“Perceiving and Conceiving”
Structures
Light …………………………….. Heavy
Solid ….…………………………….. Void
Skin
Beauty
Movement
Exo vs. Endo - Skeleton
Light and view Penetrations……………………………………………..
Wrapping……………….Framing……………….Ordering
Structures
• What role does the structural system play?
• Is the structure supportive or deterministic of the
aesthetic quality of the building? Or Is the Structural
system invisible?
• How has the role of the structure in a building changed
over time?
• What is my attitude about how to reveal or express
structure in my design?
Interrelated Architectural systems
• Structural Systems.............................. spanning and supporting
• Enclosure………………………………… defines perimeter and interior
• Apertures / Fenestration........... creates a Connection between
Interior and exterior spaces
• Spatial Ramifications………………………. structural organization
influences/creates space
• Materials……………………………. Structural and weather resistant
“Ah, to build, to Build, that is the noblest of all the arts” – Henry Wadsworth
Longfellow
Structures in History
• The
development of structural materials and
structural theory has a long and varied history
Structural Systems
• Direct
Load Bearing
•Bearing Walls
•Corbelling
•Arches, vaults, domes
• post
and beam
•Stone
•Heavy timber
•steel
•Reinforced concrete
• post and Platform
•Reinforced concrete
• others
Load Bearing
• Bearing Walls……
• Corbelling………………………
• Arches, Vaults, Domes…………………..
Bearing Walls
• Massive masonry walls carry compression loads
• The space is primarily vertical
• The skin is determined by structure……………….
• The problem is creating spans in masonry
•Span is limited by depth in stone lintels…………….
•Corbelling was an early solution
•The arch was the Roman solution to creating apertures and large
spans…………………………………..
Corbelling
Corbelling is achieved by stacking masonry units in a
stair-step fashion to bridge the opening.
•Corbelled stone dome
•Mycenaean fortress
“An Arch never Sleeps” – James Fergusson
Arches, Vaults, Domes
•Gravity shaped
inverted arch
•Barrel Vault – an
extruded arch
•Arch Thrusts
•Dome – arch 360°
•St. Louis Arch
•dome in bending
Load Bearing
Masonry loadBearing
structures were
solid and
monumental.
The challenge
was to create
light and airy
spaces. Notice
the proportion of
solid to empty
space in the
floor plans of the
colosseum in
rome and the
Hagia Sophia.
• Colosseum of Rome
• Hagia Sophia
Post and Beam
• Stone……………..
• Heavy Timber………………………………
• Steel…….
• Reinforced Concrete……………………
Post and Beam
The Hypostyle Hall results from
the desire to make outdoor public
open space …………………
Parthenon
The Structure can meet the
Ground very delicately, on
Just a few points ……………………
Thomas hacker library
The enclosure is independent
from the structure, either
by-pass continuous or infill …………………...…….
Bauhaus, dessau
Structural Forces
Two types of Forces:
1. Compression
2. Tension
•
Bending is the Result of Tension and Compression in a member
•
Tension and Compression can be broken up into Horizontal and
Vertical Components
•
Gravity loads and Lateral Loads result in tension and compression
of structural members
•
Gravity Loads: Dead loads (weight of structure) and live loads
(people, furniture, snow)
•
Lateral Loads: Earthquake, Wind, Earth retention
Gravity Loads
Load Distribution:
Gravity Load on Beam = P
Gravity Load on each Support = P/2
Two types of Forces:
1. Tension
2. Compression
•
Bottom of beam in Tension
•
Top of Beam in Compression
Reinforcing:
•
Steel reinforcing in concrete occurs
where beam is in tension because
concrete is weak in tension
Gravity Loads
Load Distribution:
Gravity Load on Beam = P
Gravity Load on each Support = P/2
Two types of Forces:
1. Tension
2. Compression
•
Bottom of beam in Tension
•
Top of Beam in Compression
Reinforcing:
•
Steel reinforcing in concrete occurs
where beam is in tension because
concrete is weak in tension
Lateral Loads
Moment Frame Deflection:
•
Exaggerated wind deflection
•
Occurs only if connections between
members are rigid (Welds)
Shear:
•
Connections are pinned (bolts, nails)
Two Solutions:
•
Make rigid connections
•
Diagonal X-Bracing / triangulation
Lateral Loads
Frame Deflection:
•
Exaggerated wind deflection
•
Occurs only if connections between
members are rigid (Welds)
Shear:
•
Connections are pinned (bolts, nails)
Two Solutions:
•
Make rigid connections
•
Diagonal X-Bracing / triangulation
Post and Platform
• Reinforced Concrete
Post and Platform
The Skin of the building is
independent of the structure,
which allows more fenestration,
and the space is primarily
horizontal except for the top
level.
• Villa Savoye
• Johnson Wax Building
Campus Buildings
• Direct
Load Bearing
•DEADY HALL
•Masonry load-bearing skin
•Arched window openings
• post
and beam
•Lawrence Hall (concrete)
•Bookstore (concrete)
•Lillis Business School (steel)
• post and Platform
•EMU – newer portion (west side)
Louis I. Kahn – Exeter Library, Exeter
•A Concrete Core provides Lateral Stability. . .
The atrium in the center lets light in from above, which
filters through the structure into the stacks on each
floor. Upon entering the atrium on the main floor, the
entire organization is understood in the clarity of the
spaces and structure.
Louis I. Kahn – National Assembly, Daka
•Bearing Walls of Concrete and Marble
The concrete Bearing walls are poured on site. Limited
by the building technology to 4’ pour heights, the
horizontal joint is expressed by bands of marble. Light
is brought in through openings in a layered wall system,
creating an inner street and innermost private space at
the “Heart.”
Calatrava - Oriente Station, Lisbon
•Steel and Concrete Soaring Structures
Continuous Spaces are Linked by Dynamic
Movement. Because of shifting boundaries as one
moves through the space, the structure defines
nodes and paths.
Calatrava - Oriente Station, Lisbon
•Steel Columns branch skyward
A tree-like Canopy provides shade and cover as
Branching columns are linked into a continuous
frame.
Is Isolated Structure Architecture ?
Calatrava – Milwaukee Art Museum
The structure of this canopy shades, and seems to
derive form from the wings of a bird… What is the
attitude about Structure? Is it sculpture ? Art?
Does it dominate or is it integral to the function of
the museum ?
How far should Structure reach to achieve beauty?
Structures
• What role does the structural system play?
• Is the structure supportive or deterministic of the
aesthetic quality of the building? Or Is the Structural
system invisible?
• How has the role of the structure in a building changed
over time?
• What is my attitude about how to reveal or express
structure in my design?
References
Pictures from:
• www.thomashacker.com
• www.uoregon.edu
• www.calatrava.com
•Mario Salvadori. Why Buildings Stand Up
Other good Sources:
• Ed
Allen. Architect’s Studio Companion
•Francis Ching. Building Construction Illustrated