 Wooden deck type | |
| Ancestor | Beam bridge |
|---|---|
| Related | Trestle bridge, truss bridge, moon bridge |
| Descendant | Leaf bascule, 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 supported by two or more plate girders . [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]
Generally, the depth of the girder is no less than 1⁄15 the span, and for a given load bearing capacity, a depth of around 1⁄12 the span minimizes the weight of the girder. Stresses on the flanges near the centre of the span are greater than near the end of the span, so the top and bottom flange plates are frequently reinforced in the middle portion of the span. Vertical stiffeners prevent the web plate from buckling under shear stresses. These are typically uniformly spaced along the girder with additional stiffeners over the supports and wherever the bridge supports concentrated loads. [4]
In the deck-type bridge, a wood, steel or reinforced concrete bridge deck is supported on top of two or more plate girders, and may act compositely with them. In the case of railroad bridges, the railroad ties themselves may form the bridge deck, or the deck may support ballast on which the track is laid. Additional beams may span across between the main girders, for example in the form of bridge known as ladder-deck construction. Also, further elements may be attached to provide cross-bracing and prevent the girders from buckling.
In the half-through bridge (also called a pony truss), the bridge deck is supported between two plate girders, often on top of the bottom flange. The overall bridge then has a 'U'-shape in cross-section. As cross-bracing cannot normally be added, vertical stiffeners on the girders are normally used to prevent buckling (technically described as 'U-frame behaviour' [5] ). This form of bridge is most often used on railroads as the construction depth (distance between the underside of the vehicle, and the underside of the bridge) is much less. This allows obstacles to be cleared with less change in height.
Multispan plate-girder bridges may be an economical way to span gaps longer than can be spanned by a single girder. Spacing of piers between the abutments is dependent on the capacity of the selected plate girders. Separate plate girder bridges span between each pair of abutments in order to allow for expansion joints between the spans. Concrete is commonly used for low piers, while steel trestle work may be used for high bridges.
A truss is an assembly of members such as beams, connected by nodes, that creates a rigid structure.
Beam bridges are the simplest structural forms for bridge spans supported by an abutment or pier at each end. No moments are transferred throughout the support, hence their structural type is known as simply supported.
A trestle bridge is a bridge composed of a number of short spans supported by closely spaced frames. A trestle is a rigid frame used as a support, historically a tripod used to support a stool or a pair of isosceles triangles joined at their apices by a plank or beam such as the support structure for a trestle table. Each supporting frame is a bent. A trestle differs from a viaduct in that viaducts have towers that support much longer spans and typically have a higher elevation.
An I-beam is any of various structural members with an I or H-shaped cross-section. Technical terms for similar items include H-beam, w-beam, universal beam (UB), rolled steel joist (RSJ), or double-T. I-beams are typically made of structural steel and serve a wide variety of construction uses.
A girder is a beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing flanges separated by a stabilizing web, but may also have a box shape, Z shape, or other forms. Girders are commonly used to build bridges.
A purlin is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin.
An orthotropic bridge or orthotropic deck is typically one whose fabricated deck consists of a structural steel deck plate stiffened either longitudinally with ribs or transversely, or in both directions. This allows the fabricated deck both to directly bear vehicular loads and to contribute to the bridge structure's overall load-bearing behaviour. The orthotropic deck may be integral with or supported on a grid of deck framing members, such as transverse floor beams and longitudinal girders. All these various choices for the stiffening elements, e.g., ribs, floor beams and main girders, can be interchanged, resulting in a great variety of orthotropic panels.
A girder bridge is a bridge that uses girders as the means of supporting its deck. The two most common types of modern steel girder bridges are plate and box.
A box girder or tubular girder is a girder that forms an enclosed tube with multiple walls, as opposed to an I- or H-beam. Originally constructed of wrought iron joined by riveting, they are now made of rolled or welded steel, aluminium extrusions or prestressed concrete.
The Victoria Bridge (Penrith), also known as the Victoria Bridge over the Nepean River, is a heritage-listed former railway bridge and now wrought iron box plate girder road bridge across the Nepean River on the Great Western Highway in the western Sydney suburb of Penrith in the City of Penrith local government area of New South Wales, Australia. The bridge was designed by John Whitton, the Engineer–in–Chief of New South Wales Government Railways, and built from 1862 to 1867 by William Piper, Peto Brassey and Betts (superstructure), William Watkins (piers). It is also known as Victoria Bridge, The Nepean Bridge and RTA Bridge No. 333. It was added to the New South Wales State Heritage Register on 27 May 2016.
A Howe truss is a truss bridge consisting of chords, verticals, and diagonals whose vertical members are in tension and whose diagonal members are in compression. The Howe truss was invented by William Howe in 1840, and was widely used as a bridge in the mid to late 1800s.
The Mabey Logistic Support Bridge is a portable pre-fabricated truss bridge, designed for use by military engineering units to upgrade routes for heavier traffic, replace civilian bridges damaged by enemy action or floods etc., replace assault and general support bridges and to provide a long span floating bridge capability. The bridge is a variant of the Mabey Compact 200 bridge, with alterations made to suit the military user as well as a ramp system to provide ground clearance to civilian and military vehicles.
La Vicaria Bridge is a through arch bridge that spans the Segura River, where it meets La Fuensanta Reservoir near Yeste, in the province of Albacete, Spain. It forms part of a future road that will join Yeste with Letur and the neighbouring area to the east. The bridge has 2 vehicle lanes and 2 sidewalks.
A steel plate shear wall (SPSW) consists of steel infill plates bounded by boundary elements.
A T-beam, used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a T-shaped cross section. The top of the T-shaped cross section serves as a flange or compression member in resisting compressive stresses. The web of the beam below the compression flange serves to resist shear stress. When used for highway bridges the beam incorporates reinforcing bars in the bottom of the beam to resist the tensile stresses which occur during bending.
The Hadley Parabolic Bridge, often referred to locally as the Hadley Bow Bridge, carries Corinth Road across the Sacandaga River in Hadley, New York, United States. It is an iron bridge dating from the late 19th century.
A balloon flange girder or (colloquially) balloon topper is a form of vertical I-beam wrought iron plate girder, where the top flange, instead of being a simple flat plate, is extended into a hollow tube. When a girder is subjected to a positive bending moment the top flange acts in compression making a flat plate flange more susceptible to local buckling than the balloon flange is.
The Longford Railway Bridge is a railway bridge spanning the South Esk River, in Longford, Tasmania. The Western Railway Line travels over the bridge, enabling freight movement to/from the major Container ports of Burnie and Devonport and the rest of the state. In 1978, it was listed in the now-defunct Register of the National Estate.
Burdekin River Rail Bridge is a heritage-listed former railway bridge on the Great Northern railway over the Burdekin River at Dotswood, Charters Towers Region, Queensland, Australia. It was designed by Henry Charles Stanley and built from c. 1896 to 1899 by Swanson Brothers. It is also known as Macrossan Bridge. It was added to the Queensland Heritage Register on 21 October 1992.
| Structural types |
|  |
|---|---|---|
| Lists of bridges by type | ||
| Lists of bridges by size | ||
| Additional lists | ||
| Related | ||
| Authority control databases: National |
|---|
