Dynamic effects of the machines play a major role in sizing of the foundation where conditions, like resonance is avoided by varying the stiffness and the mass of the structure which leads to modifications in foundation sizes. In this paper, a piled machine foundation in sandy soil is analyzed. A detailed 3D finite element analysis approach is considered using finite element software (ANSYS v.11). Machine
foundations resting on end bearing piles are modeled. Harmonic dynamic load is chosen. A parametric study is carried out to investigate the effect of several parameters including: geometry of the piled machine foundation, the amplitude of the dynamic load, and frequency of the dynamic load.
It is concluded that as the pile cap thickness increases, the oscillation of displacement decreases due to geometrical damping of the pile cap. There is a limit of pile cap size at which its stiffness governs its dynamic response, above this size, the weight of the cap overrides its stiffness effect, and the additional weight by cap leads
to increase the foundation displacement. On the other hand, when the pile diameter of the group increases, the frequency, at which the maximum displacement occurs increases hence the system becomes more stable against resonance condition.