
Accession Number : AD0469600
Title : VERTICAL MOTION OF RIGID FOOTINGS.
Descriptive Note : Final rept.,
Corporate Author : MICHIGAN UNIV ANN ARBOR COLL OF ENGINEERING
Personal Author(s) : Lysmer, John
Report Date : JUN 1965
Pagination or Media Count : 137
Abstract : This work deals with the vertical mode of vibration of a rigid circular footing resting on a plane soil surface and excited by a vertical timedependent force in the axis of symmetry. It is assumed that the subsoil can be considered as a perfectly elastic, isotropic, and homogeneous half space. First an approximate theoretical solution is developed for the steadystate motion of the above halfspace model. This solution differs from previously published solutions in that it includes all frequencies of excitation. It is then shown how the transient response due to a pulsetype loading can be calculated from the steadystate solution by a simple Fourier technique, and a computer program using this technique is presented. Parallel with the above development it is shown that the elastic halfspace model behaves very similarly to a simple damped oscillator, and the author proposes the use of a simplified analog of the massspringdashpot type for practical calculations. The above theoretical results are supported by the presentation of both steadystate and impact tests performed by other researchers. (Author)
Descriptors : (*STRUCTURES, SUPPORTS), (*SUPPORTS, VIBRATION), MOTION, SOILS, PRESSURE, EQUATIONS, MATHEMATICAL ANALYSIS.
Distribution Statement : APPROVED FOR PUBLIC RELEASE