Relier Pairs BridgesVersion en ligne for architects and engineers par Pauline Borg 1 The simplest kind of bridge, with a straight beam crossing a gap. Because this kind of bridge is not particularly strong, a single beam cannot cross a wide gap. 2 span 3 suspension bridge 4 A structure that carries water from one place to another, usually elevated, traditionally built of stone. 5 Everything below the bridge roadway. This supports the superstructure. It transfers the load from the superstructure to the soil or rock below. Piers and abutments are part of this 6 Limitations or conditions that a design must satisfy. For example, a bridge might need to be at least a certain height, cost no more than a certain amount, and be safe in an earthquake that measures 7.0 on the Richter scale. 7 caisson 8 abutment A large chamber, watertight but open at the bottom, which is filled with compressed air and lowered into a body of water to allow construction work at the water’s bottom. beam bridge A type of bridge in which the bridge deck is hung from cables that are strung across a gap over towers. Vertical cables hang from these cables to support the bridge deck. The structure at each end of a bridge that supports the ends and resists the outward pressing forces of, for example, an arch bridge. It is often built of stone or concrete. aqueduct constraints substructure The part of a bridge or length of the bridge deck between supports.