Seismic design response of structure subjected to six components of earthquake

A complete description of the earthquake-induced ground motion requires definition of six components. These components, defined along a set of structural axes will be statistically correlated with each other. In this paper, the three rotational components are defined in terms of the translational components and the correlation between the six components is then analytically established. As the correlation varies with the orientation of the structure and affects the response, some orientations may induce larger response than others. A method is developed to obtain the largest response, irrespective of the structural orientation. The numerical results obtained for the maximum response are presented. It is shown that the effect of the rotational components can be quite large, especially for large structures. (orig.)