Rocking Vibrations of Footings

To predict the response of a machine foundation subjected to rocking vibrations, analytical solutions for three cases of contact pressure distributions, namely, rigid base, uniform and parabolic have been developed and are presented in the form of curves for ready use. Carefully controlled field vibration tests have been carried out on footings of various sizes and masses, resting on soil surface and subjected to horizontal vibrations which generate coupled rocking and sliding vibrations, to check the validity of the analytical solutions. The experimental investigation conducted is reported in detail. It is shown that the newly developed analytical solutions are quite satisfactory to predict the response of a machine foundation subjected to rocking vibrations, as well as predicting the rocking component of the coupled rocking and sliding vibrations, from a single field vibration test.