DEPARTMENT OF CIVIL ENGINEERING
UNIVERSITY OF BRITISH COLUMBIA, VANCOUVER
PEER-CSSC tall building case studies: Concrete core wall building
Tony Yang, Ph.D.
Assistant Professor,
University of British Columbia, Vancouver
Acknowledgements:
Jack Moehle and Yousef Bozorgnia(PEER), Andy Fry and John Hooper (MKA), Graham Powell (CSI)
2010 LATBSDC Annual meeting, May 7th 2010
Introduction
PEER SCCS Tall Building Systems
Concrete core shear wall buildings
MKA
Concrete core shear wall buildings
MKA
Core shear wall
Link beamPT slab
Prototype model
MKA
4 stories(≅ 48’)
• Residential building in Downtown Los Angeles.
42 stories (≅ 430’)
228’ 227’
108’
107’
A
A
View A-A
Building design
Building 1A(Code design)
Building 1B(PBEE design)
Building 1C(PBEE+ design)
• Designed using IBC 2006.
• Designed using 2008 LATBSDC procedure.
• Designed using PEER TBI guideline.
• All provisions were followed except the
height limit.
• All provisions were followed. Except: 1) Vmin was waived. 2) SLE was checked using 25-yr EQ (w ζ = 2.5%) instead of 43-yr EQ (w ζ = 5%). No more than 20% of the elements are allowed to reach 150% of the code specified capacity.
• Similar to 1B design Except: 1) SLE was check 43-yr EQ (w ζ = 2.5%). 2) All ductile elements such as the coupling beams and flexural yielding of the concrete walls are allowed to reach 150% of the code specified capacity.
Building 1A(Code design)
Building 1B(PBEE design)
Building 1C(PBEE+ design)
• Designed using IBC 2006.
• Designed using 2008 LATBSDC procedure.
• Designed using PEER TBI draft guideline.
Performance-based design guideline for tall
buildings
Building design
Building 1A(Code design)
Building 1B(PBEE design)
Building 1C(PBEE+ design)
• Designed using IBC 2006.
• Designed using 2008 LATBSDC procedure.
• Designed using PEER TBI draft guideline.
• B4 – L24: 24”• L25 – Roof: 21”
• B4 – L13: 28” (N-S)32” (E-W)
• L14 – L31: 24”• L32 – Roof: 21”
• B4 – L13: 32” (N-S)36” (E-W)
• L14 – L31: 24”• L32 – Roof: 21”
Wall
thic
kness
Building design: Wall vertical reinforcement
1A
1B
1C
MKA
Building design: Coupling beam reinforcement
MKA
1A
1B
1C
Building design comparison
1A: Code 1B: PBEE 1C: PBEE+
Wall: Strong Stronger Strongest
Coupling beam:
Stronger Stronger Strong
1st mode Period:
T1X = 5.2 sec
T1Y = 4.0 sec
T1X = 4.8 sec
T1Y = 3.6 sec
T1X = 4.6 sec
T1Y = 3.5 sec
24” 24” 28” 28” 32” 32”
Nonlinear analytical model
3D nonlinear dynamic finite element model (Perform3D).
Ignored the gravity system.
Nonlinear analytical model
Basement walls below grade were modeled using elastic shear wall elements (Eeff = 0.8 E)
Nonlinear analytical model
Slabs below grade were modeled using elastic shear shell element (Eeff
= 0.25 E)
Nonlinear analytical model
• Shear wall flexural behavior: Nonlinear fiber wall element with expected material property.
• Shear wall shear behavior: Nonlinear shear material.
0 2 4 6 8 10 12 14
Displacement Ductility
0
1
2
3
Vtest/Vn,ACI
PCA
HSC - SP1 Wallace test data
Wallace, Massone, Orakcal - 2006
1.5 Vn
Vexp/
Vn
Curvature ductility
Nonlinear analytical model
UCLA – J. Wallace
Analytical
Experimental
M
θ
Nonlinear dynamic analyses
3D bi-directional shaking.
GM: 5 Hazard levels.
Period [sec]0 2 4 6 8 10
0
0.5
1
1.5
2
Targ
et S
a [g]
SLE-25 (25 yr)
SLE-43 (43 yr)
DBE (475 yr)
MCE (2475 yr)
OVE (4975 yr)
Nonlinear dynamic analyses
15 pairs of GM were selected and amplitude scaled for each hazard level.
Structural response
Structural response
Structural response (MCE)
0 0.5 1 1.5 2
x 104
B4
L2
L7
L12
L17
L22
L27
L32
L37
L42
Core shear H1 [kips]
PEERTBI-1AM
Floor number [-]
MCE
0 0.5 1 1.5 2
x 104
B4
L2
L7
L12
L17
L22
L27
L32
L37
L42
Core shear H1 [kips]
Floor number [-]
PEERTBI-1BM
MCE
0 0.5 1 1.5 2
x 104
B4
L2
L7
L12
L17
L22
L27
L32
L37
L42
Core shear H1 [kips]
Floor number [-]
PEERTBI-1CM
MCE
1B has 20% more core shear force than 1A and 1C.
Demand vs. Capacity
• Normalized probability density function (pdf):
0
1
2
3
4
5
6x 10
-3
Maximum shear force [kips]
[-]
Demand
Capacity
D>C
• Let X = C - D
• When X < 0
� Failure.
• Using basic probability theory:
µX = µC - µD
σX = √(σC2 + σD
2)
Safety index
• P(system failure) = P(X):
-100 0 100 200 300 400 500 600 7000
0.5
1
1.5
2
2.5
3
3.5x 10
-3
X
[-]
Probability of failure
Area under the curve = probability of failure.
βXσX, where βX = the safety index.
X = 0
X = µX
Reserved capacity – Wall 2 shear stress (MCE)
-0.5 0 0.5 10
5
10
15
20
25
30
35
40
45
50
X - reserved strength [ksi]
Floor Number [-]
PEERTBI-1AM Wall 2
MCE
-0.5 0 0.5 1 1.50
5
10
15
20
25
30
35
40
45
50
X - reserved strength [ksi]
Floor Number [-]
PEERTBI-1BM Wall 2
MCE
0 0.5 1 1.5 20
5
10
15
20
25
30
35
40
45
50
X - reserved strength [ksi]Floor Number [-]
PEERTBI-1CM Wall 2
MCE
βx = 1.7
βx = 1.4 βx = 6.0
Structural response (MCE)
0 2 4 6 8L2
L7
L12
L17
L22
L27
L32
L37
L42
CB1D [%]
PEERTBI-1AM
Floor number [-]
MCE
0 2 4 6 8L2
L7
L12
L17
L22
L27
L32
L37
L42
CB1D [%]
Floor number [-]
PEERTBI-1BM
MCE
0 2 4 6 8L2
L7
L12
L17
L22
L27
L32
L37
L42
CB1D [%]
Floor number [-]
PEERTBI-1CM
MCE
Structural response (MCE)
0 2 4 6B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
NodeXYZ-ISDRatioH1 [%]
PEERTBI-1AM
Floor number [-]
MCE
0 2 4 6B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
NodeXYZ-ISDRatioH1 [%]
Floor number [-]
PEERTBI-1BM
MCE
0 2 4 6B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
NodeXYZ-ISDRatioH1 [%]
Floor number [-]
PEERTBI-1CM
MCE
Structural response (MCE)
0 0.5 1 1.5 2B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
PEERTBI-1AM
Floor number [-]
MCE
0 0.5 1 1.5 2B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
Floor number [-]
PEERTBI-1BM
MCE
0 0.5 1 1.5 2B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
Floor number [-]
PEERTBI-1CM
MCE
-0.25 -0.2 -0.15 -0.1 -0.05B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
PEERTBI-1AM
Floor number [-]
MCE
-0.25 -0.2 -0.15 -0.1 -0.05B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
Floor number [-]
PEERTBI-1BM
MCE
-0.25 -0.2 -0.15 -0.1 -0.05B3
L3
L8
L13
L18
L23
L28
L33
L38
L43
WallStrain01 [%]
Floor number [-]
PEERTBI-1CM
MCE
Structural response (MCE)
Amplitude scaled vs. synthetic motions
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
OVE - Scaled GM
PEERTBI-1AM
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
OVE - Simulated GM
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
PEERTBI-1BM
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
PEERTBI-1CM
0 1 2 3 4 5 6B3L3L8L13L18L23L28L33L38L43
NodeXYZ-ISDRatioH1 [%]
Amplitude scaled vs. synthetic motions
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
OVE - Scaled GM
PEERTBI-1AM
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
OVE - Simulated GM
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
PEERTBI-1BM
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
PEERTBI-1CM
0 0.5 1 1.5 2
x 104
B4L2L7L12L17L22L27L32L37L42
SectionCore-ForceH1 [kips]
Amplitude scaled vs. synthetic motions
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
OVE - Scaled GM
PEERTBI-1AM
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
OVE - Simulated GM
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
PEERTBI-1BM
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
PEERTBI-1CM
0 2 4 6 8L2L7L12L17L22L27L32L37L42
CB1D [%]
Summary and conclusions
A 42-story residential concrete core wall building was designed using three design procedures.
The response of the structures under 5 levels of earthquake shaking was analyzed.
Structural design:
Wall thickness:
Wall vertical reinforcement:
Coupling beam reinforcement:
Structural period:
Structural response:
Wall stress safety index:
Coupling beam demand:
Inter-story drift and wall edge strain:
1A < 1B < 1C
1A < 1B < 1C
1C < 1A ~ 1B
1C < 1B < 1A
1B < 1A < 1C
1A < 1B < 1C
1C < 1B < 1A
Summary and conclusions
Amplitude scaled motions vs. simulated motions:
Story drift:
Core wall forces:
Coupling beam rotation:
This leads to the need for additional research to identify the characteristic of the ground motion which promotes the inelastic action in the coupling beams.
No significant difference.
No significant difference.
Amplitude scaled > simulated.
Question?Thank you for your attention!
Contact information:
Tony [email protected]://peer.berkeley.edu/~yang