Abstract
Ground motion inputs to building structures are multidimensional and cause complex responses. In this paper, particle orbit characteristics of horizontal ground motion are described. A 2-layer subsurface structure model is used for analysis based on the 1-dimensional wave propagation theory. Shear torsional motions and motion coupling between translational and torsional motion are considered. The site response and the horizontal particle orbit of ground motion are characterized by the coupling parameters. The effects of the coupling parameters to the ground motion are investigated through a theoretical approach and numerical experiments.
