Construction of bridge and its different parts
In bridge construction, all the primary materials are arranged within three areas foundation, substructure and superstructure.
Foundation – It retains the shallow or deep base of the bridge and transmits it’s load to the bearing strata that contains foundations under the main extent of the bridge and the abutments underneath starting points of the bridge.
Substructure – Main components are piers, abutments, spandrels, caps, bearings, and other components which sustain the topmost construction.
Superstructure - All the portions of the bridge which are affixed on top of the supporting substructure system, it covers components like decking, girders, slab, and everything provided over the main deck like posts, steel truss system, bridge girder, cable-stayed system, cable suspended systems and more.
Given below, the details on main constituents of modern bridges :-
Abutment – It stands for the endpoints of the bridge. In order to tolerate extreme lateral pressures, abutment is reinforced.
Pile – It is also called beam, footing, and pier. In pile system, reinforced concrete post is pushed into the ground to function as the leg or provide support for the bridge. The distance among the piles is measured to give support to the rest of the structure that will be placed on top of them.
Cap – Cap stands on top of the pile beam to give extra support as well as distribute the load to the piles underneath. The amalgamation of Pile and Cap elements is known as Bent.
Girder or Span – It refers to one of the prime constituents of the bridge that attaches all the Piles beams. It comprises of several simple spans, a single continuous span supported by various beams, cantilever spans and cantilever spans having the suspended span among them.
They are generally created with metal or reinforced concrete and also produced in the form of haunches girded to sustain extra load. Girder sections are created with truss network (or Orthotropic beams) to raise their resistance strength against load.
Girders are also applied as a part of rigid frame network where they are totally attached with frame legs (which can be slanted or remain in V shape).
Superstructure truss network – Truss network that provides support to travel surface, is built with three different ways like Deck truss where traffic passes on top of truss network, Pony truss where truss network passes among two parallel walls of trusses, and Through truss that provides extra cross-braced truss network over and beneath the traffic.
Deck beam – Simple continuous decks are created with metal or reinforced concrete. They comprise of sub-components like approach slab, expansion joint, drainage scupper, curb, running surface, footpath.
Barriers – Sides of the bridge decks normally contain extra barrier constituents like railings, handrails and ground fixtures.
Arch – Arches on the bridges are characterized with the number of hinges included (normally among zero or three) which find out how much stress and load they can securely bear, and the type of materials used for construction (solid material, truss system). Arches underneath the bridge are known as spandrel-braced (cantilever) or Trussed deck arch.
Spandrel – Spandrels belong to the almost triangular space among the primary pillar of the bridge and decking. Stone bridges employ filled “closed” spandrels deck arches, whereas modern bridges composed of metal use open spandrel deck arch configurations.
Truss – Framework is constructed by joining the triangles and other forms which distribute load and stress forces over its complete structure. They are generally classified into various categories like simple truss (King and Queen posts), covered bridge truss (multiple kingpost truss, Howe truss, long truss, Burr arch truss, town lattice truss, Haupt, Smith, Partridge and Child truss), Pratt truss (and it’s many variations), Whipple truss, Warren truss variations, Howe truss, Lenticular truss, Fink truss, multiple Cantilever truss variations, and suspension truss arches.