Seismic Response of Single-Story Interaction Systems

The influence of the flexibility of the foundation medium on the seismic response of a class of typical single-story structures is examined. The foundation medium is represented by an isotropic elastic half-space, while the ground acceleration is simulated by a transient time dependent function which exhibits characteristics resembling those of strong motion earthquakes. The solution of the equations of motion shows that the flexural displacement of an interaction system can be greater or less than the response of the same structure on a rigid foundation. On the basis of a parametric study, simple relationships are given which permit the use of spectral velocity curves for estimating the maximum flexural response of single-story structures on flexible foundations. The proposed technique yields, for both pseudo and actual strong motion earthquakes, results which are in good agreement with the maximum flexural response obtained from the solutions of the equations of motion.