5 Component Parts Of A Bridge
The component parts of a bridge can be broadly categorized as follows:
- a) Superstructure
- b) Substructure
The upper part of a bridge consisting of a structural system in the form of beams, girders, arches, suspension cable & truss etc. is called superstructure. The function of the superstructure is to provide carriageway over which the traffic moves with safety.
The lower part of a bridge consisting of a structural system in the form of abutments, piers etc. along with their foundation, which supports the superstructure is called substructure. The function of the substructure is to support the superstructure. The substructure of a bridge consists of the following 5 components parts:
The portions of roadway or railway on both the ends of a bridge are known as approaches. It is provided to enable the vehicle running on roadway or railway at a normal level to approach the bridge floor level.
The end supports of bridge superstructure are called abutments. Abutments are provided to support the superstructure and to retain the earth pressure on their back.
3. Wing walls
The walls constructed on both sides of abutments to retain the earth of drainage bank and approaches, are called wing walls. Wing walls are provided to protect the drainage bank from erosion.
The intermediate supports of a bridge superstructure are known as piers. Piers are provided when the length of the bridge is more. The functions of piers are:
- To take and transfer the load from superstructure to the sub-soil through the foundation.
- To divide the length of the bridge into suitable number of spans.
The lower most part of the bridge substructure is called foundation. The function of the foundation is to transfer the load from superstructure to the sub-soil through the foundation.