Concepts and Problems in the Design of Foundations Subjected to Vibrations

The main criteria for safe performance of machine foundations subjected to dynamic loads are to control excessive displacements that depend on the resonance condition attained by the foundation-soil system. Several factors such as: dynamic properties of soil supporting the foundation, static weight of the foundation and vibrating equipment, area of contact of the foundation with soil, static soil pressure, nature and magnitude of unbalanced force have major influence on its behavior. The nature of dynamic loads and non-homogeneity of soil make the analysis and design of foundation subjected to dynamic loads to be more complex. The main objective of this paper is to present a parametric study on the influence of the rigid base on the response of the foundation-soil system. It stresses on the importance of accounting for the presence of rigid surface such as a shallow rock beneath the soil in the design of machine foundations.