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Bridge Truss Designs
Describing Factors
The four main factors are used in describing a bridge. By combining these terms one may give a general description of most bridge types.
- span (simple, continuous, cantilever),
- material (stone, concrete, metal, etc.),
- placement of the travel surface in relation to the structure (deck, pony, through),
- form (beam, arch, truss, etc.).
The three basic types of spans are shown below. Any of these spans may be constructed using beams, girders or trusses. Arch bridges are either simple or continuous (hinged). A cantilever bridge may also include a suspended span.
Comon Travel Surfaces
Arch types
Simple Truss types
Pratt Truss types
Whipple Truss types
Warren Truss types
Other Truss types
Suspension types
The longest bridges in the world are suspension bridges or their cousins, the cable-stayed bridge. The deck is hung from suspenders of wire rope, eyebars or other materials. Materials for the other parts also vary: piers may be steel or masonry; the deck may be made of girders or trussed. A tied arch resists spreading (drift) at its bearings by using the deck as a tie piece.
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