twenty eight shells & structural systems ELEMENTS OF ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN DR. ANNE NICHOLS SPRING 2016 lecture

Transcription

1 ELEMENTS OF ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN DR. ANNE NICHOLS SPRING 2016 lecture twenty eight shells & structural systems Shells & Systems 1

2 Office Hours not available at this time link to posted schedule Shells & Systems 2

3 Arch & Shell Systems curved, thin surface or 2D structures see very little bending stresses design for axial stresses shear stresses efficient because of uniformly distributed loads Millennium Bridge in Newcastle, UK Shells & Systems 3

4 Arches behavior stabilization resist thrust compression only Shells & Systems 4

5 Shell Types shape classifications developable: revolution (vault) synclastic doubly curved same direction anticlastic: doubly curved opposite curvature free form Shells & Systems 5

6 Vaults wide arch nisee.berkeley.edu/godden Shells & Systems 6

7 Vaulted Shells can resist tension shape adds depth Shells & Systems 7

8 Kimball Museum, Kahn 1972 Shells & Systems 8

9 Kimball Museum, Kahn 1972 outer shell edges Shells & Systems 9

10 Kimball Museum, Kahn 1972 skylights at peak Shells & Systems 10

11 Domes arch of revolution compression some tension Shells & Systems 11

12 Domes stresses and displacements Harvard GSD Shells & Systems 12

13 Annunciation Greek Orthodox Church Wright, 1956 Shells & Systems 13

14 Annunciation Greek Orthodox Church Wright, 1956 Shells & Systems 14

15 Anticlastic Shells saddle or ruled shapes surface generated with straight lines tension follows cable drape compression follows arch Shells & Systems 15

16 Zarzuela Hippodrome, Torroja Shells & Systems 16

17 Zarzuela Hippodrome, Torroja 1935 Shells & Systems 17

18 Folded Plates increased stiffness with folding Shells & Systems 18

19 State Farm Center, Harrison & Abramovitz State Farm Center (Assembly Hall), University of Illinois Harrison & Abramovitz 1963 Edge-supported dome spanning 400 feet wound with 614 miles of one-fifth inch steel wire Shells & Systems 19

20 Systems total of components behavior of whole classifications one-way two-way tubes braced unbraced Shells & Systems 20

21 One-Way Systems horizontal vs. vertical Shells & Systems 21

22 Two-Way Systems spanning system less obvious horizontal plates slabs space frames vertical columns walls Shells & Systems 22

23 System Selection evaluation of alternatives Shells & Systems 23

24 System Selection Shells & Systems 24

25 Structural Design Criteria components stay together structure acts as whole to be stable resist sliding resist overturning resist twisting and distortion internal stability interconnectedness strength & stiffness Shells & Systems 25

26 Structural Design Sequences first-order design structural type and organization design intent contextual or programmatic second-order structural strategies material choice structural systems third-order member shaping & sizing Shells & Systems 26

27 Design Issues lateral stability all directions Shells & Systems 27

28 Design Issues configuration Shells & Systems 28

29 Design Issues vertical load resistance walls columns Shells & Systems 29

30 Design Issues lateral load resistance Shells & Systems 30

31 Design Issues lateral load resistance Shells & Systems 31

32 Design Issues multi-story cores, tubes, braced frames Shells & Systems 32

33 Design Issues multi-story avoid discontinuities vertically horizontally Shells & Systems 33

34 Final Exam Material my list: equilibrium - F & M supports, trusses, cables, beams, pinned frames, rigid frames materials strain & stress (E), temperature, constraints beams distributed loads, tributary width, V&M, stresses, design, section properties (I & S), pitch, deflection Shells & Systems 34

35 Final Exam Material my list (continued): columns Shells & Systems 35 stresses, design, section properties (I & r) frames P, V & M, P-, effective length with joint stiffness, connection design, tension member design foundations types sizing & structural design overturning and sliding

36 Final Exam Material my list (continued): systems levels design considerations design specifics steel (ASD & LRFD) concrete wood masonry Shells & Systems 36