Abstract
The final presentation, Part IV, completes the third phase of this study in which the dynamics of building-foundation-soil interaction is investigated with regard to its basic mathematical structure. This follows a consistent formulation of the problem having been given in the latter half of Part III, and employs a shear-beam modelling of superstructure reduced to a bare simplicity. Again, a set of general theories developed in Part I is repeatedly referred to in these examinations. Complicated and nonelementary appearences are first emphasized concerning the poles and associated residues on the complex frequency plane. In particular, an interesting and novel phenomenon of pair-swapping can be pointed out when arranging the poles into the set of complex or real conjugate couples. On the basis of the root-square values of unit impulsive response, dynamic response properties to free-field acceleration are then discussed in detail, which alternatively corresponds to examining the root-mean-square amplitudes of random response under white noise excitations. After clarifying the differing role of specific poles, the results obtained are also interpreted in such elementary points as the Voigt-equivalent and random function characteristics. Absolute acceleration at the base of superstructure is among the matters of primary concern in the latter study.
