nees quake summit thursday july 12, 2012 seismic design in massachusetts
DESCRIPTION
NEES Quake Summit Thursday July 12, 2012 Seismic Design In Massachusetts. 0.06. Eric M. Hines Principal, LeMessurier Consultants, Boston Professor of Practice, Tufts University. UBC 1970-1973. OCBF: V = 1820k SMRF: V = 753k. UBC 1976-1985. OCBF: V = 3067k SMRF: V = 1149k. - PowerPoint PPT PresentationTRANSCRIPT
NEES Quake SummitThursday July 12, 2012
Seismic DesignIn Massachusetts
Eric M. HinesPrincipal, LeMessurier Consultants, BostonProfessor of Practice, Tufts University
0.06
0
100
200
300
400
500
600
700
SOURCE-to-SITE DISTANCE (km
)
0
50
300
350
6.0
6.5
7.0
4.5 5.
0 5.5 6.
0 6.5 7.
0 7.5
MAG
NITU
DE (M
w)
24
68
10%
Con
trib
utio
n to
Haz
ardDeaggregation
for Boston2% in 50 yearsT = 1.0 sec
Deaggregationfor Los Angeles2% in 50 yearsT = 1.0 sec
0
10
20
30
40
50
60
SOURCE-to-SITE DISTANCE (km
)7.5
5.5 6.
0 6.5 7.
0 7.5 8.
0
MAG
NITU
DE (M
w)
1020
3040
% C
ontr
ibut
ion
to H
azar
d
UBC 1970-1973
OCBF: V = 1820kSMRF: V = 753k
UBC 1976-1985
OCBF: V = 3067kSMRF: V = 1149k
ATC 3-06 1978; MSBC 1997
OCBF: V = 1152kSMRF: V = 497k
988 km
IBC 2006 (USGS 2002); MSBC 20082% in 50 year, Sa for T = 1.0s
OCBF: V = 985kSMRF: V = 273k
0.06
UBC 1970-1973
UBC 1976-1985
ATC 3-06 1978;MSBC 199710% in 50 year
IBC 2006 (USGS 2002); MSBC 20082% in 50 year
SMRF OCBF
753 1820
1149 3067
497 1152
273 985
LA/Bos1.0
1.33
4.0
3.5-6.5
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 350.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
0.05
0.055
2%-50yr
City Sequence #
Pro
babi
lity
of C
olla
pse
in 5
0yrs
Southern California Northern California Pacific NW Intermountain CEUS
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 350.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
0.05
0.055
MCER
City Sequence #
Pro
babi
lity
of C
olla
pse
in 5
0yrs
Southern California Northern California Pacific NW Intermountain CEUS
NorthridgeRiverside
San Bernardino
Oakland San Jose
Concord
San Francisco
San MateoSanta Cruz
Vallejo
Santa Rosa
1 2 3 4 5 60.00
0.05
0.10
0.15
0.20
0.25 Los AngelesSan BernardinoSan DiegoOaklandSacramentoSan FranciscoSanta RosaSeattlePortlandMemphisCharleston
1976 UBC 1997 UBC1994 UBC 1997 NEHRP 2009 NEHRP
Special Moment Frame Base Shear
(Prof. L.G. Baise, Tufts University)
Hines , Baise and Swift (JSE—2011)
FILL = 20 feetVs = 600 ft/s
ORGANICS = 12 feetVs = 450 ft/s
SAND AND GRAVEL = 12 feetVs = 950 ft/s
SILTY CLAY = 90 feetVs = 800 ft/s
BEDROCK
GLACIAL TILL = 12 feetVs = 950 ft/ssoil profile adapted from: E.G. Johnson, “Geotechnical Characteristics of the Boston Area,” Civil Engineering Practice,1989
Vsavg = 695 ft/s
Site Class D:1996 Maps = Category C2002 Maps = Category B
new Mass Code maintainsspecial provisions based on40 years of practice
13’ Typ.18’
30’-0” 30’-0” 30’-0”
Concentrically Braced Frame (Typ.)
5 @ 30’-0” = 150’-0”
1’ slab overhangin each direction
5 @ 30’-0” = 150’-0”
W14x22 (Typ.)
W21x44 (Typ.)
W16x36 (Typ.)
W21x44 (Typ.)
9-Story Concentrically Braced Frame
Design loadwith 0% Eccentricity
Mass and LFRSfor ½ of building
Hines , Appel and Cheever (EJ—2009)
Hines & Fahnestock (Toronto—2010)
Reserve System Concept
Wind x 1.0
Wind x1.6
EQ x 0.7
EQ x 1.0
ASD WindASD EQ
LRFD W ind
2 4 6 8 10 12 14 16 180
500
1000
1500
2000
LRFD EQ
Bas
e Sh
ear (
kips
)
Stories
For R=3 systems MCE seismic forces are 4.5 times higher, but in the East, wind almost always controls drift.
Braced Frame with Reserve System or
Moment Frame with Stiffening System
1927 Steel FrameBuilding
3700 kips of shear capacity at Level 21 (244’)
Eastern Suite, Site Class B
0.0 0.5 1.0 1.5 2.0 2.5 3.0Period, T (sec)
0.0
0.2
0.4
0.6
0.8
Sa(g
)
0.0
0.2
0.4
0.6
0.8Sa
(g)
0.0 0.5 1.0 1.5 2.0 2.5 3.0Period, T (sec)
2002 UHS PointsIBC Site Class BEastern Suite AverageWestern Suite Average
Hines , Baise and Swift (JSE—2011)
NUREG SuiteAmplified via Boston Stiff Soil Profile
0.0 0.5 1.0 1.5 2.0 2.5 3.00.0
0.2
0.4
0.6
0.8
1.0
IBC-MCE-D: 2002 USGS
Suite Average
Period, T (sec)
Sa (g
)
3/R=3T=.69s
6/R=3T=1.35s
9/R=3T=2.07s
12/R=3T=2.94s
Hines , Baise and Swift (JSE—2011)
First Story Drift for 6-Story Models under GM6
0 4 8 12 16 20 24Time (sec)
-3
-2
-1
0
Stor
yDr
ift(%
)
-8
-6
-4
-2
0
2
Stor
yDr
ift(in
)
R=2R=4
Hines , Appel and Cheever (EJ—2009)
Behavior of 6-Story/R3 Model under GM5
1 First Fracture
t = 7.60s
First Story Drift
Drift [%
]
Time [sec]
1
Drif
t [in
]
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
-3
-2
-1
0
1
2
3
-8
-6
-4
-2
0
2
4
6
8
R
6
5
4
3
2
1
2 Second Fracture
t =19.9s2
3 Collapse
t = 25.8s3
Max Drift =5.9 in
Hines , Appel and Cheever (EJ—2009)
Behavior of 6-Story/WRS Model under GM5
t = 7.52s
First Story Drift
Drift [%
]
Time [sec]
1
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
-3
-2
-1
0
1
2
3
-8
-6
-4
-2
0
2
4
6
8
Drif
t [in
]
1
R
6
5
4
3
2
1
t = 15.4s2
2
t = 25.4s3
3Max Drift = 0.9 in
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0Scale Factor
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0Pr
obab
ility
9-Story Fragility Curves
R=2R=3R=4WRS
Hines , Appel and Cheever (EJ—2009)
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0Scale Factor
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Prob
abilit
y
3-Story Fragility Curves
R=2R=3R=4WRS
1/2 x Reserve
2 x Reserve
1-Story Low-Ductility CBF+Reserve System
Future Practice• Reserve capacity is a clear concept
(belt and suspenders), so designers can make sense of what they are doing.
• R = 3*, R = 5/5, WRS, Stiffened MRF