a comparative study on existing tall buildings with...
TRANSCRIPT
A Comparative Study on Exist ing Tall Buildings with Structural Irregularities
and its effect on Cost And Performance
Engr. Rex J. Sirilan
Sysquared & Associates, Inc.
• Irregular structure contains irregular distribution of mass,
stiffness and strength or due to geometrical configurations.
• Irregularities directly affects seismic performance.
• Failure of structural elements are concentrated at irregularities.
B A C K G R O U N D
HORIZONTAL IRREGULARITIES
VERTICAL IRREGULARITIES
A. ACCIDENTAL TORSIONAL CHECK
𝐴𝑥 =δ𝑚𝑎𝑥
1.2 δ𝑎𝑣𝑒
2< 3.0
B. 25 % BACK-UP FRAME CHECK
Special moment frame is required to resist at least 25% of design
seismic forces.
BUILDING AMPLIFICATION
EXISTING ALVEO PROJECTS
PERFORMANCE AND COST
ANALYSIS
CASE STUDY 1:
56 Flrs 42 Flrs 32 Flrs 48 Flrs 48 Flrs 43 Flrs 48 Flrs 28 Flrs
Sequoia Portico Solinea Solstice Kroma Verve High Park Abreeza
BUILDINGS IN REVIEW
SEQUIOA PORTICO SOLINEA SOLSTICE
TYPICAL FLOOR PLAN
KROMA VERVE HIGH PARK ABREEZA
TYPICAL FLOOR PLAN
SEQUOIA
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)5.77 5.51 2.69
TYPETRANSLATIO
N IN X
TRANSLATIO
N IN YROTATION
ETABS MODEL
-
20
40
60
80
100
120
140
160
180
200
0 0.5 1 1.5 2
Bu
ildin
g H
eig
ht
(m)
Drift Ratio (%)
Interstory Drift
Spec X
Spec Y
Limit
-
20
40
60
80
100
120
140
160
180
200
0.0 0.5
Bu
ildin
g H
eig
ht
(m)
Displacement (m)
Building Displacement
Wind X
Wind Y
Limit
BUILDING
PERFORMANCE
SEQUOIA TOWER
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATIO
N FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAMEN/A* N/A*
PORTICO
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)6.53 6.15 5.62
TYPETRANSLATIO
N IN X
TRANSLATIO
N IN YROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATION
FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAMEN/A* N/A*
PORTICO TOWER
-
50
100
150
200
-0.5 0.5 1.5 2.5
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
SPEC 1
SPEC 2
LIMIT
-
50
100
150
0.0 0.1 0.2 0.3 0.4 0.5
BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
WIND X
WIND Y
LIMIT
BUILDING PERFORMANCE
SOLINEA
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)3.23 2.60 2.21
TYPETRANSLATIO
N IN X
TRANSLATIO
N IN Y
TRANSLATIO
N IN Y
+ ROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATIO
N FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAME2.46 9TH – 12TH
SOLINEA TOWER
(20)
-
20
40
60
80
100
120
-0.5 0.5 1.5 2.5
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
SPEC 1
SPEC 2
LIMIT
(20)
-
20
40
60
80
100
0.0 0.1 0.2 0.3 0.4BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
WIND X
WIND Y
LIMIT
BUILDING PERFORMANCE
SOLSTICE
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)6.40 5.53 4.58
TYPETRANSLATIO
N IN Y
TRANSLATIO
N IN X
TRANSLATIO
N IN X
+ ROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATION
FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAME2.73 2F-4F
SOLSTICE TOWERBUILDING PERFORMANCE
-
50
100
150
0.0 0.5
BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
Wind X
Wind Y
Limit
-
50
100
150
0 1 2
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
Spec X
Spec Y
Limit
KROMA
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)5.55 5.39 4.72
TYPETRANSLATIO
N IN Y
TRANSLATIO
N IN XROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATION
FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAME3.27 3F-10F
KROMA TOWER
-
50
100
150
200
0 0.5 1 1.5 2
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
Spec X
Spec Y
Limit
-
50
100
150
200
0.0 0.5BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
Wind X
Wind Y
Limit
BUILDING PERFORMANCE
VERVE
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)5.77 4.68 3.49
TYPETRANSLATIO
N IN YROTATION
TRANSLATIO
N IN X
+ ROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATION
FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAME3.27 3F
VERVE TOWERBUILDING PERFORMANCE
-
50
100
150
200
0 1 2
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
Spec X
Spec Y
Limit
-
50
100
150
200
0.0 0.5BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
Wind X
Wind Y
Limit
HIGH PARK
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)5.85 5.32 4.73
TYPETRANSLATIO
N IN XROTATION
TRANSLATIO
N IN X
+ ROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANCEMAXIMUM
AMPLIFICATION
FACTOR
LEVEL
TORSIONAL 1.21 2F-8F
25% BACK-UP
FRAME4.63 2F
HIGH PARK TOWERBUILDING PERFORMANCE
-
20
40
60
80
100
120
140
-1 0 1 2
BU
ILD
ING
HEI
GH
T (M
)
DRIFT RATIO (%)
Interstory Drift
Spec X
Spec Y
Limit
(50)
-
50
100
150
0.0 0.5BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
Wind X
Wind Y
Limit
ABREEZA
MODAL RESPONSE
MODE 1 2 3
ELEVATIO
N
PERIOD, T
(s)3.12 3.05 2.12
TYPETRANSLATIO
N IN X
TRANSLATIO
N IN YROTATION
ETABS MODEL
BUILDING AMPLIFICATION FACTORS
PERFORMANC
E
MAXIMUM
AMPLIFICATIO
N FACTOR
LEVEL
TORSIONAL 1.00 NONE
25% BACK-UP
FRAME1.00 NONE
ABREZZA PLACEBUILDING PERFORMANCE
0
20
40
60
80
100
0.00 1.00 2.00 3.00BU
ILD
ING
HEI
GH
T (M
)
DRIFT (%)
Interstory Drift
SPEC 1
SPEC 2
LIMIT
-10
10
30
50
70
90
0 0.1 0.2 0.3
BU
ILD
ING
HEI
GH
T (M
)
DISPLACEMENT (M)
Building Displacement
WIND X
WIND Y
LIMIT
TABULATION OF RESULTS
COMPARATIVE STUDY
TYPICAL FLOOR
PLAN
PROJECT NAME ABREEZA SOLINEA PORTICO VERVE SOLSTICE HIGH PARK KROMA SEQUOIA
LOCATION DAVAO CITY CEBU CITY PASIG CITY TAGUIG CITY MAKATI CITY QUEZON CITY MAKATI CITY TAGUIG CITY
I. BUILDING AMPLIFICATION FACTORS
1.1 Torsional
Irregularity1 1 1 1 1
1.21
(2nd-8th Flr)1 1
1.2 Dual System
(25% Back Up
Frame)1
2.46
(9th-12th Flr)N/A
3.27
(3rd Flr)
2.73
(2nd-4th Flr)
4.63
(2nd Flr)
3.27
(3rd-10th Flr)N/A
II. ESTIMATE
2.1 CONSTRUCTION
FLOOR AREA (m2) 28312 26841 58558 73441 71759 95219 85581 99111
2.2 CONCRETE (m3/m2) 0.37 0.38 0.44 0.43 0.40 0.43 0.45 0.42
2.3 REBAR RATIO
(Kg/m2) 62.08 69.60 85.99 86.00 85.00 95.66 92.84 92.40
COST COMPARISON
PROJECTNUMBER OF
AMPLIFICATIONS
REBAR RATIO
(kg/𝑚2)
High Park Tower 1 8 95.66
Kroma 7 92.84
Verve Tower 1 7 86.00
Solstice Tower 1 3 85.00
Solinea Tower 2 3 69.60
Abreeza Place 0 62.08
0
2
4
6
8
10
0.00 20.00 40.00 60.00 80.00 100.00 120.00
Number of Amplifications vs. Rebar Ratio
High Park Tower 1 is the most irregular structure with the highest rebar ratio.
NUMBER OF AMPLIFICATIONS VS REBAR RATIO
SLAB SYSTEM VS REBAR RATIO
PROJECTTYPE OF SLAB
SYSTEMREBAR RATIO (kg/𝑚2)
Sequoia PT- Slab 92.40
Kroma Flat Slab 92.84
High Park Tower 1 Conv. Slab 95.66
Verve Tower 1 Conv. Slab 86.00
Portico Tower 1 Conv. Slab 85.99
Solstice Tower 1 Conv. Slab 85.00
Solinea Tower 2 Conv. Slab 69.60
VIBE TOWER
EFFECT OF ECCENTRICITY ON
STRUCTURAL COST
CASE STUDY 2:
TYPICAL TOWER LAYOUT
TOTAL ESTIMATED COST OF CONCRETE AND REBAR
Scheme 1 Scheme 2 Scheme 3 Scheme 494
95
96
97
98
99
100
101
102
PER
CEN
TAG
E (%
) -
20
40
60
80
100
120
140
0.50 0.60 0.70 0.80 0.90 1.00
Bu
ildin
g H
eigh
t (m
)
Distance, e (m)
SCHEME 1
SCHEME 2
SCHEME 3
SCHEME 4
CENTER OF MASS & RIGIDITY DISTANCE
The most economical scheme:
SCHEME 2 with the smallest eccentric distance
The highest costing scheme:
SCHEME 3 with the largest eccentric distance
CENTER OF MASS & CENTER OF RIGIDITY DISTANCE
-
20
40
60
80
100
120
140
0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
Bu
ildin
g H
eigh
t (m
)
Drift Ratio (%)
Interstory Drift under Spec Y
SCHEME 1
SCHEME 2
SCHEME 3
SCHEME 4
Limit
-
20
40
60
80
100
120
140
0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
Bu
ildin
g H
eigh
t (m
)
Drift Ratio (%)
Interstory Drift under Spec X
SCHEME 1
SCHEME 2
SCHEME 3
SCHEME 4
Limit
INTERSTORY DRIFT
• Flexible structure within the code prescribed limits is ideal for an economical
design.
• Minimize the eccentric distance between Center of Mass and Center of Rigidity
to reduced the structural cost.
• Structural irregularities has large concentration of stresses and expensive to
construct.
• Eliminate penalties from 25% back up frame Codal requirement by using
Performance Based Design.
FINDINGS
THANK YOU!
LIFE IS LIKE RIDING
A BICYCLE,
TO KEEP YOUR
BALANCE,
YOU MUST KEEP
MOVING.
-Albert Einstein