MOTION OF FOUNDATION ON A LAYERED SOIL MEDIUM .2. RESPONSE ANALYSIS

The objective of the present approach is to determine the structural r esponse to external force excitations and earthquake excitations with consideration of soil-structure interaction. The physical model concer ned is a flexible structure resting on a rigid or flexible foundation embedded in a layered soil medium. The vibration of the structure is f irst analyzed using the wave propagation approach without reference to the interaction. The interaction effect is recovered by the impedance relationship developed in the companion paper. In an attempt to use t he free field ground motion as the input to the system, the Maxwell's reciprocal theorem is applied to remedy the difference between the fre e field and real ground motion in the presence of the structure. As a result, the structural response at any location is written as a linear function of external excitations and the seismic source. Such a solut ion form is convenient for statistical analysis. (C) 1997 Elsevier Sci ence Limited.