The results of numerous vibratory tests on model piles in clay are presented in this thesis with the purpose of studying the behavior of piles subjected to vibratory loadings. The effects of pile length, time after driving, soil consistency, dynamic force amplitude, and free water surrounding the pile were investigated. The effect of confining walls on such tests received special attention. Tests were also performed on two model pile groups. The possibility of representing a pile subjected to vibratory excitation by discrete masses and springs and the soil reaction by Kelvin models was studied, and an attempt was made to correlate theoretical results with model results. Finally, a very simplified approach was proposed for determining the maximum amplitude at the natural frequency for a pile subjected to vibratory loading.