Transcript Overview of ATC-63 Project “Quantification of Building

2007 PEER Annual Meeting
Overview of ATC-63 Project
“Quantification of Building System and
Response Parameters”
Charles A. Kircher, Ph.D., P.E.
Kircher & Associates
Palo Alto, California
January 19, 2007
ATC-63 Project
ATC -63 Project Objectives
• Primary – Create a methodology for determining
Seismic Performance Factors (SPF’s) “that, when
properly implemented in the design process, will result
in the equivalent earthquake performance of buildings
having different structural systems” (i.e., different
lateral-force-resisting systems)
• Secondary – Evaluate a sufficient number of different
lateral-force-resisting systems to provide a basis for
Seismic Code committees (e.g., BSSC PUC) to develop
a simpler set of lateral-force-resisting systems and
more rational SPF’s (and related design criteria) that
would more reliably achieve the inherent earthquake
safety performance objectives of building codes
ATC-63 Project
Project Organization
FEMA
FEMA
Michael Mahoney
Robert Hanson (Adv.)
Applied Technology Council
PRP Members
TOP Management
Chris Rojahn (PED)
Jon Heintz (PTM)
William Holmes (PQC)
PMC Members
Charels Kircher (Chair)
Greg Deierlein – Stanford
M. Constantinou – Buffalo
John Hooper - MKA
James Harris – HA
Allan Porush - URS
TOP Management Committee
Project Executive Director (Chair)
Project Technical Monitor
Project Quality Control Monitor
ATC-63 Project Management Committee
Project Technical Director (Chair)
Five Members
Project Review Panel
Twelve Members
Working Groups
Technical Consultants
Phipps (Chair)
Elnashai - MAE
Ghosh - SKGA
Gilsanz- GMS
Hamburger - SGH
Hayes - NIST
Holmes – R&C
Klingner - UT
Line - AFPA
Manley - AISI
Reinhorn - UB
Rojahn - ATC
Sabelli - DASSE
ATC Staff
Technical Support
Administration
Working Groups
Stanford – NDA
SUNY – NSA/NCA
Filiatrault – Wood
Krawinkler - AAC
ATC-63 Project
Project Tasks and Schedule
0
3
6
9
MONTHS
12 15
21
24

Task 1:
Development of Project Work Plan
Task 2:
Project Management and Oversight
Task 3:
Review Relevant Research-

Task 4:
Development of a Recommended
Seismic Performance Factor
Methodology

Task 5:
Conduct Benchmark Evaluations of
Recommended Seismic Performance
Factor Methodology
Task 6:
Sample Evaluation of Selected Structural
Systems (Verification Process)
Task 7:
Development of a Draft Guidance
Document
Task 8:
Plan and Conduct Workshop (deferred until year 3)
Task 9:
Preparation of Project Report and
Related Outreach Materials (deferred until year 3)
ATC-63 Project Management Committee Meetings:
ATC-63 Project Review Panel Meetings
18




X
X
X
Y
X
X
X
Y
: Task milestone/completion
ATC-63 Project
Seismic-Force-Resisting Systems (Tasks 5 and 6)
• Reinforced-Concrete Structures
– 4-Story SMF, IMF and OMF
– 12-Story IMF/OMF and Shear
Wall (Core Wall)
– Parametric Study of RC Frames
• 1, 2, 4, 8, 12 and 20 stories
Concrete – Stanford
Gregory Deierlein
Curt Haselton
Abbie Liel
Brian Dean
Jason Chou
Ashpica Chhabra
John Hooper (MKA)
Brian Morgan (MKA)
• Space vs. perimeter
configurations
• Drift Limits (1% - 4%)
• Weak story irregularities
(Code limits: 80%, 65%)
ATC-63 Project
Seismic-Force-Resisting Systems (Tasks 5 and 6)
• Wood Structures (CUREE):
– Townhouse – Superior,
typical, poor quality
– Apartment – Superior, typical
and poor quality
Wood - Buffalo
Andre Filiatrault
Ioannis Christovasilis
Hiroshi Isoda
Michael Constantino
AAC - Stanford
– Other (Japanese Home,
Templeton Hospital)
Helmut Krawinkler
Farzin Zareian
Kevin Haas
Dimitiros Lignos
• Autoclaved Aerated Concrete
(AAC) Test Structures
Steel - Stanford
• Steel Structures:
– 4-Story (RBS) SMF (IMF, OMF)
Greg Deierlein
Abbie Liel
Helmut Krawinkler
Dimitiros Lignos
Curt Haselton
ATC-63 Project
Elements of the Methodology
Ground
Motions
Analysis
Methods
Methodology
Test Data
Design Information
Requirements
Requirements
Peer Review
Requirements
ATC-63 Project
Guiding Principals
• New Buildings – Methodology applies to the seismic-forceresisting system of new buildings and may not be appropriate for
non-building structures and does not apply to nonstructural
systems.
• NEHRP Provisions – Methodology is based on design criteria,
detailing requirements, etc. of the NEHRP Provisions (i.e., ASCE
7-05 as adopted by the BSSC for future NEHRP Provisions
development) and, by reference, applicable design standards
• Life Safety – Methodology is based on life safety performance
(only) and does not address damage protection and functionality
issues (e.g., I = 1.0 will be assumed)
• Structure Collapse – Life safety performance is achieved by
providing uniform protection against local or global collapse of
the seismic-force-resisting system for MCE ground motions
• Ground Motions – MCE ground motions are based on the
spectral response parameters of the NEHRP Provisions,
including site class effects
ATC-63 Project
Methodology Overview
• Conceptual Framework – Methodology adopts the concepts and
definitions of seismic performance factors (SPF’s) of the NEHRP
Provisions (e.g., global pushover concept as described in the
Commentary of FEMA 450 )
• Failure Modes – Methodology evaluates structural collapse defined
by system-dependent local and global modes of failure
• Collapse Probability – Methodology evaluates structural collapse
probability considering response and capacity variability (and
epistemic and aleatory uncertainty)
• Archetypical Systems – Methodology defines “archetypical”
structural systems that have configurations typical of a given type
or class of lateral-force-resisting system
• Analytical Models – Methodology incorporates models (of
archetypical systems) that have sufficient complexity to
realistically represent global performance of actual building
systems considering nonlinear inelastic behavior of seismic-forceresisting components
• Analytical Methods – Methodology utilizes nonlinear analysis
methods (i.e., pushover and incremental dynamic analysis)
ATC-63 Project
Definition of Seismic Performance Factors (SPF’s)
(from FEMA 450 Commentary)
Base Shear
Design Earthquake
Ground Motions
Cd
R = Response Modification
Coefficient = VE/V
Cd = Deflection Amplification
Factor = d/de
O = System Over-strength
Factor = VY/V = DY/de
VE
Rd
VY
R
Pushover
Curve
0
V
de
DY
DE
d
Roof Displacement
ATC-63 Project
SPF’s and MCE Collapse Margin
Spectral Acceleration (g)
Median
10th Percentile
SC1
SA-Based
Collapse
Fragility
Collapse Level
Ground Motions
T
MCE Ground
Motions
Margin
SM1
SD-Based
Collapse
Fragility
1.5R
1.5Cd
SY1
Margin
Median
O
Cs
10th Percentile
SDe
SDM
1
Spectral Displacement
SDC1
ATC-63 Project
Example Collapse Fragility – One Data Point
Building
(Joe’s Bar)
Incipient
Collapse
Scaled Ground
Motion Record
Joe’s
+
Beer!
Food!
Acceleration (g's)
0.6
1989 Loma Prieta - Corralitos (128 deg.)
0.3
=
0
-0.3
-0.6
0
2
4
6
8
10
12
Time (Seconds)
14
16
18
20
Evaluation of a single structure (one configuration/set
of performance properties) to failure using one ground
motion record scaled to effect incipient collapse
ATC-63 Project
Example Collapse Fragility – Comprehensive
and Representative Collapse Data
Incipient
Building
Collapse
(Joe’s
Bar)
Incipient
Building
Collapse
(Joe’s
Bar)
Incipient
Building
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Food!
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Food!
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Food!
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground Motion
Collapse
(Joe’s
Bar)
Incipient
Food!
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Incipient
Building
Joe’s Food!Beer!
Ground Motion
Collapse
(Joe’s
Bar)
Incipient
Food!
Building
Joe’s
Beer!
Ground
Motion
Collapse
(Joe’s
Bar)
Joe’s Food!Beer!
Ground Motion
Joe’s Food!Beer!
Ground Motion
Joe’s Food!Beer!
Joe’s Food!Beer!
Comprehensive
and representative
collapse data
1989 Loma Prieta - Corralitos (128 deg.)
0.3
1989 Loma Prieta - Corralitos (128 deg.)
2
0
4
-0.3
-0.6
+
0
0.6 6
14
16
8
10
12
Time (Seconds)
0.3
2
0
4
-0.3
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
+
0
18
=
0.6 6
14
16
2
0
8
10
12
Time (Seconds)
4
-0.6
18
0.6 6
14
16
8
10
12
Time (Seconds)
0.3
0
-0.6
0
0.6 6
14
16
0.3
2
0
4
-0.3
-0.6
0
0.6 6
18
=
2
0
14
16
8
10
12
Time (Seconds)
4
-0.3
0
20
18
=
0.6 6
14
16
0
8
10
12
Time (Seconds)
4
18
=
20
=
1989 Loma Prieta - Corralitos (128 deg.)
0.3
2
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.6
Food!
Beer!
Food!
=
20
1989 Loma Prieta - Corralitos (128 deg.)
8
10
12
Time (Seconds)
Acceleration (g's)
4
Acceleration (g's)
2
-0.3
18
1989 Loma Prieta - Corralitos (128 deg.)
+
Comprehensive
+
+
models of building
+
configuration/performance
properties evaluated with
representative earthquake records
0
=
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
=
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
=
20
1989 Loma Prieta - Corralitos (128 deg.)
0.3
-0.3
=
20
1989 Loma Prieta - Corralitos (128 deg.)
Acceleration (g's)
+
0
8
10
12
Time (Seconds)
0.3
Acceleration (g's)
-0.6
0.6 6
20
Acceleration (g's)
4
18
Acceleration (g's)
0
16
Acceleration (g's)
0.3
2
-0.3
14
1989 Loma Prieta - Corralitos (128 deg.)
Acceleration (g's)
+
0
8
10
12
Time (Seconds)
Acceleration (g's)
-0.6
0.6 6
Acceleration (g's)
4
Acceleration (g's)
0
Acceleration (g's)
0.3
2
-0.3
Acceleration (g's)
0
Acceleration (g's)
-0.6
Acceleration (g's)
-0.3
+
=
0.6
Acceleration (g's)
0
Acceleration (g's)
+
Acceleration (g's)
0.6
6
14
8
10
12
Time (Seconds)
-0.3
16
18
20
=
1989 Loma Prieta - Corralitos (128 deg.)
14
16
18
20
-0.6
0
2
4
6
8
10
12
Time (Seconds)
14
16
18
=
20
ATC-63 Project
Notional Collapse Fragility Curve
1.0
Collapse Probability .
0.9
Comprehensive/Representative Collapse Data
Lognormal Distribution
0.8
Margin
0.7
0.6
50% probability (median)
of collapse at SC1 = 1.6 g
0.5
0.4
0.3
0.2
0.1
10% probability
of collapse at
SM1 = 0.9 g
Acceptably low
probability of
collapse (TBD)
given MCE
spectral demand
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
1-Second Spectral Acceleration (g)
ATC-63 Project
Collapse Fragility with Modeling Uncertainty
1
Cummulative Probability of Collapse
0.9
Margin
0.8
0.7
0.6
0.5
0.4
0.3
0.2
Empirical CDF
Lognormal CDF (RTR Var.)
Lognormal CDF (RTR + Modeling Var.)
0.1
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Sag.m.(T=1.0s) [g]
ATC-63 Project
ATC-63 Ground Motion Record Sets - Objectives
• Code (ASCE 7-05) Consistent – Pairs of horizontal
components “selected and scaled from individual
recorded events.” Section 16.1.3.1 of ASCE 7-05
• Very Strong Ground motions – Ground motions strong
enough to collapse new buildings
• Large Number of Records – Enough records in set to
estimate median and RTR variability (collapse fragility)
• Structure-Type Independent – Appropriate for NDA
(IDA) of variety structures with different dynamic
characteristics and performance properties
• Site/Hazard Independent – Appropriate for evaluation
of structures located at different sites/hazard levels
ATC-63 Project
Ground Motion Record Sets (PEER NGA database)
•
Far-field Record Set (Basic Set):
– 22 records (2 components each)
–
–
•
•
14 Events
Mechanisms: 9 strike-slip, 5 thrust
Near-field Record Set:
– 28 records (2 components each)
– 14 Events
– Half of records with a pulse, half without a pulse
Scale records (consistent with ASCE 7-05):
– Normalize individual records by PGV
– Anchor record set median spectral demand to
MCE demand (at period of structure)
ATC-63 Project
Response Spectra - Far-Field Record Set
1.2
MedianSpectrum
Spectrum--Far-Field
Far-FieldSet
Set
Median
+ 1 LnStdDev Spectrum - FF Set
Spectral Acceleration (g)
2.2
2
1.0
+ 2 LnStdDev Spectrum - FF Set
1.8
1.6
Std Dev Ln(Sa) - Far-Field Set
0.8
1.4
1.2
0.6
1
0.8
0.4
0.6
0.4
0.2
0.2
0
0.0
0
0.5
1
1.5
2
2.5
3
3.5
Standard Deviation - Ln (Sa)
2.4
4
Period (seconds)
ATC-63 Project
Spectral Shape – Far-Field Record Set
2.0
Epsilon - Median of Far-Field Record Set
Spectral Acceleration (g)
1.6
1.2
0.8
0.4
0.0
-0.4
-0.8
-1.2
-1.6
-2.0
0
0.5
1
1.5
2
2.5
3
3.5
4
Period (seconds)
ATC-63 Project
Comparison of Median Response Spectra at
Collapse – 4-Story R/C SMF Model Building
7.0
First 11 Collapses
First 22 Collapses
All 44 Collapses
Last 22 Collapses
Last 11 Collapses
Fundamental
period is 0.94
seconds
6.0
Sa(T=0.94s) [g]
5.0
First 11: Mean epsilon = 0.06
First 22: Mean epsilon = 0.06
All 44: Mean epsilon = 0.36
Last 22: Mean epsilon = 0.67
Last 11: Mean epsilon = 1.10
4.0
3.0
60% increase in margin due to
increase in mean epsilon (0.36 to 1.1)
2.0
1.0
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Period [seconds]
ATC-63 Project
Comparison of Collapse Fragility Curves – 4-Story
R/C SMF Model Building
1.0
First 11 Collapses
First 22 Collapses
All 44 Collapses
Last 22 Collapses
Last 11 Collapses
0.9
0.8
Probability
0.7
60% increase in margin due to
increase in mean epsilon (0.36 to 1.1)
MCE is
0.96g
0.6
0.5
10-fold decrease in margin due to
increase in mean epsilon (0.36 to 1.1)
0.4
0.3
First 11: Mean epsilon = 0.06
First 22: Mean epsilon = 0.06
All 44: Mean epsilon = 0.36
Last 22: Mean epsilon = 0.67
Last 11: Mean epsilon = 1.10
0.2
0.1
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Sa(0.94s) [g]
ATC-63 Project
Spectral Shape Factor
• The Need - Incorporation of spectral shape effect is essential to
accurate estimation of collapse margin required to achieve
acceptably low probability of collapse
• The Problem - Currently available maps of epsilon (from hazard
de-aggregation) are not directly applicable and development of
applicable maps/methods is not feasible near term
• The Solution - Alternatively, generically applicable siteindependent spectral shape factors (SSF’s) can be used to
approximate “typical” epsilon effect on spectral shape (i.e., factors
used to bias margin calculated using “epsilon-neutral” records)
• Trial Values (SSF) - Generic spectral shape factor would be a
function of system ductile capacity:
– High ductility Systems
SSF = 1.6 (e.g., R = 8)
– Moderate ductility Systems
SSF = 1.2 (e.g., R = 4)
– Low Systems
SSF = 1.0 (e.g., R = 2)
ATC-63 Project
Reinforced-Concrete (RC) Special Moment
Frame (SMF) System Example
• Purpose
– Illustrate methodology for an existing seismic-forceresisting (RC SMF) system (as if it were a new system
being proposed for the Code)
– Demonstrate validity of the methodology (show R = 8
is reasonable for RC SMF)
• Approach
– Develop comprehensive set of archetypical systems
(e.g., 18 designs) based on ASCE 7-05 (and ACI 318)
– Determine over-strength factors (O) from push over
– Determine margins from IDA’s
– Adjust margins for spectrum shape factor (epsilon)
– Evaluate margin acceptability (considering total
uncertainty (RTR + modeling + design + testing)
ATC-63 Project
Notional Flowchart of Process
Develop System
Characterize Behavior
Establish Design Provisions
Develop Archetype Models
Evaluate Collapse Performance
No
P[C] < Limit
Yes
Peer Review
ATC-63 Project
Archetype Design Configurations (18)
• Basic Set - High Seismic (SDC D) designs (6)
– Low gravity (perimeter frame) configuration
– 1, 2, 4, 8, 12 and 20-story heights
– 20-foot bay size
• Basic Set - High Seismic (SDC D) designs (6)
– High gravity (space frame) configuration
– 1, 2, 4, 8, 12 and 20-story archetypes
– 20-foot bay size
• Check Low Seismic - Low Seismic (B/C) designs (4)
– 8, 12, and 20-story heights – Low gravity (perimeter)
– 20-story height – high gravity (space frame)
• Check Bay Size - 30-foot bay designs (2)
– High Seismic (SDC D) designs
– 4-story – low gravity (perimeter frame)
– 4-story – high gravity (space frame)
ATC-63 Project
n-stories at H
Index Archetype Configuration (4-Story)
Wtrib
Wlean
M
beam
column
H1st-story
beamcolumn joint
foundation
leaning
(P-D)
column
bay size
ATC-63 Project
Summary of Archetype Design Properties
Initial Design ASCE 7-05)
Arch.
Design ID
No.
Key Archetype Design Parameters
No. of
Stories
Gravity
Loads
Seismic Design Criteria
SDC
R
T (sec.)
V/W (g)
SAMCE [T]
(g)
High Seismic and Low Gravity (Perimeter Frame) Designs
2069
1
P
D
8
0.26
0.125
1.50
2064
2
P
D
8
0.45
0.125
1.50
1003
4
P
D
8
0.81
0.092
1.11
1011
8
P
D
8
1.49
0.050
0.60
5013
12
P
D
8
2.40
0.035
0.38
5020
20
P
D
8
3.77
0.022
0.24
High Seismic and High Gravity (Space Frame) Designs
2061
1
S
D
8
0.26
0.125
1.50
1001
2
S
D
8
0.45
0.125
1.50
1008
4
S
D
8
0.81
0.092
1.11
1012
8
S
D
8
1.49
0.050
0.60
5014
12
S
D
8
2.18
0.035
0.41
5021
20
S
D
8
3.45
0.022
0.26
ATC-63 Project
Example IDA Results and Margin
(4-story, SDC D, space frame with 30-foot bays)
Sa(T=0.81s) [g]
8
6
4
2.5 Margin
(2.77/1.11)
Median Collapse Sa = 2.77g
2
0
0
MCE Sa = 1.11g
0.05
0.1
0.15
Maximum Interstory Drift Ratio
ATC-63 Project
Acceptable Collapse Margin
(based on composite uncertainty and collapse goal)
Target Collapse Probability
Composite
Uncertainty
5%
10%
15%
20%
25%
0.55
2.47
2.02
1.77
1.59
1.45
0.6
2.68
2.16
1.86
1.66
1.50
0.65
2.91
2.30
1.96
1.73
1.55
0.7
3.16
2.45
2.07
1.80
1.60
0.75
3.43
2.61
2.18
1.88
1.66
0.8
3.73
2.78
2.29
1.96
1.72
0.85
4.05
2.97
2.41
2.05
1.77
0.9
4.40
3.16
2.54
2.13
1.84
0.95
4.77
3.37
2.68
2.23
1.90
1
5.18
3.60
2.82
2.32
1.96
ATC-63 Project
Initial Results – RC SMF (ASCE 7-05)
ATC-63 Project
Re-design to Improve Collapse Margin of
Tall Buildings (12 and 20-story heights)
• Restore minimum base shear provision removed
from ASCE 7-02 (Eq. 9.5.5.2.1-3):
Cs  0.044 SDS I
Arch.
Design
ID No.
1013
1020
(I = 1.0)
Key Archetype Design Parameters
No. of
Stories
Seismic Design Criteria
Gravity
Loads
SDC
T (sec.)
V/W (g)
Reff1
Re-Design - High Seismic and Low Gravity (Perimeter Frame) Designs
12
P
D
6.4
2.13
0.044
20
P
D
4.1
3.36
0.044
Re-Design - High Seismic and High Gravity (Space Frame) Designs
SAMCE [T]
(g)
0.42
0.27
1014
12
S
D
6.4
2.13
0.044
0.42
1021
20
S
D
4.1
3.36
0.044
0.27
1. Effective value of R due to limits on the seismic coefficient, Cs.
ATC-63 Project
Revised Results – RC SMF (ASCE 7-02)
ATC-63 Project