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Dr. Naveed Anwar
Catalyzing Innovation in Performance-Based Design for Disaster Resilient Buildings and Structures
Naveed Anwar, PhD
Dr. Naveed Anwar2
Excellencethe quality of being outstanding or
extremely good
Dr. Naveed Anwar3
To be Excellent, something must be above average, better than standard,and of higher performance
Dr. Naveed Anwar4
What a Structural Engineer said !
Hardy Cross, 1885-1959
Dr. Naveed Anwar5
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
Dr. Naveed Anwar6
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
Dr. Naveed Anwar7
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
PrescriptiveLaw of Moses (1300 BC)
The Bible, Book of Deuteronomy, Chapter 22, Verse 8
Performance Oriented
Ref: Teh Kem, Associate Prof. NUS
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 International Building Code (IBC) by (ICC).
European Union,
the Eurocodes.
Dr. Naveed Anwar9
Ancient masterpieces were built before the modern codes
Master builders had freedom to dream and to realize them
Dr. Naveed Anwar
Public Safety and Disaster Resilience
Dr. Naveed Anwar11
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
Dr. Naveed Anwar12
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 …
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)
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
Dr. Naveed Anwar15
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
Dr. Naveed Anwar16
A Move Towards Performance Based
• Prescriptive Codes restrict and discourage innovation
• Performance Based approach encourages and liberates it
Objective RequirementsPrescribed
Solution
Objective RequirementsAlternate Solution
Dr. Naveed Anwar17
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
Dr. Naveed Anwar
Ensuring Explicit Safety Performance(And increase Disaster Resilience)
Dr. Naveed Anwar19
Common Hazards leading to Safety Concerns
Dr. Naveed Anwar20
Indicator Level
Earthquake Related
Wind Related Water Related Fire Related
GlobalDrift, Overturning, Sliding
Drift, Overturning, Sliding, Uplift
Sliding, Floatation Stability
MemberStrength, Ductility, Deformation
Strength, Deformation,
Water tightness, Strength, Deformation
Fire rating
ConnectionStrength, Ductility, Stability
Strength, Stability Strength, Stability, water tightness
Fire rating
Material Ductility, Strength Wind perviousWater proof/ water resistant
Fire proof, fire resistant
Broad Performance Indicators
Dr. Naveed Anwar21
Integrated Disaster Resilient Design
Design
Process Step
Design Considerations
Earthquakes Cyclones, Typhoons Floods Landslide
Loc
atio
n
Pla
n &
La
yo
ut
Ap
pro
pria
te
Ma
teria
l
Str
en
gth
&
inte
grity
Eva
cu
atio
n
Loc
atio
n
De
sig
n E
lem
en
ts
Ma
teria
l
Se
lec
tio
n
Str
en
gth
&
inte
grity
De
bris
Loc
atio
n
Ba
sic
De
sig
n
Mitig
atio
n P
lan
Ma
teria
l U
sag
e
Loc
atio
n
Mitig
atio
n P
lan
Site Selection
Construction
Practices
Architectural Planning
Structural Design
Plumbing Design
Electrical
Waste Disposal
Material Selection
Regional Planning
Dr. Naveed Anwar22
Dr. Naveed Anwar23
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
Dr. Naveed Anwar24
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”
Dr. Naveed Anwar25
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
GuidelinesPeer Review
Dr. Naveed Anwar26
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
Dr. Naveed Anwar
Define Performance Levels
27
Based on FEMA 451 B
Dr. Naveed Anwar
Link the Hazard to Performance Levels
28
Structural Displacement
Lo
adin
g S
ever
ity
Resta
urant
Resta
urant
Resta
uran
t
Haz
ard
Vulnerability
Consequences
Dr. Naveed Anwar29
How to Work with PBD
Dr. Naveed Anwar
Progression and Future Directions in PBD
Dr. Naveed Anwar
Design Approaches
Intuitive Design
Code Based Design
Performance Based Design
Consequences and Risk Based Design
Resilience Based Design
Dr. Naveed Anwar
Design Approaches
Intuitive Design
Code Based Design
Performance Based Design
Consequences and Risk Based Design
Resilience Based Design
Dr. Naveed Anwar
Design Approaches
Intuitive Design
Code Based Design
Performance Based Design
Consequences and Risk Based Design
Resilience Based Design
Dr. Naveed Anwar
Design Approaches
Intuitive Design
Code Based Design
Performance Based Design
Consequence and Risk Based Design
Resilience Based Design
Dr. Naveed Anwar
Design Approaches
Intuitive Design
Code Based Design
Performance Based Design
Consequences and Risk Based Design
Resilience Based Design
Dr. Naveed Anwar
Green Buildings Resilient Buildings
36
Main authors : ArupSupported by USRC and many others
Dr. Naveed Anwar37
• 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
Dr. Naveed Anwar
Some Case Studies
Dr. Naveed Anwar39
PBD andAsian 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
Dr. Naveed Anwar40
Gramercy Residences
(72-story)Knightsbridge Residences
(64-story)
Trump Tower
(56-story)
Milano Residences
Some Projects in Makati, Philippines
Dr. Naveed Anwar41
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
Dr. Naveed Anwar42
42
Acqua Private ResidencesMandaluyong City,
Philippines
Niagara Tower
(42-story )
Sutherland Tower
(44-story)
Dettifoss Tower
(46-story)
Livingstone Tower
(53-story)
Dr. Naveed Anwar43
Ninoy AcquinoInternational 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
Dr. Naveed Anwar44
Star View ResidencesBangkok
Dr. Naveed Anwar45
R & D to Enhance Performance
Dr. Naveed Anwar46
Application of PBD to PC Hybrid Buildings
Dr. Naveed Anwar47
Dr. Naveed Anwar48
The Plan
Dr. Naveed Anwar49
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 FloorsRC Columns
Roof
Code Based Design – Linear Model PBD – Nonlinear Model
Dr. Naveed Anwar50
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
Dr. Naveed Anwar51
Client
PBD Value Engineering
Peer Review
Basic Design
Public Officials
Design Codes and Guidelines
High performance, Higher safetyhigher value, cost effectiveSustainable
Excellence in Construction
Dr. Naveed Anwar52
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