Steel cage construction

• The art of sheltering people both
physically and spiritually from the raw
elements of the unaltered world
• Vertical
• Horizontal
Great Pyramids at Giza -2600 BCE
Post & Lintel
• Horizontal beams laid across open space
between vertical supports
• Limited by lack of tensile strength withstands bending
• Has compressive strength- withstands
• Columns- consist of a shaft, base, capital
• Fluting- may be carved vertical lines on
the shaft
• Base- may be none, stepped, or
elaborately stepped
• Capital- uppermost section, transition from
top of column to lintel
Greek Architectural Orders
• Doric Order- simple shaft, no base,
curved shape supporting a squared capital
• Ionic- shaft with fluting, rests on stepped
base, carved scrolls on capital called
• Corinthian- most complex, fluted column
rests on a detailed, stepped base with
carved, stylized acanthus leaves on the
Arch Construction
• Stresses transfer outward from center
(keystone) to legs: does not depend on
tensile strength of materials
• Round- Roman
• Horseshoe- Moorish
• Lance- pointed, Gothic
• Ogee arch
Arch types
Arch Construction
• Perfected by the Romans by 2nd c. BCE
• Can define large spaces because the
stress is transferred from the keystone to
the legs
• Keystone- wedge-shaped central stone in
the arch; it is inserted last & locks the
other stones in place
• Vault- arched masonry structure that
spans an interior space
Joined Arches
Arcade- a series arches placed side by side
Tunnel vault- half-round arch extended in
depth, arches placed back to back to enclose
Groin vault- formed by the intersection of two
barrel vaults of equal size at right angles
Ribbed vault- tunnel or groin vault in which
the lines marking the diagonal intersection of
the vaults are reinforced with raised masonry
Dome-arch rotated 360 degrees on its vertical
Arch Supports
• Buttress- reinforcement to the legs of an
arch to prevent them from caving outward
• Flying Buttress- buttress designed to
overcome bulk of stone by accomplishing
structural ends that were light in
Contemporary Structural Systems
• Cantilever- overhanging beam or floor
supported only at one end
• Bearing wall- the wall supports itself, the
walls and the roof
• Skeleton frame-a framework supports the
building, the walls attach to the frame
forming an exterior skin
• Skeleton frame
– 1. Balloon construction: When the framing
utilizes wood, as in house construction
– 2. Steel cage construction: When the metal
forms the frame, as in skyscrapers
Building Materials
• Stone- post & lintel; also combined with
mortar or brick & mortar, called masonry
• Concrete- pre-cast concrete (cast in place
using wooden forms around steel)
• Ferro-concrete (reinforced concrete)
• Wood- balloon framing or post & beam
• Steel: steel cage, cantilever
• Steel suspension (bridges, superdomes,
aerial walkways)
• Geodesic dome
Pre-cast Concrete
Steel Suspension
Common Terms
Line, forms, repetition
Materials, texture
Scale & proportion
Space: how do the forms (walls, ceiling,
stairs, entries, roof) enclose the space
Architectural Considerations
• Structural system
• Context- the environment. How does the
example relate to the physical environment –
in contrast to or reflective of surroundings
• Circulation: design and flow of contiguous
spaces relative to function
• Climate• Function- the purpose of the building
• Dynamics- stability, instability & movement
• Style- historical reference