The characteristics and history of beam girder bridges

For the longer span beams, beyond about50 m, they are practically the only feasible deck section. Reinforced Concrete T-Beams[ edit ] Concrete alone is brittle and thus overly subject to the shear stresses a T-beam faces where the web and flange meet.

Reinforced-concrete beam and girder bridges can be divided into two categories: standard and conventional Truss bridges were introduced very long ago, immediately becoming one of the most popular bridge types thanks to their incredible resilience and economic builds that require a very small amount of material for construction.

beam bridge diagram

T-beam, slab, through girder, and box culverts were constructed during this phase. Beam Bridges Beam bridges — employ the simplest of forms — one or several horizontal beams that can either simply span the area between abutments or relieve some of the pressure on structural piers.

The high form work costs caused a reduction in the number of cells fig f, g, h. During construction, bracing is needed to stabilise both the bottom flanges adjacent to intermediate supports and the top flanges in midspan regions.

The largest aqueducts are made of stone and can have multiple tiers of arched bridges created one on top of each other. As well, after the flood, a large number of beam and girder bridges were constructed.

While all bridges need to handle all those forces at all times, various types of bridges will dedicate more of their capacity to better handle specific types of forces.

How much weight can a beam bridge hold

The ability to customize a girder to the exact load conditions allows the bridge design to be more efficient. Design[ edit ] All bridges consist of two main parts: the substructure, and the superstructure. Falsework required No unless cast-in-place reinforced concrete is used Beam bridges, also known as stringer bridges, are the simplest structural forms for bridge spans supported by an abutment or pier at each end. Solid side rails with recessed panels were common on slab bridges. The bracing would need to be removed after casting because it would attract unwanted forces when the slab is subject to local loading above it and is thus not favoured by constructors. In most cases, the most effective bracing system is a triangulated frame between adjacent girders. In such cases, the bracing at supports has to be designed to transfer the collision loading down to the restrained bearings. In roadway applications it is usually a poured reinforced concrete slab, but can also be steel grid or wood plank. The stem or stub is the main body of the foundation. The main beams could be I-beams also known as H-beams , trusses , or box girders. It has high structural efficiency which minimizes the prestessing force required to resist a given bending moment, and its great Torsional strength with the capacity this gives to re-centre eccentric live loads, minimizing the prestress required to carry them.

Disadvantages: One of the main disadvantages of box decks is that they are difficult to cast in-situ due to the inaccessibility of the bottom slab and the need to extract the internal shutter. The fabricator receives large plates of steel in the desired thickness, then cuts the flanges and web from the plate in the desired length and shape.

But it is more efficient cross-section.

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Girder bridges|JFE Engineering Corporation