Parts Of Bridge Construction (In Detail)

A bridge has several substructures and superstructure parts. Different types of bridges have different procedures of the 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.

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.
• Footpath: A bridge may or may not have a footpath. Generally, the footpath is provided for pedestrians.
• Longitudinal girders: Incase of RCC T beam and deck type bridge, the longitudinal girders are provided to resist the longitudinal bending moment.
• Transverse girder: These are provided for the lateral stability of longitudinal girders.
• Approaches: This are used at bridge ends.

Substructure

• Pier and pier caps – Piers are part of substructure which transfers load of superstructure and live load to the foundation.
  As per IRC:78-2014 the piers are defined as intermediate supports of 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): This are provided to allow longitudinal moments of girders.
• Abutments: Abutments are provided at the end of bridge. They support the earth behind them.
• Foundation: As like any other civil engineering structure foundation is the bottom most part of any bridge. Foundation transfers all the kind of load of the bridge directly to the beneath soil. Following are the various kind of foundation of bridge.
  • Pile foundation
  • Caissons
    • Open well foundation
    • Pneumatic caissons

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

You may also wish to read –

Types of Bridges as per different criteria
Standard Specifications And Code Of Rode Bridges IRC 5-2015
IRC:6-2017 [Loads and Load Combinations] PDF Download