Maximum Direction Spectrum and Ductility Demand for Earthquakes in a Stable Continental Region

Abstract

This thesis compares the ductility demand spectra for single degree of freedom (SDOF) systems in the active tectonic region (ATR) to stable continental region (SCR) using the maximum direction suggested by ASCE 7-10. The ATR earthquakes and SCR earthquakes are known to have different stress drop characteristics. However, the current Korean seismic design codes are made without considering the difference of the earthquake from two regions and uses the ATR earthquake ground motion data. Secondly, Geometric mean (GeoMean) is used in the current design code to make the two horizontal ground motions into one measure however orientation dependency exists, in contrast, maximum direction (MaxDir) is orientation independent and therefore a more conservative design method. Earthquake ground motion data is collected for the ATR and SCR and the design response spectrum is constructed for comparison. Also, the ductility demand in the two regions are compared using the maximum direction. Additionally, ductility demand spectrum are constructed using two material models, bilinear model (Von Mies Model) and smooth hysteresis model (Bouc-Wen Model) and the two model are compared. This thesis concludes with the suggestion of using the maximum direction spectrum and SCR earthquake ground motion data for the future seismic codes in Korea.