This work is intended to assemble, in the light of a qualitative approach, what is already known about the changes over time in the bearing capacity of piles, setup and relaxation. The importance of such alterations is significant. After the installation process, the piles may keep their initial loading capacity, set it up by increasing it from a non-predictable percentage (which may eventually quadruple) or relax, losing most of its resistance (up to over percent). The cost of such phenomena justifies per se the need of an improved comprehension of such processes, and in the present work, a first step of a broader research project, the results and observations on the subject were collected and assembled. Representative cases found in the literature which contemplate variety in soil behaviour due to the driving of piles were selected and transcribed. Experimental evaluations where a growth or reduction in the bearing capacity of driven piles over time, eg. set-up and relaxation, were given priority. It was not the concern of this work to restrict the set-up and relaxation processes to more recent research because the initial intuitions, though not in charge of the present technological development, were not so distant from the proposals and models which followed. We thus deem as essential to foundation engineering a further insight into the subject, which will permit better and safer anticipations of the behaviour of driven piles over time, in view of the risks and economic losses which may arise from its absence. It is hoped that the present dicussion, by contributing to further a qualitative global view of the matter, may give rise to the adoption of scientifically ethical practices. To such, it is recommended that the information on such phenomena be made public.