Modeling Worst-case Earthquake Accelerograms for Buildings and Structures

摘要

Input data necessary for synthesizing accelerograms are usually derived from seismic behavior of the construction site or from a statistical analysis of a set of recorded accelerograms which correspond to this particular construction site. As seismic performance of the site is independent of the structure which is supposed to be built on it, dynamic properties of the structure are usually not taken into account when compiling the input data. However, the available input data must necessarily contain the uncertainties generated by randomness inherent in the nature of seismic action. Hence the input data must be governed by certain laws of distribution. Therefore, we can use the input data which are possible for the construction site with a predefined probability and pose the gravest threat to the structure. In turn, in order to identify which of the accelerograms can possibly be the most dangerous for the structure, dynamic properties of the structure must be considered. This article defines a methodology for generating the worst-case accelerograms for buildings and other structures and presents a concrete example of generating a linear cantilever type system with a finite number of degrees of freedom.