Probabilistic Use of Arias Intensity in Geotechnical Earthquake Engineering

When earthquake engineering is concerned with both the amplitude and durational aspects of ground motion, it commonly uses seismic loading in the form of a time history. The translation of traditional probabilistic seismic hazard analysis (PSHA), i.e., based on peak acceleration/response, into a time history can be complicated by deaggregation sensitivity to choice of motion parameter. The complication is exacerbated when peak motion only partially addresses damage potential. Energy-based parameters, such as Arias Intensity, address both amplitude and durational aspects of seismic shaking. To the extent that energy content correlates with damage potential, PSHA using AI (or some other energy measure) yields hazard curves that facilitate the translation of probabilistic load into a time series and, through deaggregation, facilitates the development of design earthquake scenarios and time histories. Potential applications range from assessing the conservatism of a time history's loading, to developing a suite of time histories with specific probabilistic loads for damage sensitivity analysis. Examples of AI-based and peak acceleration-based PSHA for exceedance return periods suggested for dams (thousands of years) show that AI-based deaggregation focuses on larger earthquakes where peak acceleration-based deaggregation indicates competing scenarios.