Parts of Bridge Construction (in Details)

A bridge has many substructures and superstructure parts. Different types of bridges have different procedures for erection as well as different components. Here, an example of simple reinforced concrete bridge components is illustrated.

Following are the parts of a reinforced concrete bridge.

Parts of Bridge Superstructure

• Deck slab with a wearing coat: Deck is the part on which vehicle moves. A wearing course of bitumen or asphalt is provided to ease for the vehicle.
• Railings: Railings are provided on both the side of bridge. It ensures safety of the vehicle and pedestrians to falling off the bridge.
• Footpath: A bridge may or may not have a footpath. Generally, the footpath is provided for pedestrians.
• Longitudinal Girders: In the case of RCC T beam and deck type bridge, the longitudinal girders are provided to resist the longitudinal bending moment.
• Transverse Girders: These are provided for the lateral stability of longitudinal girders.
• Approaches: These are used at bridge ends.

Parts of Bridge Substructure

• Pier and Pier Caps: Piers are part of substructure, which transfers the load of the superstructure and live load to the foundation.
  As per IRC: 78-2014, the piers are defined as intermediate supports of the deck (superstructure).
  Various types of piers are listed below.
  • Hammer head type pier
  • Trestle type pier
  • Solid type pier
  • Framed type pier
  • Cellular type pier
• Bearing Pads or Bridge Bearings (also known as dampers): These are provided to allow for the longitudinal movement of girders. Bearing pads also accommodate movements because of seismic activities, and thermal expansions, and contractions.
• Abutments: Abutments are provided at the ends of bridges. They support the earth behind them. There are two types of abutments, namely Box Type abutments and Return Wall Type Abutments. 
• Foundation: Like any other civil engineering structure, the foundation is the bottommost part of any bridge. The foundation transfers all the kinds of loads of the bridge directly to the soil beneath. Following are the various kinds of foundations of bridges.
  • Pile Foundations
  • Caissons
    • Open well foundation
    • Pneumatic caissons

Criteria for design of the foundation of bridges are given in IRC 78-2014 (download IRC 78-2014)

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Standard Specifications And Code Of Rode Bridges IRC 5-2015

IRC: 6 – 2017 [Loads and Load Combinations] PDF Download

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