Machine foundation response subjected to vertical vibration: experimental and analytical using cone model
A. Amiri, S.N. Moghaddas Tafreshi, Andrew Dawson, Sassan Mohasseb
Abstract
The fundamental aim in the proper design of machine foundations is to limit the response amplitude by preventing resonance in all vibration modes. The effects of static and dynamic forces and embedment depths for foundation-induced vertical vibration have been examined, experimentally and analytically using the Cone model. Therefore, various vibration indicators such as displacement amplitude, resonance frequency and complex dynamic stiffness were evaluated. Finally, the statistical properties, Quantile-Quantile plots, and Root-Mean-Square Error values were used to gain confidence in applying the Cone model for predicting the soil bed dynamic behaviour. Per the results, it was observed that embedment increases resonance frequency, natural frequency ratio and damping ratio while the maximum resonant amplitude reduces as the embedment depth increases. Given the findings, due to the increasing dynamic force, a drop in resonance frequency and a rise in peak displacement amplitude of the foundation bed were observed. On the other hand, resonance frequency and amplitude are attenuated with an increase in static force level. Further, the complex dynamic stiffnesses predicted by the Cone model shows good agreement with that obtained experimentally. Thus, whenever feasible, the convenient and relatively accurate Cone model can be performed for assessing foundation vibration in practical engineering projects.