Abstract
In this paper, a method for generating a pseudo earthquake ground motion is proposed. In the method, we utilize strong motion records which was used in the generalized inversion technique (GIT) and estimated parameters of the GIT. First, source spectrum evaluated by the GIT and path effect used in the GIT are removed from Fourier amplitude spectrum of the strong motion record. Then, many site amplitude factors (as many as the number of earthquakes) are gained. Second, pseudo earthquake ground motions are generated based on the site amplitude factors and an arbitrarily selected earthquake ground motion. In the method, there is no need to rely on random numbers. Thus, pseudo earthquake ground motions which have natural continuity between frequency points in the Fourier amplitude spectrum can be obtained. Furthermore, we apply the proposed method in the case of KNG003 (one seismic observation station of the K-NET in Japan). Seismic coefficients, which is needed for designing port and harbor facilities and velocity power spectrum intensity (PSI) are calculated from the generated pseudo earthquake ground motions. Finally, mean and standard deviation of the seismic coefficients and the PSIs are calculated, and probability distribution of seismic coefficients are evaluated for the case study of the KNG003.
