SPIDERWEBS TO SKYSCRAPERS: The Science of Structures - Glossary
arch
A curved structure resting on upright supports that is used for bearing a load.
beam
A straight, flat piece of material supported at either end.
cantilever
An arm that sticks out from a central support and that can be used to bear a load.
cement
A gray, powdery substance made up of certain kind of ground-up rocks. When mixed with sand and water, it hardens to form concrete.
cofferdam
A water-tight enclosure, from which the water can be pumped, to give a dry foundation for bridges and piers.
concrete
A hardened mixture of cement, sand, and water which may also include small stones and steel rods for extra strength.
cupola dam
A dam that curves both from side to side and from top to bottom.
earth-sheltered building
A building that is partly or completely covered by soil.
foundation
A hard base, below ground level, upon which a building rests.
geodesic dome
A dome-shaped structure built from flat, interlocking panels of identical shape.
girder
A long beam, usually made of iron or steel, used for structural support.
gravity dam
A dam that is much wider at the bottom than at the top. It relies on its own weight, rather than a curved shape, to hold back the water.
piles
Columns of steel and concrete that are driven deep into the ground to provide a firm foundation for buildings such as skyscrapers.
prestressed concrete
Concrete containing steel rods that are held tightly stretched while the concrete is setting. This is the strongest type of concrete.
reinforced concrete
Concrete that has been strengthened inside with steel rods.
shaking table
A piece of equipment used by scientists to study how earthquakes might affect a building. It consists of a platform that can be loaded and vibrated in various ways.
steel
A metal made by mixing molten iron with a small amount of carbon. This makes it stronger than iron alone.
suspension bridge
A bridge whose weight is supported by steel cables slung over the top of tall metal piers.
truss
A framework of wood or iron, usually in the form of interlocking triangles, that provides support.
