 5 10 15 20 25 30 35

Time, sec

Sa,

g

Modeling Seismic Sources

5.06.07.0

0

20

40

60

80

100

120

4 5 6 7 8

Siddet

Fre

ka

ns

Gutenberg-Richter

Attenuation Relations

Strike-Slip Faults

Joyner and Boore (1997)

Sadigh (1997)

Abrahamson and Silva (1997)

Ambraseys et al (1999)

Gülkan and Kalkan (2002)

Subduction Zone

Youngs (1997)

Gregor (1997)

Spudich et al. (1999)

Dependent on:

Earthq. Mag.

Rupture Mech.

Distance

Signal Prop.

Estimation of Ground Motions during Probable Earthquakes

0

20

40

60

80

100

120

4 5 6 7 8

Siddet

Fre

ka

ns

0

20

40

60

80

100

120

4 5 6 7 8

Siddet

Fre

ka

ns

0

20

40

60

80

100

120

4 5 6 7 8

Siddet

Fre

kan

s

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 1 2 3 4

Peryot (saniye)

Sp

ek

tra

l Iv

me

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 1 2 3 4

Peryot (saniye)

Sp

ek

tra

l Iv

me

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 1 2 3 4

Peryot (saniye)S

pe

ktr

al I

vm

e

Soil Type and Amplification

Sand and silt

Stiff clay

Rock

Stiff clay

Rock

Comparison of Vulnerability Analyses

ATC - 131985

Intensity is MMIExpert Opinion Curves

HAZUS1997

Spectral IntensityExpert Opinion Curves

Expert Opinion Vulnerability

Analytic Vulnerability

Judgment Based Hazard

Parameter

Empirical Hazard

Parameter

ACM2000

Spectral IntensityObjectively Developed Curves

Development of Damage Functions

Determination of typical structural types and their features based on design drawings

Analysis of earthquake response

Development of damage functions for each building type on basis of member damage

Determination of retrofit strategies and associated costs

Assembly of damage functions for each building type

Typical Structural Features

Structural characteristics Material type Plan area, story height, span widths, number of spans Number of stories

Design of Typical Buildings Design calculations Material properties Blueprint drawings

USA: Building Types

Steel Moment resisting Braced Frame

Reinforced concrete Moment resisting Shear wall

Precast concrete Frame Panel Tilt-Up

Timber

Reinf. Conc. Frame/Wall

Steel frame

Tilt-upReinf. Conc. frame

35 building types

Modeling and Analysis of Building

SAP 2000

Structural Engineering Is:

The Art of Using Materials

(with properties that can only be estimated)

To Build Real Structures

(that can only be approximately analyzed)

To Withstand Forces

(that are not accurately known)

So That Our Responsibility to Public Safety Is Satisfied!

Considering Uncertainties

E M Fy

1 2 10

Push-over Analysis

Element Level Damageability

D%

Intersection of capacity and typical demand spectra show ing the predefined damage states

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55

Spectral displacement (m)

Spe

ctra

l acc

eler

atio

n (g

)

Capacity Curve

Demand: 18.6%g

Demand: 29.3%g

Demand:33.2%g

Demand:35.2%g

Performance Point

Slight damage Moderate

damage

Complete damage

Extensive damage

ANALYTICAL ESTIMATION OF FRAGILITY

Capacity and demand spectra for different durations of shaking

0.00.10.20.30.40.50.60.70.80.91.0

0.00 0.10 0.20 0.30 0.40

Spectral displacement (m)

Sp

ectr

al a

ccel

erat

ion

(g

) Capacity Curve

5% Damped

Short Duration

Long Duration

Example Fragility Curves

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.0 0.1 0.2 0.3 0.4

Spectral Response (m)

Per

cent

age

of b

uild

ings

exc

eedi

ng

dam

age

stat

e

Slight

Moderate

Extensive

Complete

Transition from Physical Damage to Financial Loss

There exists for each member type a damage level corresponding to the drift

There exists for each member type a retrofit procedure corresponding to each damage level

There exists for each retrofit procedure a corresponding retrofit cost

% $

Retrofit Options

Reinforced Concrete Column:

Slight damage:Damage: Hairline cracks.Repair: Epoxy injection.

Moderate:Damage: Extensive wide Repair: jacketing, epoxy injection.

Severe:Damage:Repair: ?

Collapsed:Damage: Repair: ?

Retrofit Cost at Story Level Based on Member Damage

Repair Cost

Repair/Intervention CostColumn Beam Floor Partition Cladding Glazing Ceiling MEP

1st Floor Negligible 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Slight 0.000 0.000 0.048 0.031 0.000 0.101 0.065 0.031

Moderate 0.057 0.000 0.150 0.147 0.067 0.304 0.229 0.080

Extensive 0.622 0.746 1.204 0.631 0.532 0.421 0.797 0.840

Complete 1.055 1.186 1.204 0.950 0.920 0.842 1.056 1.052

2nd Floor Negligible 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Slight 0.000 0.000 0.048 0.031 0.000 0.101 0.065 0.031

Moderate 0.066 0.000 0.150 0.147 0.058 0.304 0.229 0.080

Extensive 0.653 0.746 1.204 0.631 0.500 0.421 0.797 0.840

Complete 1.078 1.186 1.204 0.950 0.870 0.842 1.056 1.052

3rd Floor Negligible 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Slight 0.000 0.000 0.048 0.031 0.000 0.101 0.065 0.031

Moderate 0.066 0.000 0.150 0.147 0.058 0.304 0.229 0.080

Extensive 0.653 0.746 1.204 0.631 0.500 0.421 0.797 0.840

Complete 1.078 1.186 1.204 0.950 0.870 0.842 1.056 1.052

Column Beam Floor Partition Cladding Glazing Ceiling MEP1st Floor 88320 54148 228865 38595 20730 232018 42439 281160

2nd Floor 77288 54148 228865 38595 11000 232018 42439 281160

3rd Floor 77288 54148 228865 38595 11000 232018 42439 281160

Damage Functions (Physical and Material)

Material Loss

Physical Damage

Spectral Displacement, in

Da

ma

ge

Ra

tio mean

mean+

mean-

Spectral DIsplacement, in

Da

ma

ge

, m

illi

on

$

mean

mean+

mean-

Calibrated Damage Curves

0%

20%

40%

60%

80%

100%

0 2 4 6 8 10 12

Spectral Displacement, cm

MD

R,

%RC Shear w/MRF, Mid

RC Shear w/MRF, High

Concrete MRF, Low-Rise

Concrete MRF, Mid-Rise

Concrete MRF, High-Rise

Risk Analysis

Calculation of material losses for probable (scenario) earthquakes

Calculation of risk curves

Assessment of regional risk

Determination of premiums based on regional risk by insurers

Column/Wall as Ratios Vulnerability Indexes

0.000

0.001

0.001

0.002

0.002

0.003

0.000 0.005 0.010 0.015 0.020 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

X-direction

Column/Wall as Ratios Vulnerability Indexes

0.000

0.001

0.001

0.002

0.002

0.003

0.003

0.004

0.000 0.005 0.010 0.015 0.020 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

Y-direction

Judgment for Adequacy Checked by Complete3-D Analysis - Horizontal Axis > 0.0025

0

0.0005

0.001

0.0015

0.002

0.0025

0 0.005 0.01 0.015 0.02 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

X-directionAdequate

Horizontal Axis Generally < 0.0025

0

0.0005

0.001

0.0015

0.002

0.0025

0 0.005 0.01 0.015 0.02 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

X-directionTo be Strengthened

Judgment for Adequacy Checked by Complete3-D Analysis - Horizontal Axis > 0.0025

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0 0.005 0.01 0.015 0.02 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

Y-directionAdequate

Horizontal Axis Generally < 0.0025

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0 0.005 0.01 0.015 0.02 0.025

Column + Wall Index

Par

titi

on

Wal

l In

dex

Y-directionTo be Strengthened