Abstract
Modeling phase characteristics of earthquake motion is important to synthesis a design earthquake motion compatible with the given response spectra. We used the concept of group delay time to develop a model of phase spectrum. Applying wavelet deconvolution to an earthquake motion we calculate the average value of group delay time and its standatd deviation in each compact support. Collecting earthquake motions from recent earthquake data sets a regression analysis was performed to obtain an attenuation relation of average group delay time and its standard deviation in each compact support. Assuming the normal distribution characteristic of group delay time we simulated a group delay time and then the phase spectrum by integrating it inside of each compact support.
