Housing the Spectacle: Glossary

Astroturf

An artificial grass surface. First developed for use in the Houston Astrodome after the dome's natural lawn deteriorated.
From the Daily Telegraph, April 21, 1966:
"Houston had spent $11 million building its mammoth, air-conditioned Astrodome... Now..[they are] spending $180,000 on a carpet of synthetic turf, called..Astroturf."

ASTM Standards

Performance or chemical standards for industrial materials and components set by the American Society of Testing and Materials (ASTM).

crane boom

The outermost arm of a crane. During the construction of the Astrodome special cranes with boom lengths up to 275 ft were used to lift truss sections to the roof's 210 ft high peak.

cable dome

A shorthand phrase most commonly used to describe tensegrity domes.

cantilever

A beam, girder, truss, floor or roof section unsupported at one end. Diving boards are cantilevers.

compression

A force or stress charactorized by pressure or squeezing.

compression ring

section through the U. S. Pavilion's compression ring.

A structural ring that acts in compression. Compression rings in pneumatic and tensegrity domes are located at the roof perimeter and anchor the roof cables.

berm

A mound of earth. The U.S. Pavilion's roof rested on an earth berm.

strain gauges

Instruments used to measure deformations and stresses of structures.

ellipse

A curve for which the sum of the distances from each point on the curve to two fixed points is equal

super ellipse

Ellipses with an exponent greater than 2.0. In the limit, as the exponent goes to infinity, the corners of a super ellipse become square.

erection tower

Towers used for the tempory support of elevated structural elements.

fabric skirts

Detail of fabric/cable connection at the U.S. Pavilion

Fabric strips used at the U.S. Pavilion to connect roof cables to fabric panels above.

Fuller, Buckminster

American inventor of the geodesic dome and the tensegrity dome, among other things.

funicular shape

The shape that a cable or tension structure takes under the action of particular loads.

geodetic

The shortest possible line be drawn from one point of a surface to another, its plane of curvature is everywhere perpendicular to the surface. Such a curve is called a Geodetic line.

from the New York Times Literary SupplementNovember 6, 1959 p.5:
With his geodetic domes and his synergetic geometry.. [Buckminster Fuller] is designing..methods of enclosing space that others may one day make into an architecture.

geodesic dome

a dome built according to the principles of geodetic construction patented by R. Buckminster Fuller
from the New York Times, March 20, 1959:
The geodesic dome combines the structural advantages of the sphere (which encloses the most space within the least surface, and is strongest against internal pressure) with those of the tetrahedron (which encloses least space with most surface and has the greatest stiffness against external pressure).

Geiger, David

Inventor of the cable-stiffened pneumatic dome, and the first builder of a long-span tensegrity dome (at the 1988 Seoul Olympics).

IBM-1130

The computer used to do engineering calculations for the U.S. Pavilion's fabric roof.

lamella dome*

A dome consisting of a series of intersecting skewed arches made up of relatively short members called "lamellas", fastened together at an angle so that each is intersected by two similar adjacent members at its midpoint, thus forming an interlocking diamond-patterned network.

laminar flow

Smooth and regular fluid flow -- the direction of motion at any point remaining constant as if the fluid were moving in a series of layers sliding over one another without mixing.

lateral loading

Loads acting horizontally -- wind or earthquake loads.

membrane

a thin pliable sheet-like tissue. Pneumatic domes and tensegrity domes use fabric to form their roof surfaces.

pile

A long, thin element, such as a steel pipe or a w-shape, which is driven into to ground and used in combination with other piles as a building foundation.

pneumatic dome

An inflated dome supported by internal air pressure.

post-tensioned*

Embedding within concrete members high strength steel cables (tendons), which are placed within cables and tensioned after the concrete has hardened, causing compressive forces within the concrete. By so placing and tensioning the tendons, the resulting compressive forces can be so applied as to induce a bending opposite to that caused by the applied load, thereby requiring less concrete.

prefabricate

To manufacture sections of a structure in a factory or yard prior to their assembly on a site, especially when the components are large or complex.

prestressed

Tension applied to an object during manufacture or prior to some other treatment, usually in order to counteract applied loads (as in prestressed concrete).

purlin*

A horizontal roof member spanning between beams and trusses, and to which the roofing material is attached.

PVC

polyvinyl chloride, commonly used for plumbing drain pipes.

space truss*

A three-dimensional framework used to span a rectangular area whereby the individual members are so interconnected that a truss effect is achieved to carry imposed loads to all four support sides.

statically determinate*

Any structure whose reactions and forces can be determined by the following: the summation of all vertical and horizontal forces acting on the member or framework must be equal to zero, and the rotation causing moment aboutany point must be equal to zero.

stratified

disposed in layers. Placed in alternate layers with something else.

tensegrity structure

A three-dimensional structure consisting of members under tension that are contiguous and members under compression that are not contiguous.
From R. B. Fuller: Ideas & Integrities, 1963, p. 170:
Geodesic Tensegrity (my name for the discontinuous-compression, continuous-tension structures) the ability to assemble unprecedentedly large, clear-span structures.

tension

A force or stress causing stretching. A constrained condition of the particles of a body when subjected to forces acting in opposite directions away from each other usually along the body's greatest length, thus tending to draw them apart.

u-factor*

Also called U-value or coefficient of heat transmission, it is a measure of the insulating value of building materials, expressed in B.T.U.'s per hour per square foot per degree Fahrenheit temperature difference between each side. The lower the u-factor, the better the insulation.

velocity

The speed and direction describing a moving object's travel.

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