Is a PDA test required during the test pile period to establish driving criteria, as well as during the production pile period?
PDA testing establishes driving criteria. It should include testing piles either as part of a preconstruction test program or, at minimum, the first piles driven on a project. The testing should cover the footprint of the site to investigate its variability. With larger projects, any pile with an unusual driving log should be tested. Periodically, an engineer should test these piles to confirm consistent hammer performance. This is because hammer performance affects the blow count, which is the basis for most driving criteria.