“perceiving and conceiving” structures exo vs. endo - skeleton light and view...

“Perceiving and Conceiving” Structures

Exo vs. Endo - Skeleton

Light and view Penetrations……………………………………………..

Skin

Wrapping……………….Framing……………….Ordering

Movement

Light …………………………….. Heavy

Solid ….…………………………….. Void

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?

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

Structures in History• The development of structural materials and

structural theory has a long and varied history

“Ah, to build, to Build, that is the noblest of all the arts” – Henry Wadsworth Longfellow

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

•Corbelled stone dome •Mycenaean fortress

Corbelling is achieved by stacking masonry units in a stair-step fashion to bridge the opening.

Arches, Vaults, Domes

•Gravity shaped inverted arch •Arch Thrusts •St. Louis Arch

•Barrel Vault – an extruded arch •Dome – arch 360° •dome in bending

“An Arch never Sleeps” – James Fergusson

Load Bearing• Colosseum of Rome

• Hagia Sophia

Masonry load-Bearing 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.

Post and Beam

• Stone……………..

• Heavy Timber………………………………

• Reinforced Concrete……………………

• Steel…….

Post and Beam

The Hypostyle Hall results from the desire to make outdoor public open space …………………

The enclosure is independent

from the structure, either

by-pass continuous or infill …………………...…….

The Structure can meet the

Ground very delicately, on

Just a few points ……………………

Parthenon

Thomas hacker library

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 LoadsLoad 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 LoadsLoad 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

• Villa Savoye

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.

• Johnson Wax Building

Campus Buildings• Direct Load Bearing

• post and beam

• post and Platform•EMU – newer portion (west side)

•DEADY HALL

•Masonry load-bearing skin

•Arched window openings

•Lawrence Hall (concrete)

•Bookstore (concrete)

•Lillis Business School (steel)

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 MarbleThe 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.

Calatrava – Milwaukee Art MuseumThe 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?

Is Isolated Structure Architecture ?

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