Pile foundation details
Pile foundations stand for deep foundations. They are built up with long, slender, columnar ingredients generally produced with steel or reinforced concrete and sometimes timber.
The prime objective of pile foundations is to transmit the loads from a superstructure, via weak, compressible strata or water onto powerful, more compact, less compressible and tough soil or rock at depth.
The piles are suitable for large structures as well as in circumstances where the underneath soil can’t resist extreme settlement.
Piles are effective for laying out the towers for high power transmission lines and in some situations are also utilized for supporting the multistory buildings.
Piles foundation depend on the following conditions :-
a. Type, size, and weight of the structure to be supported.
b. Physical properties of the soil at the construction site.
c. Depth to a stratum eligible to support the piles.
d. Potential for variations in the depth to a supporting stratum.
e. Availableness of materials for piles.
f. Number of necessary piles.
g. Scopes for driving piles.
h. Relative costs in place.
i. Necessary strength.
j. Types of structures close to the project.
k. Depth and type of water, if exist, over the ground into which the piles should be driven.
Pile Foundations are essential in the following conditions :-
1. Sub-soil water table is extremely high to easily impact the other foundations.
2. Load arising out of the structure is intense and uneven.
3. The construction cost of grillage or raft foundations is higher or their installation process is complicated because of local problems.
4. When it becomes complicated to retain foundation trenches in dry condition by pumping, because of massive inflow of seepage or capillary water.
5. When the process is difficult to timber the excavation trenches for deep strip foundation. (strip foundation-spread footing under wall ).
6. When overlay soil is compressible, and water-logged and firm hard bearing strata is situated at quite a large depth.
7. When structures are situated on river-bed or sea-shore and foundations tend to be scoured because of action of water.
8. Huge variations in sub-soil water level.
9. There are canal or deep drainage lines adjacent to the foundations.