Pile foundations are one of the type of deep foundation. These foundations transfer load deeper to the hard strata much below the ground surface. But there are certain issues in the design of pile foundations related to selection of type of pile foundation and pile installation method.
The key design issues in relation to pile foundations include:
1. Selection of the type of pile and installation method;
2. Estimation of the pile size in order to satisfy the requirements of an adequate margin of safety against failure of both the supporting soil and the pile itself, both in compression and tension;
3. Estimation of the settlement of the foundation, and the differential settlement between adjacent foundations;
4. Consideration of the effects of any lateral loading, and the design of the piles to produce an adequate margin of safety against failure of the soil and the pile, and an acceptable lateral deflection;
5. Consideration of the effects of ground movements which may occur due to external causes (such as soil settlement and swelling), and the estimation of the movements and forces induced in the pile by such movements;
6. Evaluation of the performance of the pile from appropriate pile loading tests, and the interpretation of these tests to evaluate parameters which may be used to predict more accurately the performance of the pile foundation.
7. The selection of a pile foundation type for a structure should be based on the specific soil conditions as well as the foundation loading requirements and final performance criteria.
8. There are numerous types of foundation piles. A pile classification system may be based on type of material, installation technique and equipment used for installation.
9. Foundation piles can also be classified on the basis of their method of load transfer from the pile to the surrounding soil mass.