Simplified approaches for Arias Intensity correction of synthetic accelerograms

Abstract

For the generation of synthetic accelerograms, spectrum compatibility is usually emphasized. However, it is well known that the correct evaluation of the seismic response depends on suitable seismic inputs. For example, Arias Intensity, that measures the energy of an earthquake and which attracts more and more attention in probabilistic seismic analysis, cannot be ignored. Thus, simplified methods which could generate both spectrum-compatible and energy-compatible accelerograms are required. This study focuses on the correction of Arias Intensity when generating artificial synthetic accelerograms for given specific earthquake records. Two simple and efficient approaches are proposed. The first approach introduces an energy-compatible algorithm to the spectrum-compatible model, which enables the generated accelerograms to match both the target response spectrum in the frequency domain and Arias Intensity in the time domain. The second approach refers to an empirical way in which empirical envelope shape functions are directly defined based on the energy distribution profile of given earthquake records. The two approaches are validated using various earthquake records, their performance is proven satisfactory and their application is straightforward in the relative fields of earthquake engineering.