Seismic Response of a Variable Cross-Section Shear Beam Building with Soil-Structure-Interaction

In here, we investigate the response of a cantilevered shear building to seismically induced ground motions in the presence of soil-structure-interaction phenomena. The novelty of the present approach lies in the representation of the variable stiffness of the structure using a distributed mass model that is exact in terms of
the theory of elastodynamics. The ensuing modal analysis of the shear beam requires recovery of the system eigenmodes from
the governing differential equation with non-constant coefficients in terms of a power series expansion. Next, the equations of the complete system comprising structure, foundation, surrounding soil plus a base isolator are combined in the frequency domain, yielding a non-symmetric matrix system. Upon solution in terms of frequency response spectra, the time response is reconstituted through use of the inverse Fourier transformation. Finally, a parametric study is conducted to investigate the influence of the surrounding soil and of the base isolator on the kinematic response of the structure.