8th hellenic national conference of steel structures
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Structural behavior and robustness assessment of tall buildings: the case of diagrid systemsTRANSCRIPT
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Giulia MilanaPierluigi OlmatiKonstantinos GkoumasFranco Bontempi
Sapienza University of RomeDipartimento di Ingegneria Strutturale e Geotecnica
8th Hellenic National Conference of Steel Structures Tripoli (Greece) 2-4 October 2014
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 2
SustainabilityOverview
SUSTAINABILITY
SOCIAL
ENVIRONMENTAL
ECONOMIC
SUSTAINABLE DEVELOPMENT: “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” (Brundtland Commission, 1987)
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Steel Material• 40% of resources
from recycling• Manufacturing
process with controlled environmental impact
• Material durability• High recycling rate
Construction Phase
• prefabrication/ offsite manufacture
Design and Service Life• Weight reduction of structure• Creation of versatile spaces• Longevity and robustness of
steel components• Simple incorporation of
renewable energy generation systems
End of Life• Easy dismantling• Reusability/Reciclability
Source: Foster + Partners Hearst Tower USA, 2000 - 2006
SUSTAINABILITY
IN
STRUCTURES
Material
Used
Resource
Efficient
Site
Planning
Non
Pollution
Energy
Efficiency
Structural
Form
SustainabilityUse of steel and structural form
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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SustainabilityTall buildings
Ali, M. M., Moon, K. S. (2007). Structural Development in Tall Buildings: Current Trends and Future Prospects. Architectural Science Review, Vol. 50, pp. 205-223.
Interior structures
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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SustainabilityTall buildings
Ali, M. M., Moon, K. S. (2007). Structural Development in Tall Buildings: Current Trends and Future Prospects. Architectural Science Review, Vol. 50, pp. 205-223.
Interior structures Exterior structures
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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SustainabilityDiagrid structures
Capital Gate, Abu Dhabi - RMJM
Milan Trade Fair - Fuksas Atlas Building, Netherlands - Rafael Vinoly ArchitectsWesthafen, Frankfurt Tower - Schneider & Schumacher
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Diagrid structureDiagrid module
Mele, E., Toreno, M., Brandonisio, G. and Del Luca, A. (2014). Diagrid structures for tall buildings: case studies and design considerations. The Structural Design of Tall and Special Buildings. Wiley Online Library, Vol. 23, No. 2, pp. 124-145.
effect of gravity load
effect of overturning moment
effect of shear force
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Diagrid structureInitial configuration and diagrid schemes
Outrigger Structure Diagrid Structures
42° 60° 75°
160
m
36 m
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Original Structure:Outrigger
Improved Structure:Diagrid
PerimetralStructure
InternalStructure
Numerical resultsStructural configuration
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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SLS Dead Gk Tamp Qk Qn W+X W-X W+Y W-Y
COMB5 1 1 1 0,7 0,5 1 - - -
COMB6 1 1 1 0,7 0,5 - 1 - -
COMB7 1 1 1 0,7 0,5 - - 1 -
COMB8 1 1 1 0,7 0,5 - - - 1
ULS Dead Gk Tamp Qk Qn W+X W-X W+Y W-Y
COMB5 1,3 1,3 1,3 1,05 0,75 1,5 - - -
COMB6 1,3 1,3 1,3 1,05 0,75 - 1,5 - -
COMB7 1,3 1,3 1,3 1,05 0,75 - - 1,5 -
COMB8 1,3 1,3 1,3 1,05 0,75 - - - 1,5
Acronym Description Color
Outrigger Outrigger Structure
Diagrid 42°Diagrid Structure with inclination of diagonal members of 42°
Diagrid 60°Diagrid Structure with inclination of diagonal members of 60°
Diagrid 75°Diagrid Structure with inclination of diagonal members of 75°
Outrigger 42° 60° 75°
P(ton)
8052 6523 5931 5389
Saving(%)
- 19 26 33
0
1000
2000
3000
4000
5000
6000
7000
8000
9000Weight
P (
ton
)
Numerical resultsAnalyses and comparisons
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsModal analysis
T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12
Outrigger 3.741908 3.624657 2.478095 1.162387 1.084865 0.795965 NaN NaN NaN NaN NaN NaN
Diagrid 42° 3.105204 3.083854 1.724092 0.994648 0.958515 0.782728 NaN NaN NaN NaN NaN NaN
Diagrid 60° 3.308391 3.286263 1.941394 1.028297 0.989485 0.943294 NaN NaN NaN NaN NaN NaN
Diagrid 75° 3.650044 3.614059 2.824054 1.273738 1.236856 1.175041 NaN NaN NaN NaN NaN NaN
0.25
0.75
1.25
1.75
2.25
2.75
3.25
3.75
First six periods
T (
s)
Traslational in Y
direction
Traslational in X
direction
Rotationalaround Z
axis
Traslational in Y
direction
Traslational in X
direction
Rotationalaround Z
axis
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsSLS - load combinations
SLS Dead Gk Tamp Qk Qn W+X W-X W+Y W-Y
COMB5 1 1 1 0,7 0,5 1 - - -
COMB6 1 1 1 0,7 0,5 - 1 - -
COMB7 1 1 1 0,7 0,5 - - 1 -
COMB8 1 1 1 0,7 0,5 - - - 1
HORIZONTAL DISPLACEMENTS
COMB
Out
rigge
r
Dia
grid
42°
Dia
grid
60°
Dia
grid
75°
Acronym Description Color
Outrigger Outrigger Structure
Diagrid 42°
Diagrid Structure with inclination of diagonal members of
42°
Diagrid 60°
Diagrid Structure with inclination of diagonal members of
60°
Diagrid 75°
Diagrid Structure with inclination of diagonal members of
75°
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsHorizontal displacements
0
16
32
48
64
80
96
112
128
144
160
0 20 40 60 80 100 120 140 160 180
Diagrid 42° Diagrid 60° OutriggerDiagrid 75° SLS limit
U1 (m)
Z (
m)
Out
rigge
r
Dia
grid
42°
Dia
grid
60°
Dia
grid
75°
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsULS - load combinations, pushover
Out
rigge
r
Dia
grid
42°
Dia
grid
60°
Dia
grid
75°
Acronym Description Color
Outrigger Outrigger Structure
Diagrid 42°
Diagrid Structure with inclination of diagonal members of
42°
Diagrid 60°
Diagrid Structure with inclination of diagonal members of
60°
Diagrid 75°
Diagrid Structure with inclination of diagonal members of
75°
ULS Dead Gk Tamp Qk Qn W+X W-X W+Y W-Y
DEAD 1 - - - - - - - -
VERT 1 1 1 - - - - - -
+STATIC PUSHOVER FORCES
PUSHOVER
DEAD VERT
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 15
Numerical resultsDiagrid 60°: Pushover (YZ Sections)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
20000
40000
60000
80000
100000
120000
140000
160000
180000Pushover
Step25
Step28
Step37
Step44
Step51
Step67
U1 (m)
F (
kN)
Step 67Step 51Step 44Step 37Step 25
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsDiagrid 60°: Pushover+Vert (YZ Sections)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
20000
40000
60000
80000
100000
120000
140000
160000
180000
Pushover+Vert
Step11
Step16
Step39
Step47
Step55
U1 (m)
F (
kN)
Step 47 Step 55Step 39Step 11
VERT
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsComparison of capacity curves
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
20000
40000
60000
80000
100000
120000
140000
160000
180000
Pushover
U1 (m)
F (
kN)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Pushover+Vert
Outrigger
Diagrid 42°
Diagrid 60°
Diagrid 75°
U1 (m)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Pushover+Dead
U1 (m)
DEAD VERT
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 18
Numerical resultsDefinition of significant properties
R=Fmax (Strength)
K=Fy/Dy
(Stiffness)
m=Dmax/Dy (Ductility)
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 19
Numerical resultsComparison of significant properties
Outrigger Diagrid 42° Diagrid 60° Diagrid 75°
Pushover+Vert Pushover+Vert Pushover+Vert Pushover+Vert
Strength(R) – kN 94775 110185 104972 97131
Stiffness(K) – kN/m 77143 80615 71306 60897
Ductility(m) 1,535 3,587 5,681 2,564
Weight(P) - Ton 8052 6523 5931 5389
Weighted average (W.A.) of significant properties
Outrigger Diagrid 42° Diagrid 60° Diagrid 75°
Pushover+Vert Pushover+Vert Pushover+Vert Pushover+Vert
Strength(R) – kN 94775 110185 104972 97131
Stiffness(K) – kN/m 77143 80615 71306 60897
Ductility(m) 1,535 3,587 5,681 2,564
Weight(P) - Ton 8052 6523 5931 5389
W.A. 4,20 5,97 7,25 5,08
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsComparison of Mechanical Properties
R/R0
K/K0
m/m0
1,2 ((P0-P)/P0+1) 0
2
4
Pushover+Vert
Outrigger Diagrid 42° Diagrid 60° Diagrid 75°
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Preliminary robustness checksElimination of diagonal elements on Diagrid 60°
D1,L1
D1,L2
D2,L1
D2,L2
D3,L1
D3,L2
0 0.5 1 1.5 2 2.5 30
20000
40000
60000
80000
100000
120000
140000
Pushover
D1,L1D1,L2D2,L1D2,L2D3,L1D3,L2INTATTA
U1 (m)
F (
kN
)
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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DiagridOngoing research – apply simplified robustness indexes (1)
Kun λiun
Eigenvalues
Kdam λidam
Consequence factor
Robustness index
Nafday, A.M. (2011), “Consequence-based structural design approach for black swan events”, Structural Safety, Vol. 33, No. (1), pp. 108-114.
Olmati, P., Gkoumas, K., Brando, F. and Cao, L., (2013). Consequence-based robustness assessment of a steel truss bridge. Steel and Composite Structures, Vol. (14), No (4), pp. 379-395.
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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DiagridOngoing research – apply simplified robustness indexes (2)
d1d2d3
d4d5
d7
d6
37
5942 45
35 3823
63
4158 55
65 6277
0
20
40
60
80
100
1 2 3 4 5 6 7
Rob
ustn
ess
%
ScenarioCf max Robustness
83 87 88
5360
86
64
17 13 12
4740
14
36
0
20
40
60
80
100
1 2 3 4 5 6 7
Rob
ustn
ess
%
ScenarioCf max Robustness
Damage scenario Damage scenariod1 d2 d3 d4 d5 d6 d7 d1 d2 d3 d4 d5 d6 d7
Pier 6Pier 7
North
Pier 6
Thank [email protected]
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Numerical resultsCOMB 5 U.L.S.
DIAGRID 42°
DIAGRID 60°
DIAGRID 75°
Diagrid 42° Interior Columns
3%
97%
Shear
Interior Columns
Diagrid
11%
89%
Normal
Interior Columns
Diagrid
2%
97%
1%
ShearInterior ColumnsDiagrid/ Edge Col-umnsCorner Columns
11%
45%
44%
NormalInterior ColumnsDiagrid/ Edge Col-umnsCorner Columns
5%
95%
Shear
Interior Columns
Diagrid
7%
93%
Normal
Interior Columns
Diagrid
Diagrid 60°
Diagrid 75°
Interior Columns
Interior Columns
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Additional slides - DiagridMaterials
S275 (UNI EN 10025-2)
Modulus of Elasticity E 210000 N/mm2
Poisson’s Ratio n 0,3
Yield Strength fyk275 N/mm2
Tensile Strength fyk430 N/mm2
S460N/NL (UNI EN 10025-3)
Modulus of Elasticity E 210000 N/mm2
Poisson’s Ratio n 0,3
Yield Strength fyk430 N/mm2
Tensile Strength fyk540 N/mm2
S275 used for all profiles of outrigger
structure and for the interior structure of
diagrid buildings
S460N/NL with better mechanical
properties, is used for perimeter structure
of diagrid buildings
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 27
Additional slides - DiagridOutrigger structure
a – sections XZ (a1-Y=0m; a2-Y=9,5m; a3-Y=19,5m)b – sections XZ (b1-X=0m; b2-X=4m; b3-X=13,5m)
a1 a2 a3 b1 b2 b3
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Additional slides - DiagridOutrigger structure - beams
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Additional slides - DiagridOutrigger structure – columns
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
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Additional slides - DiagridWind load
Z(m)
q(kN/m2)
We,l
(kN/m2)We,u
(kN/m2)Z
(m)q
(kN/m2)We,l
(kN/m2)We,u
(kN/m2)
0 0,94 0,787 -0,972 80 1,95 1,639 -0,972
4 0,94 0,787 -0,972 84 1,98 1,66 -0,972
8 0,94 0,787 -0,972 88 2,00 1,68 -0,972
12 1,09 0,919 -0,972 92 2,02 1,699 -0,972
16 1,21 1,018 -0,972 96 2,04 1,718 -0,972
20 1,31 1,097 -0,972 100 2,07 1,735 -0,972
24 1,38 1,163 -0,972 104 2,09 1,752 -0,972
28 1,45 1,22 -0,972 108 2,11 1,769 -0,972
32 1,51 1,271 -0,972 112 2,12 1,785 -0,972
36 1,57 1,316 -0,972 116 2,14 1,8 -0,972
40 1,62 1,357 -0,972 120 2,16 1,815 -0,972
44 1,66 1,394 -0,972 124 2,18 1,83 -0,972
48 1,70 1,429 -0,972 128 2,20 1,844 -0,972
52 1,74 1,461 -0,972 132 2,21 1,858 -0,972
56 1,78 1,491 -0,972 136 2,23 1,871 -0,972
60 1,81 1,52 -0,972 140 2,24 1,884 -0,972
64 1,84 1,546 -0,972 144 2,26 1,897 -0,972
68 1,87 1,571 -0,972 148 2,27 1,909 -0,972
72 1,90 1,595 -0,972 152 2,29 1,921 -0,972
76 1,93 1,618 -0,972 156 2,30 1,933 -0,972
80 1,95 1,639 -0,972 160 2,31 1,944 -0,972
-1.5 -1 -0.5 0 0.5 1 1.5 2 2.50
20
40
60
80
100
120
140
160
We
We,u
We,l
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 31
Additional slides - DiagridSAP 2000 plastic hinges
Axial hinges, used for all elements of the outrigger structures and the perimetral system in the diagrid structures, and, bending hinges for the internal columns in the diagrid structures.For the axial hinges the constitutive equation is rigid and perfectly plastic, with a yield stress equal to fyk (430 MPa for diagrid structures and 275 MPa for the outrigger structure) and an ultimate deformation (eu) of 5%. These hinges are placed in the middle of the elements, with a relative length of 1, i.e. the hinges extend for the entire length.
Konstantinos Gkoumas03/10/2014
Structural behavior and robustness assessment of tall buildings: the case of diagrid systems
Page 32
Additional slides - DiagridSAP 2000 plastic hinges
For the bending hinges the behavior is defined starting from a moment-curvature diagram with a rigid and hardening-plastic constitutive equation, extrapolated using FEMA356.