Skip to main content

Short note: components of a bridge

Short answer

A bridge has a superstructure (deck slab, wearing coat, girders, cross girders, kerbs, footpaths, railings, expansion joints) and a substructure (piers, abutments, wing walls, foundations below scour depth). Bearings transmit loads and allow movement; approach slabs and protection works complete the bridge.

Write a short note on components of a bridge.

A bridge consists of a superstructure, which carries the traffic, and a substructure, which transfers the load to the ground.

Superstructure

  • Deck slab with wearing coat, carrying the traffic loads.
  • Main girders (RCC, PSC or steel) or a truss/arch, with cross girders for lateral load distribution.
  • Kerbs, footpaths, railings/parapets, expansion joints and drainage spouts.

Bearings between the superstructure and substructure transmit the reactions and permit rotation and thermal movement.

Substructure

  • Piers: intermediate supports with a pier cap.
  • Abutments: end supports that retain the approach fill; wing/return walls retain the earth.
  • Foundations: footings, piles, wells or caissons, taken below the scour depth.

Others: approach slab and embankment, guide bunds, apron and protection works. Loads and dimensions follow IRC:6, IRC:5 and the Nepal DoR bridge standards.

  Railing  Deck + girders     Railing
  ____________________________
 |Abutment|__Bearing__|Pier|Abutment|
  Wing wall  HFL ~~~~~~~  Wing wall
  Foundation below scour level

✓ Answer checked by Claude Opus 5.5 (high effort)

Related questions

All Transportation Engineering II chapter 5 questions →