Project 07 - Reassessment of
Seismic Design Procedures and
Development of New Ground Motions
for Building
g Codes
EERI Seminar on Next Generation Attenuation Models
Dr Charles A
Dr.
A. Kircher,
Kircher Kircher & Associates
Dr. Nicolas Luco, USGS
Prof. Andrew Whittaker,, SUNY – Buffalo
Reprinted with Permission from EERI
Kircher & Associates
Consulting Engineers
Topics
• Background
B k
d – Building
B ildi C
Code
d S
Seismic
i i C
Criteria
it i
– Seismic Codes and Resource Documents
– Ground Motion Development Process
– Current ground motion criteria – Project 97
• New Ground Motion Criteria – Project
j
07
– Seismic Design Procedures Reassessment Group
• Discussion of Key Concepts
– Risk-Targeted Ground Motions
– Maximum Direction Ground Motion Intensity
– 84th Percentile Deterministic Ground motions
• Example Values of New Ground Motions
– 34 United States City Sites
EERI Seminar on Next Generation Attenuation Models
Very Early Building Code – Life Safety POV
If
a
modeler
develops
aaground
motion
If a
anbuilder
engineer
designs
house
a and
mandoes
and
builds
a house
for a for
man
attenuation
and
anhouse
earthquake
occurs and
the
an earthquake
not
makeq itsrelationship
construction
firm
and
the house
occurs (regardless
of house
collapse
collapses
and causes
the death
of theand
owner
death
the owner)
– that modeler
shall
engineer
shall
sued
of
the of
house
- that builder
shall
bebe
put
tobeto
required
equ ed
de
e op
a new
e ground
gpoor)
ou d motion
ot o
death
(orto
atdevelop
least
until
very
attenuation relationship
The The
Code
ofThe
Research,
nowc.and
forever
ofc.Litigation,
c. B.C.
now
Code
ofCode
Hammurabi,
1780
EERI Seminar on Next Generation Attenuation Models
2009 NEHRP Provisions – Life Safety (+) POV
•
Provisions
P
i i
are minimum
i i
recommended
d d requirements
i
t for
f design
d i
and construction of buildings and other structures to resist earthquake
ground motions
•
Intent of these Provisions is to provide reasonable assurance of
seismic performance:
– Avoid serious injury
j y and life loss
– Avoid loss of function in critical facilities
– Minimize nonstructural repair costs (where practical to do so)
•
Objectives addressed by:
– Avoiding structural collapse in very rare, extreme ground
shaking
– Limiting damage to structural and nonstructural systems that
could lead to injury, economic loss or loss of functions for smaller
more frequent ground motions.
EERI Seminar on Next Generation Attenuation Models
Current Model Building Codes
• National:
N i
l
– 2006 IBC - 2006 International Building Code,
International Code Council,
Council Birmingham AL
AL.
(next edition 2012 IBC)
– 2006 NFPA 5000 - 2006 Building Construction and
Safety Code, NFPA 5000, National Fire Protection
Association, Quincy MA.
• Regional:
– 2006 CBC - 2006 California Building Code, California
Building Standards Commission, (previous, 2001 CBC,
based on the 1997 Uniform Building Code, International
Conference of Building
g Officials,, Whittier,, CA.
EERI Seminar on Next Generation Attenuation Models
Source Documents – Model Building Codes
• National:
– NEHRP Provisions - 2003 NEHRP Recommended
Provisions for Seismic Regulations for New Buildings and
Other Structures, Federal Emergency Management
Agency, FEMA 450. (next edition – 2009 Provisions)
– ASCE 7 - Minimum
Mi i
D
Design
i L
Loads
d ffor B
Buildings
ildi
and
d Oth
Other
Structures, ASCE 7-05, American Society of Civil
Engineers,
g
Reston, VA. 2006 ((next edition – ASCE 7-10))
• Regional:
– SEAOC Blue Book - Recommended Lateral Force
Requirements and Commentary, Seismology Committee,
Structural Engineers Association of California, 1996 Sixth
Edition and 1999 Seventh Edition
Edition.
EERI Seminar on Next Generation Attenuation Models
Seismic Codes and Source Documents - Past
NEHRP
SEAOC
Provisions
Blue Book
ASCE 7
(Seismic)
Standard
Building Code
BOCA National
Building Code
Uniform
Building Code
International Building Code
EERI Seminar on Next Generation Attenuation Models
Seismic Codes and Source Documents – Current
NEHRP
Provisions
ASCE 7
(Seismic)
IInternational
t
ti
l
Building Code
NFPA 5000
Building Code
California
C
lif
i
Building Code
EERI Seminar on Next Generation Attenuation Models
Code Development Process – Ground Motions
• Building Seismic Safety Council (BSSC) for the
NEHRP
Federal Emergency Management Agency (FEMA)
– Provisions Update
p
Committee (PUC)
(
)
• Seismic Design Procedures Reassessment
Group (SDPRG)
Provisions
ASCE 7
(Seismic))
• Structural Engineering Institute (SEI) of the
American Society of Civil Engineers (ASCE)
– Minimum Design Loads on Buildings and Other
St
Structures
t
C
Committee
itt (ASCE 7 MC)
• Task Com. Seismic Provisions (ASCE 7 SSC)
• International Code Council ((ICC))
International
Building Code
– Codes and Standards, International Building
Code - Structural Committee (IBC-S)
• Public Hearings (2009/2010 for 2012 IBC)
EERI Seminar on Next Generation Attenuation Models
Seismic Design Procedures Reassessment Group
Project 07 – Joint effort of the BSSC,
BSSC FEMA and USGS
Scope/Objectives
Members
•
Revisit products of
Project 97 in light of new
seismic hazard
information ((developed
p
by the USGS)
•
Develop revised
seismic design maps
and procedures
reflecting these new data
for inclusion in the 2009
NEHRP Procedures (and
ASCE/SEI 7-10 and
model building
g codes))
Dr. Charles A
Dr
A. Kircher
Kircher, PE (SDPRG Chair)
Dr. C. B. Crouse, PE (PUC TS-3 Chair)
Prof. Bruce R. Ellingwood, PE, Georgia Tech
Mr Ronald O.
Mr.
O Hamburger,
Hamburger SE (PUC Chair)
Prof. Robert D. Hanson, FEMA (tech. advisor)
Dr. James R. Harris, SE (ASCE 7 past Chair)
Dr. John “Jack”
Jack R. Hayes, PE, NIST (NEHRP)
Mr. William T. Holmes, SE (PUC past Chair)
Mr. John D. Hooper, SE (ASCE 7 SSC Chair)
Jeffrey
ey K. Kimball,
ba , DOE
O NNSA
S
Dr. Je
Dr. Nicolas Luco, USGS
Prof. Andrew Whittaker, SE, SUNY Buffalo
y, FEMA
Mr. Michael Mahoney,
EERI Seminar on Next Generation Attenuation Models
Proposal Development Activities and Schedule
• Technical Topics Investigated by SDPRG (task leaders):
– Level of Uniform Hazard or Risk? (Dr. Nicolas Luco)
– Ground Motion Intensity Parameter? (Prof.
(Prof Andrew Whittaker)
– Spectral Shape Definition? (Dr. James Harris)
• Proposal
oposa S
SDPRG-1R4
G
– 2009
009 NEHRP Provisions
o s o s ((Done):
o e)
– SDPRG Proposal Development – June ‘06 – Sep. ‘07
– BSSC PUC Review and Approval – Oct. ‘07 – Sep. ‘08
– BSSC M
Membership
b
hi Review
R i
and
d Approval
A
l - March
M
h 2009
• Proposal GM-CH11-1R1 – ASCE 7-10 (Done):
– ASCE 7 SSC Review and Approval – Sep.
Sep ‘08 – May ‘09
– ASCE 7 MC Review and Approval – July 2009
• Ground Motion Proposal
p
– 2012 IBC ((in the works))
EERI Seminar on Next Generation Attenuation Models
New Ground Motions
Approach and Key Components
• Revise Seismic Design Criteria:
– Seismic ground motion values (ASCE 7-10,
7-10 Section 11
11.4)
4) and
related seismic ground motion maps (ASCE 7-10, Chapter 22)
– Site-specific ground motion procedures (ASCE 7-10, Chap. 21)
• Incorporate USGS Seismic Hazard Data – New ground
motions incorporate updated seismic hazard data and
related maps developed by the USGS
• Key Technical Improvements – New ground motions include
changes in three topical areas:
– Risk-targeted ground motions (probabilistic regions)
– Direction of ground motions (Maximum direction)
– Near
Near-fault
fault (deterministic) ground motions (84th percentile)
EERI Seminar on Next Generation Attenuation Models
ASCE 7-10 and 2009 NEHRP Provisions – Differences?
• Technical
T h i l – None,
N
same concepts,
t same design
d i values
l
– Seismic design coefficients of ASCE 7-10 are exactly the same
as those of the 2009 NEHRP Provisions
• Editorial – Slightly different MCE symbol and definition (red
underline indicates text not used by ASCE 7-10):
– RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE
(MCER) GROUND MOTIONS: The most severe earthquake
effects considered by this standard as defined in Section 11.4.
– Other minor edits
• Section 11.4 formulas (and referenced MCE maps):
– ASCE 7-10 – Simpler: ASCE 7-10 defines ground motion values
(Section 11
11.4)
4) consistent with formulas of ASCE 7
7-05
05
– 2009 NEHRP Provisions – More Transparent: 2009 Provisions
define ground motion values (Section 11.4) that are consistent
with site-specific ground motion process (Chapter 21)
EERI Seminar on Next Generation Attenuation Models
Ground Motion Characterization
– Acceleration (including PGA)
– Velocity (including PGV)
– Displacement (including (PGD)
Shakiing
• Ground Motion Time Histories
• Elastic Response Spectra
– Peak response
p
of a collection of linear
single-degree-of-freedom systems with
5% viscous damping
– “S
“Smooth”
th” spectra
t used
d for
f design
d i (to
(t
represent many different possible
ground motion time histories))
g
EERI Seminar on Next Generation Attenuation Models
Time
SA
SD
Design Spectrum Shape and Parameters
Control
Period
DE
= 2/3.MCE
V/W ((Acce le ra
ation)
Acceleration
SDS
TS = SD1/SDS
SD1//T
Velocity
V = Cs W
SDS = 2/3.SMS
T0 = 0.2TS
.....= 2/3.Fa.Ss
TL = see Map
SD1 = 2/3.SM1
Long-Period Limits
.....= 2/3.Fv.S1
CS = SDS/(R/I)
Displacement Domain
SD1TL/T2
<= SD1/T(R/I)
T0
TS
Period (Seconds)
EERI Seminar on Next Generation Attenuation Models
TL
Notional Illustration of Design Earthquake (Project 97)
Spec
tral Acce
(g
g)
1-Se
econd
Sp
pectral
Acleration
celeration
n (g)
1.6
2/3 x Probabilistic [2% in 50 years]
2/3 x 1.5 x Deterministic [Median Mmax]
2/3
x 1.5
x 1994
1994
UBC
(S1) UBC
- - -(S1)
1997 UBC (SB)
1.4
1.2
1
0.8
Probabilistic
(Mod./Low Seismicity)
0.6
UBC Zone 4
0.4
Deterministic
0.2
(Near-Source)
(Near
Source)
0
1
10
100
Source Distance (km)
EERI Seminar on Next Generation Attenuation Models
1000
Notional Illustration of Design Earthquake (Project
(Project ’07)
97)
Maxim
mum Dire
ection
Spec
tral Acce
(g
g)
1-Se
econd
Sp
pectral
Acleration
celeration
n (g)
1.6
1% in
in 50
50-year
2/3 x Probabilistic [2%
years]risk
2/3 x 1.8
1.5 x Deterministic [Median Mmax]
2/3
x 1.5
x 1994
1994
UBC
(S1) UBC
- - -(S1)
1997 UBC (SB)
1.4
1.2
1
0.8
Probabilistic
(Mod./Low Seismicity)
0.6
UBC Zone 4
0.4
Deterministic
0.2
(Near-Source)
(Near
Source)
0
1
10
100
Source Distance (km)
EERI Seminar on Next Generation Attenuation Models
1000
Example Hazard Curves (USGS, 2003)
0.1
An
nnual Fre que ncy
San Francisco
SA[10%/50-yr]:
Los Angeles 0.40 g
Memphis
0.06 g
Los Angeles
Seattle
0.01
Salt Lake City
Sacramento
10% in 50 Years
Memphis
Charleston
0.001
2% in 50 Years
St. Louis
2/3 x SA[2%/50-yr]:
Los Angeles 0.45 g
Memphis
0.25 g
New York City
Chicago
0.0001
0.01
0.1
1
1-Second Spectral Acceleration (g)
EERI Seminar on Next Generation Attenuation Models
10
Probabilistic MCE Ground Motions
• Previous probabilistic MCE ground motions have
a 2% p
probability
y of being
g exceeding
g in 50 yyears
(i.e., they are of “uniform-hazard”)
• But as recognized in ATC 3-06 (1978), …
"It really is the probability of structural failure with
resultant
lt t casualties
lti th
thatt iis off concern, and
d th
the
geographical distribution of that probability is not
necessarilyy the same as the distribution of the
probability of exceeding some ground motion"
EERI Seminar on Next Generation Attenuation Models
Probabilistic MCE Ground Motions
• In other words, …
Designing for uniform-hazard (e.g., 2% in 50 years) ground
motions
ti
does
d
nott necessarily
il result
lt iin b
buildings
ildi
with
ith
uniform probability of collapse in 50 years (i.e., “uniform
risk”).
• New risk-targeted ground motions are based on a
uniform collapse risk objective:
Collapse Risk Objective – 1% in 50 years
• New risk-targeted
g
g
ground motions are calculated
assuming a generic collapse fragility that has:
10% collapse probability given MCE ground motions
EERI Seminar on Next Generation Attenuation Models
Risk-Targeted Ground Motions
Calculated iteratively by combining …
Risk Target
from Project ‘07
Building Fragility Curves
defined by
b Project ‘07
GM Hazard Curves
(e g from USGS)
(e.g.,
Prob.
ob of
o Collapse
Co apse
in 50 yrs = 1%
… via “Risk Integral” (e.g. ATC 3-06), i.e., …
EERI Seminar on Next Generation Attenuation Models
Generic Collapse Capacity / Fragility
• Based on nonlinear response history analysis by
ATC-63 Project (FEMA P695) and others …
Log. std. deviation of collapse capacity, β ≈ 0.6
10th percentile collapse capacity,
y c10% ≈ MCE ((T1)
• The latter is consistent with performance
expectation expressed in the NEHRP Provisions:
“If a structure experiences a level of ground motion 1.5
times the design
g level [[i.e.,, the MCE level],
], the
structure should have a low likelihood of collapse”
(p. 320 of 2003 NEHRP Provisions Commentary)
EERI Seminar on Next Generation Attenuation Models
•
Traditionally defined by response
spectral acceleration:
– Period dependent
•
Geomean definition:
– SQRT [Sa(X)*Sa(Y)]
– Varies
V i with
ith X
X-Y
Y orientation
i t ti
•
GMRotI50 definition (NGA):
– Complex definition
– About equal to geomean
•
Maximum direction
– Simple definition
– Peak X-Y resultant response
– Independent of X-Y
X Y orientation
0.5
0.4
Acc. in FP
direction (g
g)
Ground Motion Intensity - Background
0.3
0.2
0.1
0
-0.3 -0.2 -0.1 0
01
-0.1
-0.2
03
-0.3
-0.4
-0.5
05
EERI Seminar on Next Generation Attenuation Models
0.1
0.2
0.3 0.4 0.5
Acc in FN
Acc.
direction (g)
Intensity Example – 1999 Kocaeli Earthquake – Duzce Record
(Mw = 7.5, Strike-Slip, Df = 15.4 km, vs,30 < 276 m/s)
0.4
Component 1 (KOCAELI/DZC180)
Gro
ound Acceleration (g)
0.3
Component
p
2 (KOCAELI/DZC270)
(
)
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
0
5
10
15
20
25
30
Time (seconds)
EERI Seminar on Next Generation Attenuation Models
35
40
Intensity Example – 1-Second Response of SDOF System (5% Damping)
(1999 Kocaeli Earthquake – Duzce Record)
1.0
1-Second Response - Component 1 Direction (Kocaeli/DZC180)
1-Sec
cond Respon
nse Accel. (g
g)
0.8
1-Second Response - Component 2 Direction (Kocaeli/DZC270)
0.6
0.4
0.2
0.0
-0.2
-0.4
04
-0.6
-0.8
-1.0
0
5
10
15
20
25
30
Time (seconds)
EERI Seminar on Next Generation Attenuation Models
35
40
Intensity Example – Calculation of Geometric Mean Intensity
(1-Second Response of the Kocaeli-Duzce Record)
1.0
1-Second Response - Component 1 Direction (Kocaeli/DZC180)
1-Sec
cond Respon
nse Accel. (g
g)
0.8
0.6
0.4
0.2
1-Second Response - Component 2 Direction (Kocaeli/DZC270)
1-Second Response
Direction
(Intensity)
SA (g)
Time (s)
Component 1
0.44
8.94
Component 2
0.61
10.09
0.0
-0.2
-0.4
0.4
-0.6
-0.8
GeoMean = 0.44 x 0.61 = 0.52 g
-1.0
7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0
Time (seconds)
EERI Seminar on Next Generation Attenuation Models
Intensity Example – Comparison of Individual Component, Geometric
Mean and Arithmetic Mean Response Spectra (Kocaeli-Duzce Record)
1.4
Respons
se Spectral A
Acceleration
n (g)
Component 1 (Kocaeli/DZC180)
Component 2 (Kocaeli/DZC270)
1.2
Geometric Mean (SQRT[C1*C2])
1.0
Arithentic Mean ([C1 + C2]/2)
0.8
0.6
04
0.4
0.2
0.0
0
0.5
1
1.5
2
2.5
3
Period (seconds)
EERI Seminar on Next Generation Attenuation Models
3.5
4
1-Second Res
sponse - Com
mponent 1 Diirection
Intensity Example – Calculation of Maximum Direction Intensity
(1-Second Response of the Kocaeli-Duzce Record)
0.6
04
0.4
0.2
C2 = 0.61 g
0.0
Maximum
Direction
Intensity
= 0.61 g
-0.2
-0.4
C1 = -0.44 g
-0.6
06
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
1-Second Response - Component 2 Direction
EERI Seminar on Next Generation Attenuation Models
0.8
1.0
Intensity Example - Comparison of Geometric Mean and Maximum
Direction Response Spectra (Kocaeli-Duzce Record)
1.8
Resultant (C1,C2) - Maximum Direction (SDPRG-1R4)
1.6
Spe
ectral Accele
eration (g)
Geometric Mean (SQRT[C1*C2])
1.4
Sprectral Response (g)
Direction (Intensity)
1.2
0.2 s
0.58
0.63
0.61
0.68
1.11
Component 1
Component 2
GeoMean
Maximum
Max/GeoMean Ratio
10
1.0
0.8
0.6
1.0 s
0.44
0.61
0.52
0.61
1.18
0.4
0.2
0.0
0
0.5
1
1.5
2
2.5
3
Period (seconds)
EERI Seminar on Next Generation Attenuation Models
3.5
4
Near-Fault/Maximum Direction Ground Motions
(from Huang
Huang, Whittaker
Whittaker, Luco
Luco, 2008)
• Max/geomean ratios based on:
– Large magnitudes (M > 6.5)
– Close distance (R < 15 km)
– Average directivity (all records)
• 84th percentile response:
Maximum/Geomean Ratios
Period
(sec.)
All Records
Forward
Directivity
M di
Median
84th%
M di
Median
84th%
0
1
1.8
1.3
2.2
0.05
1
1.8
1.3
2.3
0.1
0.9
2.0
1.7
1.2
2.1
0.9
(1.1*1
1.7
.8)
1.2
2.2
1.1
– 1.8 (2.0/1.1) times median
response at short periods
0.2
0.3
1
1.9
1.3
2.5
– 1.8 (2.3/1.3) times median
response at 1 second
0.5
1.2
2.1
1.4
2.8
1
1.3
2.3
1.5
2.9
• Proposed deterministic MCE:
2
1.3
1.3
22.5
2.3
3
1.6
2.9
1.4
(1.3*1
2.6
.8)
1.7
3.1
1.4
2.7
1.7
3
– 84th percentile (1.8 x median) in
lieu of 1.5 x median
3
4
EERI Seminar on Next Generation Attenuation Models
Building Collapse – Design Considerations
Bi directional versus uni
Bi-directional
uni-axial
axial application of ground motions
• Records applied along a single axis are approximately
20% less likely to collapse a structure as compared to a
bi-axial application of the same records:
– “Incremental dynamic analysis of wood frame buildings”
study
t d (Christovasilis
(Ch i t
ili ett al.,
l EESD,
EESD 2008)
– ATC-63 Project - Based on studies of light wood frame, SMF
RC and OMF RC buildings (C3D = 1.2)
• Why (are bi-directional ground motions more critical)?
– In general, 3-D models (and real structures), can fail in any
direction (e.g., collapse can occur due to failure of framing on
either the X or Y axis, or other X-Y orientation)
– The stronger component (of each record) tends to govern
collapse
p and fails the structure in the direction of application
pp
EERI Seminar on Next Generation Attenuation Models
Maximum Direction Intensity
• Simple, record-orientation independent measure of ground
motion record intensity
– Peak response of bi-directional SDOF (2DOF) lollypop
– Readily converted from relations based on geomean intensity
• Appropriate for ELF (2-D) Design:
– Peak X-Y response appropriate for design of structures to
resist possible collapse in any horizontal direction
• Appropriate for scaling records for time history analysis:
– ASCE 7
7-10
10 (and the 2009 NEHRP Provisions) now scale
records to match target spectrum by a factor of 1.0 (rather
than 1.3 factor of ASCE 7-05)
EERI Seminar on Next Generation Attenuation Models
Comparison of Geomean and Maximum Direction Response Spectra
of the Kocaeli-Duzce Record and NGA ground motions
1.8
Resultant (C1,C2) - Maximum Direction (SDPRG-1R4)
1.6
Geometric Mean (SQRT[C1*C2])
NGA Median (M7
(M7.5,
5 R = 15
15.4
4 km
km, Vs30 = 276 m/s)
Spe
ectral Accele
eration (g)
1.4
1.2
10
1.0
0.8
0.6
0.4
0.2
0.0
0
0.5
1
1.5
2
2.5
3
Period (seconds)
EERI Seminar on Next Generation Attenuation Models
3.5
4
Properties of (all) 11 Strike-Slip Records in the PEER NGA
Database of Mw > 7, Df < 20 km, 180 m/sec < vs,30 < 760 m/s
Source Characterisitcs
Earthquake
Year
Name
Record
Station
Mag.
(Mw)
Distance Df (km)
BJ
Fault
Campbell Mechanism
Site Conditions
Site
Class
vs,30
(m/sec.)
1992
Landers
Coolwater
7.3
19.7
20.0
Strike-slip
D
271
1992
Landers
Joshua Tree
7.3
11.0
11.4
Strike-slip
C
379
1992
Landers
Lucerne
7.3
2.2
3.7
Strike-slip
C
685
1999
K
Kocaeli,
li T
Turkey
k
A lik
Arcelik
75
7.5
10 6
10.6
13 5
13.5
St ik li
Strike-slip
C
523
1999
Kocaeli, Turkey
Duzce
7.5
13.6
15.4
Strike-slip
D
276
1999
Kocaeli, Turkey
Yarimca
7.5
1.4
5.3
Strike-slip
D
297
1999
D ce T
Duzce,
Turkey
rke
Bolu
71
7.1
12 0
12.0
12 4
12.4
St ik li
Strike-slip
D
326
1999
Duzce, Turkey
Duzce
7.1
0.0
6.6
Strike-slip
D
276
1990
Manjil, Iran
Abbar
7.4
12.6
13.0
Strike-slip
C
724
1999
Hector Mine
Hector
71
7.1
10 4
10.4
12 0
12.0
Strike slip
Strike-slip
C
685
2002
Denali, Alaska
TAPS Pump St. #10
7.9
0.2
3.8
Strike-slip
D
329
7.37
8.5
10.6
Average Value of Eleven Records
EERI Seminar on Next Generation Attenuation Models
434
Comparison of Spectra (Geomean Intensity)
All Strike-Slip Records (11) in the PEER NGA Database of Mw > 7,
7 Df
< 20 km, 180 m/sec < vs,30 < 760 m/s and NGA Ground Motions
1.4
Recorded Ground Motions - Average of 11 spectra
Spectra
al Acceleratio
on (g)
1.2
NGA Relations - Average of 11 mean spectra
NGA Relations - Average of 11 median spectra
1.0
NGA Relations - Average of 11 84th-%ile spectra
0.8
0.6
0.4
0.2
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Period (seconds)
EERI Seminar on Next Generation Attenuation Models
3.5
4.0
Example – Map of New Ground Motions
SDC C
SDC D
SDC D
SDC D
.5
11
2
SDC B
>
60
-1
12
45
-6
0
5
30
-4
0
-3
-2
20
SDC A
10
0
-1
0
0
.5
1 Second MCE Spectral Acceleration (Site Class D)
1-Second
SDC E
EERI Seminar on Next Generation Attenuation Models
Comparison of Seismic Design Values
• 34 Ci
City Si
Sites iin the
h C
Continental
i
lU
United
i dS
States
– Selection of regions most at risk:
• High seismic regions (Nor Cal
Cal, So Cal
Cal, PNW)
• High population areas of high/moderate/low
seismic regions (Intermountain and CEUS)
– Selection of City sites:
• Major city of regional county or metropolitan area
• Nearest
N
t USGS h
hazard
d grid
id point
i t tto center
t off city
it
• Average Regional or National values:
– Weight seismic design value of associated county or
metropolitan area population
• Assume Default Soil Type
yp ((Site Class D))
EERI Seminar on Next Generation Attenuation Models
Map showing selected United States city sites (34) used to
compare ground motions (WUS faults shown with red lines)
EERI Seminar on Next Generation Attenuation Models
Map showing selected United States city sites (34) and new 1second MCE ground motions (WUS faults shown with red lines)
EERI Seminar on Next Generation Attenuation Models
Map showing selected Northern California city sites (10) used
to compare ground motions (WUS faults shown with red lines)
EERI Seminar on Next Generation Attenuation Models
Northern California City Sites
Location and associated county population data
Name
Latitude
Longitude
O kl d
Oakland
37 80
37.80
-122.25
122 25
Al
Alameda
d
Concord
37.95
-122.00
Contra Costa
955,810
Monterey
36.60
-121.90
Monterey
421,333
S
Sacramento
t
38 60
38.60
-121.50
121 50
S
Sacramento
t
San Francisco
37.75
-122.40
San Francisco
776,733
San Mateo
37.55
-122.30
San Mateo
741,444
S J
San
Jose
37 35
37.35
-121.90
121 90
S t Cl
Santa
Clara
1 802 328
1,802,328
Santa Cruz
36.95
-122.05
Santa Cruz
275,359
Vallejo
38.10
-122.25
Solano
423,473
Santa Rosa
38 45
38.45
Total Pop - N. California
-122.70
122 70
Sonoma
489 290
489,290
14,108,451
Name
Total Pop - 10 Counties
EERI Seminar on Next Generation Attenuation Models
Population
1 502 759
1,502,759
1 233 449
1,233,449
8,621,978
Map showing Oakland City Site and Hayward Fault
You are here
Oakland City Site
EERI Seminar on Next Generation Attenuation Models
Map showing San Mateo Site and San Andreas Fault
You are here
San Mateo Site
EERI Seminar on Next Generation Attenuation Models
Northern California City Sites
Comparison
C
i
off 1
1-second
d design
d i
values
l
(SD1) and
d MCE parameters
t
for
f
Site Class D, return periods and 50-year collapse risk probabilities
S 1D (g)
Return
Period
(years)
50-Year
Collapse
Prob.
1.01
0.75
832
2.4%
0 99
0.99
0 98
0.98
0 73
0.73
1 054
1,054
1 9%
1.9%
1.50
0.59
0.95
0.93
2,189
1.0%
0.35
1.81
0.26
1.12
0.60
3,805
1.0%
San Francisco
0 64
0.64
1 50
1.50
0 85
0.85
0 99
0.99
0 64
0.64
1 064
1,064
1 9%
1.9%
San Mateo
0.86
1.50
1.06
0.92
0.86
1,441
1.3%
San Jose
0.60
1.50
0.72
1.09
0.60
1,262
2.0%
Santa Cruz
0 60
0.60
1 50
1.50
0 64
0.64
0 98
0.98
0 60
0.60
2 012
2,012
1 1%
1.1%
Vallejo
0.60
1.50
0.65
1.08
0.60
1,838
1.5%
Santa Rosa
1.04
1.50
1.42
0.90
1.04
1,135
1.5%
Nor Cal Average
0.65
1.54
0.81
1.02
0.71
1,616
1.7%
Design
MCE (2009 NEHRP Provisions )
S D1 (g)
Fv
S 1UH (g)
C R1
Oakland
0.75
1.50
1.07
Concord
0 73
0.73
1 50
1.50
Monterey
0.56
Sacramento
City
(Site Location)
EERI Seminar on Next Generation Attenuation Models
Northern California City Sites
Comparison
C
i
off 1
1-second
d design
d i
ground
d motions
ti
(SD1) with
ith prior
i
(ASCE 7-05) values and older Code Values (Site Class D)
1.25(1.5)Z
Cv
SD1 - ASCE 7
1994 UBC
1997 UBC
ASCE 7-98 ASCE 7-05 ASCE 7-10
Oakland
0.75
1.04
0.64
0.60
0.75
Concord
0.75
0.77
0.74
0.65
0.73
Monterey
0.75
0.77
0.67
0.61
0.56
Sacramento
0.56
0.54
0.28
0.31
0.35
San Francisco
0.75
0.74
0.70
0.68
0.64
San Mateo
0.75
0.95
0.99
0.90
0.86
San Jose
0.75
0.69
0.60
0.60
0.60
Santa Cruz
0.75
0.72
0.61
0.60
0.60
Vallejo
0.75
0.87
0.60
0.60
0.60
Santa Rosa
0.75
1.28
0.86
0.83
1.04
NoCal Average
0.73
0.81
0.64
0.61
0.65
City
(Site Location)
EERI Seminar on Next Generation Attenuation Models
Northern California City Sites
Comparison
C
i
off short-period
h t
i d design
d i
ground
d motions
ti
(SDS) with
ith
prior (ASCE 7-05) values and older Code values (Site Class D)
2.75*Z
Ca
SDS - ASCE 7
1994 UBC
1997 UBC
ASCE 7-98 ASCE 7-05 ASCE 7-10
Oakland
1.10
1.43
1.08
1.06
1.24
Concord
1.10
1.10
1.26
1.23
1.38
Monterey
1.10
1.10
1.15
0.97
1.02
Sacramento
0.83
0.90
0.51
0.52
0.57
San Francisco
1.10
1.10
1.00
1.00
1.00
San Mateo
1.10
1.28
1.11
1.17
1.23
San Jose
1.10
1.10
1.00
1.00
1.00
Santa Cruz
1.10
1.10
1.04
1.00
1.01
Vallejo
1.10
1.19
1.00
1.00
1.00
Santa Rosa
1.10
1.65
1.37
1.37
1.67
NoCal Average
1.06
1.18
1.01
1.00
1.08
City
(Site Location)
EERI Seminar on Next Generation Attenuation Models
Comparison of Short-Period Design Ground Motions
Comparison of average values of current (ASCE 7-10) and prior
(ASCE 7-05) ground motions, and older Codes for each region and
all 34 selected sites in the continental United States
United States
Region
Ca
SDS - ASCE 7
1994 UBC 1997 UBC 7-98(7-02)
7-05
7-10
2.75*Z
Southern CA
1 10
1.10
1 25
1.25
1 06
1.06
1 16
1.16
1 22
1.22
Northern CA
1.06
1.18
1.01
1.00
1.08
Pacific NW
0.83
0.90
0.90
0.84
0.83
Intermountain
0.68
0.80
0.72
0.70
0.65
CEUS
0.31
0.40
0.39
0.36
0.29
0.69
0.80
0.72
0.73
0.72
All Regions
EERI Seminar on Next Generation Attenuation Models
Comparison of Short-Period Design Ground Motions
1.6
1994 UBC
SDS, 2.5Ca, o
or 2.75Z (g)
1.4
1997 UBC
ASCE 7
7-98
98 (7
(7-02)
02)
1.2
ASCE 7-05
ASCE 7-10
1.0
08
0.8
0.6
0.4
0.2
0.0
Southern
CA (11)
Northern Pacific NW Mountain
CA (10)
(4)
(4)
CEUS (5)
Region of United States
EERI Seminar on Next Generation Attenuation Models
Average All (34)
Comparison of 1-Second Design Ground Motions
Comparison of average values of current (ASCE 7
7-10)
10) and prior
(ASCE 7-05) ground motions, and older Codes for each region and
all 34 selected sites in the continental United States
United States
Region
Cv
SD1 - ASCE 7
1994 UBC 1997 UBC 7-98 (7-02)
7-05
7-10
1.25(1.5)Z
Southern CA
0 75
0.75
0 83
0.83
0 63
0.63
0 65
0.65
0 70
0.70
Northern CA
0.73
0.81
0.64
0.61
0.65
Pacific NW
0.56
0.54
0.46
0.44
0.49
Intermountain
0.47
0.46
0.41
0.39
0.34
CEUS
0.21
0.24
0.16
0.14
0.14
0.47
0.52
0.39
0.38
0.40
All Regions
EERI Seminar on Next Generation Attenuation Models
Comparison of 1-Second Design Ground Motions
1.0
1994 UBC
1997 UBC
ASCE 7
7-98
98 (7
(7-02)
02)
ASCE 7-05
ASCE 7-10
0.9
SD1, Cv, orr 1.25(1.5)Z
0.8
0.7
0.6
05
0.5
0.4
0.3
0.2
0.1
0.0
Southern
CA (11)
Northern
CA (10)
Pacific NW
(4)
Mountain
(4)
CEUS (5)
Region of the United States
EERI Seminar on Next Generation Attenuation Models
Average All (34)
Closing Comments
• On-Going
O G i Process
P
– New ground motions of ASCE 7-10 (and the 2009
NEHRP Provisions) must still be approved for use in
model building codes (e.g., 2012 IBC)
• A Word of Caution (for building design)
– New USGS hazard data and maps (e.g., based on new
NGA relations, etc.) should be used with new building
design procedures (ASCE 7-10)
• User Friendly
– GIS tools (Google) and web-based software (USGS)
will greatly simplify implementation of new design
values maps
p and p
procedures
EERI Seminar on Next Generation Attenuation Models