摘要(英) |
In recent years, a topic of considerable research interest in the engineering seismology is to predict a suitable ground motion for seismic evaluation of a structure or earthquake risk assessment of a designated site.
This study uses the discrete Fourier transform method to predict seismic ground motion of a recording site. The accelerograms at the recording site are divided into four sites according to which the location of epicenter, and for each site the suitable distributions of probability density function are selected to model Fourier spectrum and group delay time with the associated parameters being regressed as function of earthquake magnitude. Thus, with the given magnitude, predicted accelerograms can be generated using the inverse Fourier transform.
The earthquake records with magnitudes equal to or greater than 5.0 from the Jr-Nan Temple Station in Taipei are selected for this study. For the Jr-Nan Temple Station, the following conclusions can be drawn:(1)the Fourier spectrum of records can be modeled as a lognormal probability density function;(2)separated frequency range into ten intervals group delay time of records can be modeled as a normal probability density function in each interval;(3)if more records with the epicenters located within small region are available, the accuracy of the predicted motion originated from that region can be enhanced;(4)if two regions have the same numbers of epicenter, the accuracy of the predicted ground motion originated from the region with epicenters spread over a small area will be better. |
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