Recent Experience in Turkey for Building Vulnerability and Estimating Damage Losses P. Gülkan and A. Yakut Middle East Technical University

Residential/Commercial Building under Construction

DAMAGE IS ALWAYS ATTRIBUTABLE TO A COMBINATION OF ADVERSE CONDITIONS

Code violations

DAMAGE RELATIONSHIP WITH HEIGHT: R/C BUILDINGS IN GÖLCÜK

REINFORCED CONCRETE BUILDINGS IN GÖLCÜK

R/C BUILDINGS UP TO THREE STORIES TALL

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: q Geology q Seismology q Earthquake and structural engineering q 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. material losses Hazard Event nucleation Calculation of intensity Vulnerability Damage calculation Building stock Geotechnical background Principal Components of Earthquake Models

Hazard Assessment Softer formation Bedrock Attenuation Amplification

Modeling Seismic Sources 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

Soil Type and Amplification Sand and silt Stiff clay Rock Stiff clay Rock

Comparison of Vulnerability Analyses ATC Intensity is MMI Expert Opinion Curves HAZUS 1997 Spectral Intensity Expert Opinion Curves Expert Opinion Vulnerability Analytic Vulnerability Judgment Based Hazard Parameter Empirical Hazard Parameter ACM 2000 Spectral Intensity Objectively Developed Curves

Development of Damage Functions q Determination of typical structural types and their features based on design drawings q Analysis of earthquake response q Development of damage functions for each building type on basis of member damage q Determination of retrofit strategies and associated costs q Assembly of damage functions for each building type

Typical Structural Features q Structural characteristics ä Material type ä Plan area, story height, span widths, number of spans ä Number of stories q Design of Typical Buildings ä Design calculations ä Material properties ä Blueprint drawings

USA: Building Types q Steel ä Moment resisting ä Braced Frame q Reinforced concrete ä Moment resisting ä Shear wall q Precast concrete ä Frame ä Panel ä Tilt-Up Timber Reinf. Conc. Frame/Wall Steel frame Tilt-up Reinf. 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

Push-over Analysis

Element Level Damageability D%

ANALYTICAL ESTIMATION OF FRAGILITY

Transition from Physical Damage to Financial Loss q There exists for each member type a damage level corresponding to the drift q There exists for each member type a retrofit procedure corresponding to each damage level q 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 Cost

Damage Functions (Physical and Material) Material Loss Physical Damage Spectral DIsplacement, in Damage, million $ mean mean+ mean-

Calibrated Damage Curves

Risk Analysis q Calculation of material losses for probable (scenario) earthquakes q Calculation of risk curves q Assessment of regional risk q Determination of premiums based on regional risk by insurers

Column/Wall as Ratios Vulnerability Indexes

Judgment for Adequacy Checked by Complete 3-D Analysis - Horizontal Axis >

Horizontal Axis Generally <

Judgment for Adequacy Checked by Complete 3-D Analysis - Horizontal Axis >

Horizontal Axis Generally <