Catalyzing Innovation in Performance-Based Design for Disaster Resilient Buildings and Structures
- 1. Dr. Naveed Anwar Catalyzing Innovation in Performance-Based Design for Disaster Resilient Buildings and Structures Naveed Anwar, PhD
- 2. Dr. Naveed Anwar 2 Excellence the quality of being outstanding or extremely good
- 3. Dr. Naveed Anwar 3 To be Excellent, something must be above average, better than standard, and of higher performance
- 4. Dr. Naveed Anwar 4 What a Structural Engineer said ! Hardy Cross, 1885-1959
- 5. Dr. Naveed Anwar 5 Building Industry relies on Codes and Standards • Specify requirements • Give acceptable solutions • Prescribe (detailed) procedures, rules, limits • Mostly based on experience and not always rational • Spirit of the code to provide Public Safety and Convenience • Compliance to letter of the code is indented to meet the spirit
- 6. Dr. Naveed Anwar 6 The First Code - Hammurabi's (1772 BC) Clause 229: If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death. Implicit Requirements Consequence of non-Performance Explicit Collapse Performance
- 7. Dr. Naveed Anwar 7 Public Safety and the Codes - “In case you build a new house, you must also make a parapet for your roof, that you may not place bloodguilt upon your house because someone falling might fall from it” Modern Codes, c2000 Prescriptive Law of Moses (1300 BC) The Bible, Book of Deuteronomy, Chapter 22, Verse 8 Performance Oriented Ref: Teh Kem, Associate Prof. NUS
- 8. Dr. Naveed Anwar Formal, Modern Buildings Codes 8 “Rebuilding of London Act” after the “Great Fire of London” in 1666 AD. In 1680 AD, “The Laws of Indies” Spanish Crown London Building Act of 1844. In USA, the City of Baltimore first building code in 1859. In 1904, a Handbook of the Baltimore City In 1908 , a formal building code was drafted and adopted. The Internatio nal Building Code (IBC) by (ICC). European Union, the Eurocodes .
- 9. Dr. Naveed Anwar 9 Ancient masterpieces were built before the modern codes Master builders had freedom to dream and to realize them
- 10. Dr. Naveed Anwar Public Safety and Disaster Resilience
- 11. Dr. Naveed Anwar 11 Population Urbanization and Un- planned development Inappropriate Built Environment Lack of Resources for Communities Natural or Man-made Phenomena Disaster Hazard ExposureVulnerability To reduce risk of disaster and increase safety, we need tp estimate hazard properly, and Reduce Vulnerability Risk
- 12. Dr. Naveed Anwar 12 How modern codes intent to ensure “Safety” • Define appropriate/estimated hazard or load levels • Prescribe limits on structural systems, members, materials • Define procedures for analysis and design • Provide rules for detailing • Provide specifications for construction and monitoring •Hope that all of this will lead to reduced vulnerability and safer structures …
- 13. Dr. Naveed Anwar The Modern Codes – With “intent” to make buildings safe for public 13 (ACI 318 – 14) Extremely Detailed prescriptions and equations using seemingly arbitrary, rounded limits with implicit meaning (IS 456-2000)
- 14. Dr. Naveed Anwar The General Structural Code Families 14 UBC, IBC ACI, PCI, CRSI, ASCE, AISI, AASHTO BS, SG, IS, MNBC, NBC, PBC, …. Euro-codes China, USSR, Japan
- 15. Dr. Naveed Anwar 15 Prescriptive Codes – A Shelter • Public • Will the building be safe? • Owner • Will the building collapse/ will it be damaged ? • Can I use the building after a given earthquake? • How much will repair cost? • How long will it take to repair? • Can I make building that will not be damaged and will not collapse • Structural Engineer: • Not sure, but I did follow the “Code” As long as engineers follow the code, they can be sheltered by its provisions
- 16. Dr. Naveed Anwar 16 A Move Towards Performance Based • Prescriptive Codes restrict and discourage innovation • Performance Based approach encourages and liberates it Objective Requirements Prescribed Solution Objective Requirements Alternate Solution
- 17. Dr. Naveed Anwar 17 Motivation for PBD • Lack of explicit performance in design codes is primary motivation for performance based design • Performance based methods require the designer to assess how a building is likely perform extreme events and their correct application will help to identify unsafe designs. • Enables arbitrary restrictions to be lifted and provides scope for the development of innovative, safer and more cost-effective solutions
- 18. Dr. Naveed Anwar Ensuring Explicit Safety Performance (And increase Disaster Resilience)
- 19. Dr. Naveed Anwar 19 Common Hazards leading to Safety Concerns
- 20. Dr. Naveed Anwar 20 Indicator Level Earthquake Related Wind Related Water Related Fire Related Global Drift, Overturning, Sliding Drift, Overturning, Sliding, Uplift Sliding, Floatation Stability Member Strength, Ductility, Deformation Strength, Deformation, Water tightness, Strength, Deformation Fire rating Connection Strength, Ductility, Stability Strength, Stability Strength, Stability, water tightness Fire rating Material Ductility, Strength Wind pervious Water proof/ water resistant Fire proof, fire resistant Broad Performance Indicators
- 21. Dr. Naveed Anwar 21 Integrated Disaster Resilient Design Design Process Step Design Considerations Earthquakes Cyclones, Typhoons Floods Landslide Location Plan&Layout Appropriate Material Strength& integrity Evacuation Location DesignElements Material Selection Strength& integrity Debris Location BasicDesign MitigationPlan MaterialUsage Location MitigationPlan Site Selection Construction Practices Architectural Planning Structural Design Plumbing Design Electrical Waste Disposal Material Selection Regional Planning
- 23. Dr. Naveed Anwar 23 Performance based design can be applied to any type of loads, but was initaily developed and targeted for earthquake loads Earthquakes as a Catalyst for PBD
- 24. Dr. Naveed Anwar 24 Explicit Performance Objective in PBD Performance based design investigates at least two performance objectives explicitly Service-level Assessment Ensure continuity of service for frequent hazards (Earthquake having a return period of about 50) Collapse-level Assessment Ensure Collapse prevention under extreme hazards (the largest earthquake with a return period of 2500 years) Codes arbitrary implicit “Design Level”
- 25. Dr. Naveed Anwar 25 Performance Level Definitions Owner Will the building be safe? Can I use the building after the hazard? How much will repair cost in case of damage? How long will it take to repair? Engineer Free to choose solutions, but ensure amount of yielding, buckling, cracking, permanent deformation, acceleration, that structure, members and materials experiences Need a third party to ensure public safety and realistic Performance Guidelines Peer Review
- 26. Dr. Naveed Anwar 26 Performance Objectives fro Sesimic Design Level of Earthquake Seismic Performance Objective Frequent/Service (SLE): 50% probability of exceedance in 30 years (43-year return period) Serviceability: Structure to remain essentially elastic with minor damage to structural and non-structural elements Design Basis Earthquake (DBE): 10% probability of exceedance in 50 years (475-year return period) Code Level: Moderate structural damage; extensive repairs may be required Maximum Considered Earthquake (MCE): 2% probability of exceedance in 50 years (2475-year return period) Collapse Prevention: Extensive structural damage; repairs are required and may not be economically feasible
- 27. Dr. Naveed Anwar Define Performance Levels 27 Based on FEMA 451 B
- 28. Dr. Naveed Anwar Link the Hazard to Performance Levels 28 Structural Displacement LoadingSeverity Resta urant Resta urant Resta urant Hazard Vulnerability Consequences
- 29. Dr. Naveed Anwar 29 How to Work with PBD
- 30. Dr. Naveed Anwar Progression and Future Directions in PBD
- 31. Dr. Naveed Anwar Design Approaches Intuitive Design Code Based Design Performance Based Design Consequences and Risk Based Design Resilience Based Design
- 32. Dr. Naveed Anwar Design Approaches Intuitive Design Code Based Design Performance Based Design Consequences and Risk Based Design Resilience Based Design
- 33. Dr. Naveed Anwar Design Approaches Intuitive Design Code Based Design Performance Based Design Consequences and Risk Based Design Resilience Based Design
- 34. Dr. Naveed Anwar Design Approaches Intuitive Design Code Based Design Performance Based Design Consequence and Risk Based Design Resilience Based Design
- 35. Dr. Naveed Anwar Design Approaches Intuitive Design Code Based Design Performance Based Design Consequence s and Risk Based Design Resilience Based Design
- 36. Dr. Naveed Anwar Green Buildings Resilient Buildings 36 Main authors : Arup Supported by USRC and many others
- 37. Dr. Naveed Anwar 37 • Explicit confirmation of higher or expected performance level using innovative solutions Performance Based Design • Get the best “value” for resourcesValue Engineering • Provide an independent view and confirmation Peer Review
- 38. Dr. Naveed Anwar Some Case Studies
- 39. Dr. Naveed Anwar 39 PBD and Asian Institute of Technology, AIT • Research labs to support innovation • More than 70 tall building projects in Asia • Carried out for several developers and structural engineers • Many of which further reviewed by third-party experts based in the USA
- 40. Dr. Naveed Anwar 40 Gramercy Residences (72-story) Knightsbridge Residences (64-story) TrumpTower (56-story) Milano Residences Some Projects in Makati, Philippines
- 41. Dr. Naveed Anwar 41 Park Terraces • Located in Makati City, Philippines • Two 50-story towers, one 62 story tower • Remove perimeter beams, for better View • First application of buckling restrained brace (BRB) system in Philippines
- 42. Dr. Naveed Anwar 42 42 Acqua Private Residences Mandaluyong City, Philippines NiagaraTower (42-story ) SutherlandTower (44-story) DettifossTower (46-story) LivingstoneTower (53-story)
- 43. Dr. Naveed Anwar 43 Ninoy Acquino International Airport Terminal 1 • Performance Based Approach used for Disaster Resilience • Traditional Code Based Review would make it unfeasible • Seismic evaluation and retrofit design • Evaluate for “Collapse Prevention” structural performance level under strong earthquakes 43
- 44. Dr. Naveed Anwar 44 Star View Residences Bangkok
- 45. Dr. Naveed Anwar 45 R & D to Enhance Performance
- 46. Dr. Naveed Anwar 46 Application of PBD to PC Hybrid Buildings
- 48. Dr. Naveed Anwar 48 The Plan
- 49. Dr. Naveed Anwar 49 Modeled and Design for Two Approaches 117.9 m (38 Stories) Transfer Beams Residential Floors Cast-in-Place Shear Walls Precast Concrete Walls RC Walls Car Parking Floors RC Columns Roof Code Based Design – Linear Model PBD – Nonlinear Model
- 50. Dr. Naveed Anwar 50 PBD Findings and Fixes No. Components Actions Comments for Seismic Evaluation at MCE level 1 Shear Walls Flexure OK Shear Increase horizontal reinforcements and wall thickness 2 Columns Flexure OK Shear Increase horizontal reinforcements and column size 3 RC Walls Flexure Increase confinement reinforcements (2 Stories) Shear Increase horizontal reinforcements (2 Stories) 4 PC Walls Flexure Increase confinement reinforcements (2 Stories) Shear Increase horizontal reinforcements (2 Stories) 5 Plies Axial OK 6 Foundations Flexure OK Shear OK 7 Transfer Beams Flexure Increase longitudinal reinforcements Shear Increase horizontal reinforcements 8 Coupling Beams Flexure OK Shear Increase horizontal reinforcements
- 51. Dr. Naveed Anwar 51 Client PBD Value Engineering Peer Review Basic Design Public Officials Design Codes and Guidelines High performance, Higher safety higher value, cost effective Sustainable Excellence in Construction