Plate girder bridge
From Wikipedia, the free encyclopedia
| Plate Girder Bridge | |
|---|---|
| |
| Below roadbed type | |
| Ancestor | Beam bridge |
| Related | Trestle, truss bridge, moon bridge |
| Descendant | Tubular bridge |
| Carries | Pedestrians, automobiles, trucks, light rail, heavy rail |
| Span range | Short |
| Material | Iron, steel |
| Movable | No |
| Design effort | low |
| Falsework required | No |
A plate girder bridge is a bridge often supporting railroad roadbeds over short spans. This bridge may be a shallow U-shape in cross section with the roadbed at the bottom of the U or the bridge may be entirely under the roadbed. Each side consists of deep steel plate shear members with a strong top and bottom chord, forming what is called an I beam. The top chord is stressed under compression, the bottom under tension. Additional light members are attached to the shear members between the top and bottom chord to add stiffness to the plate to prevent buckling.
For the under roadbed type the two members of the bridge will be connected at the bottom with additional light truss elements and at the top with decking to form a box structure.
[edit] See also
- Beam bridge - the ancestor of the plate girder bridge
- Box girder bridge - an evolution of the plate girder bridge
- Trestle, some modern steel trestles are composed of a number of girder bridge segments.
