Dynamic behaviour of building‐foundation systems

Abstract A discussion of the effects of soil‐structure interaction on the dynamic response of linear structures which respond as single‐degree‐of‐freedom systems in their fixed‐base condition is presented. The structures are presumed to be supported at the surface of a homogeneous, elastic halfspace and to be excited at the base. The free‐field ground motions investigated include a harmonic motion, a relatively simple pulse‐type excitation and an actual earthquake record. Comprehensive response spectra are presented for a range of the parameters defining the problem, and the results are used to assess the accuracy of a simple, approximate method of analysis in which the system is represented by a viscously damped, simple oscillator. Special attention is given to defining the conditions under which the interaction effect is of sufficient importance to warrant consideration in design. The method of analysis used to obtain the numerical data reported herein is reviewed only briefly, the emphasis of the paper being on the interpretation of the results.