Foundation is the lower most part of the structure which transmit the load of super structure to sub-soil without exceeding the bearing capacity of the soil. Foundation is also known as sub-structure. Foundation are generally provided to transfer the dead load or improved load, snow load, wind load, earth quack, etc. to supporting the sub-soil. It is an element of a structure which connects it to the ground and transfer loads from the structure to the ground.
The functions of foundation are,
- The soil does not fail under the action of load.
- The settlement of the structure should be permissible limit without causing crack in sub-structure.
Necessity of function of Foundation:
- Foundation should be taken sufficient deep to the ground of the building against the damage due to settlement.
- Foundation should be located that is performed may be defected that should be defected due top unexpected future changes.
- Reduction of load intensity.
- Foundation distribute a load to a large area so that intensity of load is based does not exceed the same bearing capacity.
Read Also: Introduction of Building Construction
Types of Foundation:
There are different types of foundation are as follows,
Shallow Foundation are those foundation which are provided at consideration depth below ground level. Such type of foundation is generally provided in area where hard strata considerable the depth of the foundation kept equal to or less than its width. The shallow foundations are classified as,
Spread Footing: This are those footings which distribute the super imposed load from wall and column over the large area the bore of footing is made up with thick layer plane concrete type of footing are provided when heavy load is to provide to transfer load bearing capacity.
Combined Footing: When the heavy load of a super structure is required to be transfer over the large area such type of footing are provided below the two adjacent column carrying equal or unequal loaded. It classified as,
- Rectangular Footing.
- Trapezoidal Footing.
Matt or Raft Footing:
Such type of footings is provided when super structure or a heavy load is required to transfer over the composite area in such the care matt foundation is used. Then allowable pressure of soil is varying load, such type of foundation to be most economical this are provided reduce the settlement of a foundation.
When the foundation of two adjacent angle is connected with the help of beam such type of beam is known as strap and corresponding foundation. In such type of foundation, supporting two unequal and heavy load the scrap will act as transformation member which distribute unequal of column equally to the sub-soil.
Deep foundation is a type of foundation which is generally provided to transfer a load of super stricture to soil of load bearing deep foundation are generally provided in black cotton soil, sandy soil, in such soil the depth of foundation is more as compared to width is classified as,
- Pile Foundation
- Pear Foundation
- Cession or Catherdone
Pile foundation are provided where heavy load is required to transfer the sub-soil when hard strata is available in such case pile foundation is provided the load is taken to lower level by means of vertical member which is made up of vertical timber, steel, etc. Pile foundation adopted instead of mat foundation when bearing capacity of soil is very low it is classified as on the basis of its function.
Circular type of foundation has large diameter to support and transfer the load down to ground. It is found in location where the strata consist of decompose rock over the hard strata pear foundation has a depth of 16m such type of foundation are provided for bridge structure.
Cession and Catherdon:
It is a temporary structure. The term cession taken from French word casses meaning box. Cession has a box like structure which had round rectangle or any other shape which is same from the surface either land or water to same desire it is classified in three types,
- Box Cession
- Open Cession or Open Wall
- Pneumatic Cession