Arch Bridges Turner Crane Arch Bridges are the oldest type of bridges after the girder bridges. There are four basic types of arch bridges: –Hinge-less –Two-hinge –Three Hinge –Tied Arches Force is pushed out along the curve of the arch towards the abutments.

Hinge-less Bridge- Allows No Rotation at Foundations, Only Built at Very Sturdy Locations Because of Force Placed on the Foundations Two-Hinge Bridge- Forces generated at the hinged bearings, most commonly used type, generally the most economical Three Hinge- Contains an extra hinge at top of arch, suffers very little if movement in the foundations due to earthquakes, sinking, etc., Rarely used in recent times Tied Arches- used in places where the ground is not strong enough to support the horizontal forces, to alleviate the horizontal pressure the girder “ties” both ends of the arch together

Pont du Gard Built in 19 B.C. in Nimes, France Length- 273 meters Height- 49 meters Built to supplement Nimes water supply The arches were constructed of uncemented masonry Most of the aqueduct is built underground and has a slight drop of 1 in 3000 feet, by adding the drop they were able to use the natural gravitational flow and pressure systems were not needed. There are 6 arches in the lowest story, 11 in the second story and 36 in the top level.

URLs html PICTURES USED: –Bayonne Bridge, Bayonne Bridge, New Jersey –Tacony-Palmayra Bridge, Palmayra New Jersey –Pont du Gard –Francis Scott Key Bridge, Washington, D.C.