EVALUATION OF EXISTING STRUCTURES

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EVALUATION OF EXISTING STRUCTURES
COST Action C25 Sustainability of Constructions
Integrated Approach to Life-Time Structural
Engineering 1st WG3 Meeting Eindhoven
(Netherlands), 13-14 December 2006

• MUTLU SEÇER ÖZGÜR BOZDAG
• DOKUZ EYLÜL UNIVERSITY
• ENGINEERING FACULTY
• CIVIL ENGINEERING DEPARTMENT
• STRUCTURAL ENGINEERING DIVISION
• IZMIR, TURKEY
• 13 DECEMBER 2006

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• Background and Expertise on WG3/WP9
• Mutlu SEÇER, M.Sc. (TR)
• M.Sc. Thesis Nonlinear Analysis Methods of
  Steel Structures
• Ph.D. Thesis (On going study) Investigation of
  Stress Strain Time Relationships in Framed
  Structures
• Special Interests
• Second Order Analysis Techniques in Steel Frames
• Analysis of Semi Rigid Connections in Steel
  Frames
• Analysis of Imperfections
• Stability of Structures
• Practical Advanced Analysis Methods
• Performance Based Analysis of Structures

3

• Background and Expertise on WG3/WP9
• Özgür BOZDAG, M.Sc. (TR)
• M.Sc. Thesis Dynamic Analysis of Retaining
  Structures
• Ph.D. Thesis (On going study) Energy Based
  Performance Anaysis of Structures
• Special Interests
• Performance Based Analysis of RC Structures
• Earthquake Engineering and Structural Dynamics
• Soil Structure Interaction
• Rehabiliation of Masonry Structures

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• Ongoing research activity at the national level
  on the topic of WG3
• TUBITAK Project
• Sustainability of Constructions
• The Aim of the Study is
• Investigation of The New Constructions Built in
  Historic Centers
• (In The Meaning of Sustainability of The
  Characteristics of Present Urban Form)

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• Special Interests in WP of the WG3
• WP9 Monitoring of life-cycle performance
• Maintenance, repair and rehabilitation techniques
  and planning
• Guidelines for the planning of Maintenance,
  Repair and Rehabilitation
• Survey and condition assessment of structures
  (safety and functionality)
• Guidelines survey and condition assessment of
  structures

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INTRODUCTION

• Our country is located on one of the most active
  earthquake areas on earth. Nearly 95 of Turkey
  is on very risky seismic zones. Therefore
  high-magnitude earthquakes commonly occur in
  Turkey. The structures suffer a very high amount
  of damage during these seismic activities and
  earthquakes cause widespread destruction.
• Major seismic events during the past decade, such
  as those occurring in Turkey
• Erzincan, Turkey (1992)
• Kocaeli, Turkey (1999)
• Duzce, Turkey (1999)
• Bingol, Turkey (2004)
• have continued to demonstrate the destructive
  power of earthquakes, with destruction of
  engineered buildings, bridges, industrial and
  port facilities as well as giving rise to great
  economic losses.

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INTRODUCTION

• As a result
• The need to improve seismic performance of the
  built environment through the development of
  performance-oriented procedures and guidelines
  has been recently highlighted.

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Performance Check of Structures

• How will a structure perform when subjected to a
  given level of earthquake?
• Definition of structural performance
• Definition of earthquake level
• Determination of performance level

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Performance Check of Structures

• Recently released guidelines for Seismic
  Rehabilitation of Buildings
• ATC-40
• FEMA 273, 356, 440 (ATC-55)
• TERDC 2006
• (Turkish Earthquake Resistant Design Code)

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Types of Performance Checks

• Methods for Obtaining Lateral Load Capacity of
  Structures
• Linear Static Analysis
• Linear Dynamic Analysis
• Nonlinear Static Analysis
• (Pushover Analysis)
• Nonlinear Dynamic Analysis

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Why Do Pushover Analysis?

• Design Earthquakes cause nonlinear behavior
• Better understand building behavior- Identify
  weak elements with plastic hinge formation and
  order.- Realistic prediction of element demands
• Less conservative acceptance criteria can be used
  than linear analysis.

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Performance Check Using Pushover

• Construct Pushover curve
• Select earthquake level(s) to check and construct
  their spectrum curves
• Decide the performance level(s) (i.e. IO, LS,
  CP)
• Verify structural performance with guidelines
• Capacity Spectrum Method (ATC-40)
• Displacement Coefficient Method (FEMA 273)
• TERDC 2006 (Turkish Earthquake Resistant Design
  Code)

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CASE STUDY 1 PERFORMANCE ANALYSIS OF THE
EXISTING RC MILITARY BUILDING
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Description of Building

• Number of Stories 4
• Strength of Concrete 14.9 MPa
• Steel Grade
• Beams St-III (fy420 MPa)
• Columns St-I (fy220 MPa)
• Soil Class Z3 (according to TERDC)
• Earthquake Zone 1 (according to TERDC)
• Earthquake Level Strong Earthquake (Probability
  of exceedence in 50 years is greater than 10)
• Selected Performance Objective Life Safety

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Computer Model of Structure
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Capacity Curve - Y Direction
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Determination of Earthquake Displacement Demand

• Using FEMA 356 Displacement Coefficient Method

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Performance of the structure is not enough under
considered earthquake.
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CASE STUDY 2 REHABILIATION OF HISTORICAL
MASONRY MILITARY BUILDING
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DESCRIPTION OF BUILDING
The building was used as school building in early
1900s as seen in the photo. After 1950s,
building was given to military services.
The drawing prepared for perfromance analysis of
masonry building.
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DYNAMIC MODEL OF STRUCTURE
Lumped Mass Model of The Building The Wall
Weights are higher than Slab Weights and, they
can not be neglegcted in the lumped mass model.
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Performance of The Structure

• Shear capacity of each floor is not enough for
  resisting earthquake loads.
• The Building is going to be retrofitted.

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Rehabilitation of The Structure

• Rehabilitation of structural walls
• Rehabilitation of slabs
• Rehabilitation of foundation

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Performance of The Structure After Rehabilitation

• Shear capacity of each floor is enough for
  resisting earthquake loads.

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THANKS FOR YOUR PATIENCE...