The estimation of pile load capacity and settlement under a load is based on the results of field investigations, laboratory testing and the empirical and semi-empirical methods. These estimated values should then be confirmed by field pile load tests. Pile load tests, in practice, are normally executed in two alternative ways:
1. Test Pile Preliminary pile design is first carried out on the basis of site investigations, laboratory soil testing, and office study. Pile load tests are then carried out to refine and finalize the design. For these conditions, the test piles are generally tested to failure.
2. Test on a Working Pile In areas where previous experience is available, pile design is carried out based on the site investigations, laboratory soil testing, and office study. Pile load tests are then carried out on randomly selected actual piles to check the pile design capacities. In these situations, the piles are generally tested to two times the design capacity.
The equipment and test procedures for these two alternatives are essentially similar. The main difference is the level of final loading. Therefore, the details of tests presented below are applicable for both of the tests listed above. The pile load tests include axial compression, pullout, and lateral and dynamic loads.