Robust Building Stiffness Design for Variable Critical Excitations

Abstract

Since earthquake ground motions involve various intrinsic and epistemic uncertainties, it is difficult even with the present knowledge to predict forthcoming events at a specific site in a reasonably accurate way. It is therefore desirable to develop a robust structural design method taking into account these uncertainties even partially. Critical excitation or worst-case analysis approaches are making remarkable progress recently and seem to be promising as a candidate to overcome such difficulties. In this paper, the power (area of power spectral density function) and the intensity (magnitude of power spectral density function) are fixed and the critical excitation is found under these restrictions. A design problem for restricted variable design earthquakes is formulated as a minimum–maximum problem which is expected to lead to the maximum global performance design for variable critical excitations. The elastic–plastic response characteristics of the building models designed by the present method are revealed for a broader class of excitations and code-specified design earthquakes.