Question

Economical depth of plate girder concept is based on

Answer 1

In a plate girder bridge, the plate girders are typically I-beams made up from separate structural steel plates (rather than rolled as a single cross-section), which are welded or, in older bridges, bolted or riveted together to form the vertical web and horizontal flanges of the beam. In some cases, the plate girders may be formed in a Z-shape rather than I-shape. The first tubular wrought iron plate girder bridge was built in 1846-47 by James Millholland for the Baltimore and Ohio Railroad.[2]

Plate girder bridges are suitable for short to medium spans and may support railroads, highways, or other traffic. Plate girders are usually prefabricated and the length limit is frequently set by the mode of transportation used to move the girder from the bridge shop to the bridge site.[3]

Answer 2

Economical Plate Girder

Explanation:

• In a plate girder bridge, the plate girders are commonly I-beams made up from isolated basic steel plates (as opposed to moved as a solitary cross-segment), which are welded or, in more seasoned extensions, blasted or riveted together to shape the vertical web and  horizontal flanges of the bar
• A plate girder is a developed I-bar segment, used to convey substantial burdens which can't be conveyed financially by moved I-areas. It is made by riveting or welding the steel plates in I-beam shape