地域的な震源スケーリング則を用いた大地震(M7級)のための設計用地震動予測 PREDICTION OF STRONG GROUND MOTION FOR M 7 EARTHQUAKE USING REGIONAL SCALING RELATIONS OF SOURCE PARAMETERS
We propose a synthetic procedure for predicting strong ground motion at a specific site from a future large earthquake using a semi-empirical method. First, we estimate regional scaling relations of source parameters based on the earthquake observation in the objective region. Next we propose the operations to correct the empirical Green's functions by considering the differences in stress drop, attenuation effect, Fmax, and radiation patterns between large and small earthquakes. The above method is applied to ground motion prediction for future earthquake (M=7, Δ=13km) caused by NEGORO fault in Wakayama, Japan. Here, we utilize 7 small-events with magnitudes of 3.3〜4.4, judging from the event locations and source characteristics. We evaluated the variation of ground motions synthesized using different small-event motions individually as empirical Green's functions, and we obtained the results wherein the peak acceleration and velocity of the synthetic motion using the small-event record of M 4.4 are comparable to the empirical values, estimated from Watabe's and Kanai's formulas, respectively, and the upper limits of the synthetic velocity response spectra show good agreement with the design response spectra by Osaki. On the other hand, synthetic motions using the records of smaller events than M 4, individually, as empirical Green's functions, tend to be underestimated compared with the empirical values, although the envelopes and the spectral shapes are similar to each other.
日本建築学会構造系論文報告集 416(0), 57-70, 1990