Pile Foundation

 

Pile Foundation :-

 The use of pile as a foundation can be traced since olden times. The Art of driving piles under the  soil was stablished in Roman times. Now  a days, pile foundation is much more common than any other type of deep foundation.

A pile may be defined as " A long slender  structural member (relatively small diameter made up of timber, concrete or steel or composite materials driven or  installed into  the  weak ground to support the weak ground to support the structure through suitable  mean". Piles are usually driven in clusters or groups to provide foundations for structures. They may be subjected to vertical loads or  lateral loads or a combination of vertical and lateral  loads.

 

NECESSITY OF PILE FOUNDATION :-

Pile foundation is the most common type of deep foundation used to transfer the loads of the superstructures to a deeper strata. Pile foundations are used in the following conditions :

 

1.  Pile foundation is required when the soil at or just below the ground level is very weak i.e compressible and is unable to support the load transmitted by the structure.

2. A pile foundations is required when sub soil is subjected to non uniform settlement due to large variation in the load pattern i.e. it reduces differential settlement.

3. Pile  foundation is also  used to resist horizontal forces in addition to support  the  vertical loads in earth retaining structures subjected to horizontal wind pressure and seismic forces.

4. Pile are used support the foundations of important structures like transmission towers, off shore platforms etc. which are subjected to uplift forces or overturning moments.

5. Piles are used to transfer the load below the active zone in case of highly expensive soils in case of black cotton soil, which swell or shrink as the water content changes.

6. To carry the foundation deeper than the depth of scour for providing safety in the event the soil is erode away due to  scouring action.

7. Pile foundations are also used to support the foundations of structures constructed under water by transmitting the structural loads through deep water to  a strata.

8. Pile are sometimes used to compact soil deposits in loosegranular soil  to increase the load bearing capacity of the soil.

9. Piles are also used to protect water front structures against impact from ships or other floating objects.

10. Piles are also used to provide anchorage against horizontal pull from  sheet piling walls.