Nasra Gahousson Nimaga ARC 560 | POLITICS OF THE ENVELOPE| Instructor: Alejandro Zaera Polo | FALL 2011
Structure & infill
THE DIAGRID
PROJECT DESCRIPTION Diagrids, or exodiagonal systems, are perimeter structural configurations characterized by grid of diagonal members which are involved both in gravity and in lateral load resistance.1 Unlike conventional orthogonal structures for tall buildings (ex. framed tubes and the like), the diagrid has the ability to carry lateral wind loads much more efficiently. Also, the diagrid offers column free floor plates and removes the necessity to have a heavy concrete core that deals with gravity loads. It thus offers complexity and perhaps one can argue that the diagrid is (at times) used for the point of rhetoric and its use is rooted in architectural ingenuity and the realization that structure can be expressed beautiful while at the same time allowing for more complex forms. Diagrids are becoming more and more widespread especially in formally complex high rises and wide span buildings. However, this project is less focused on Diagrids' structural efficiency and their ability to efficiently resist lateral shear by axial forces and more interested in how their diffusion of verticality gives rise to new and interesting relationships between the structure/ diagrid members and the glazing or spaces in between them. It is therefore, an analysis of the structure and infill of diagrids vis à vis four noteworthy examples namely; Swiss Re and Hearst Tower by Norman Foster + Partners, the CCTV headquarters by OMA and the Beijing Olympic stadium by Herzog and de Meuron. 1 Torano, Maurizio, Raffaele Arpino, Elena Mele, Giuseppe Brandonisio, and Antonello De Luca. "An Overview on Diagrid Structures for Tall Buildings." Dipartimento di Ingegneria Strutturale. Universita degli Studi di Napoli Federico II, n.d. Web. 19 Dec. 2011. <www.dist.unina.it/proc/2011/SEWC11/S
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2
SWISS RE HQ, 30 ST MARY AXE FOSTER+ PARTNERS. LONDON, UK, 1997-2004
Number of floors: 40 H in meters (to the top of the dome): 180 Height in meters to the highest occupiable floor: 168 Floor to floor height: 4.15 m Site area: 0.57 Ha/1.4acres Weight of Steel Used (tonnes): 8358 Weight of Diagrid members (tonnes): 2423 Unit Steel Weight kN/m2 : 1.12 Weight of diagrid unit: 0.32
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4
5
6
h = vertical height l = horizontal distance between nodes fp = number of floor plates that are intersected dy the diamond
=56°
=62°
16.60m
8.30m
d=8.3m h=8.3m l=9.0m
fp = 4
9.00m 7
8
HEARST TOWER
FOSTER+PARTNERS. NYC, USA, 2000-2006
Number of ďŹ&#x201A;oors 46 H in meters 183 Weight of Steel Used (tonnes) 10480 Weight of Diagrid members (tonnes) 3040 Unit Steel Weight kN/m2 1.32 Weight of dagrid unit 0.38
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10
11
12
h = vertical height l = horizontal distance between nodes fp = number of floor plates that are intersected by the diamond
=70°
=40°
33.0m
h=12.3m l= 16.5m
16.5m
fp = 8
12.3m
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14
CCTV
OMA. BEIJING, CHINA, 2002-DATE
Number of ďŹ&#x201A;oors: 9,14,44,54 H in meters Weight of Steel Used (tonnes) Weight of Diagrid members (tonnes) Unit Steel Weight kN/m2 Weight of diagrid unit Total Area (sqm): 405,057 Total Facade Area (sqm): 83,808 TotalGlass Area (sqm): 70,000 Total Volume (cubic meters): 950,200
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16
17
18 11.39m
3.52m
33.58m
16.36m
h = vertical height l = horizontal distance between nodes fp = number of floor plates that are intersected dy the diamond
h=varies l=varies =approx 75°
=approx 51°
fp = varies
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20
Beijing National Stadium
HERZOG & DE MEURON. BEIJING, CHINA, 2003-2008
H in meters (to the top of the dome): 69 Length in meters: N-S: 320 Width in meters: E-W: 297.3 Capacity: fixed seats 91,000; temporary seats 11,000Length of steel used: 26 km ( unwrapped steel used) Weight of Steel Used (tonnes): 42,000t Construction System: steel frame and fabric lining Construction area (sqm): 258,000 Number of Levels: 6 above ground, 2.5 below ground Site Area (ha): 20.29 Building Footprint: Plinth: approx. (sqm): 120’000 Building Footprint: Stadium vessel (sqm): 69’729
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23
24
25
26
69.00m
1
1 =81°
1 =94° fp = varies
1
1
1 =59°
2
1 =67° fp = varies
1
2
2
2
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