Improvement and comparison on methods of generating artificial ground acceleration

Base-isolated and energy-dissipated buildings in Taiwan have been gradually increased. It is necessary to design those buildings by using the time history analysis. For such an analysis, the inputs should be artificial ground accelerograms compatible with a design spectrum. Under the regulation of the domestic seismic design code, this article discusses several methods in generating the artificial ground acceleration, and then compares the results. The modification method proposed by this article, named single period with maximum deviation method, adds a number of time histories with different periods and durations to a real seismic record for generating the spectrum-compatible artificial ground acceleration. This method owns high operation efficiency to modify the real record with narrow duration and amplitude. In this method, it is suggested that the damping ratio of the modification time history is 5% and the period step is 1% of the fundamental vibration period of a building in order to satisfy the compatibility criteria in the specified period range.