A stochastic finite‐fault approach based on corner frequency (EXSIM) is applied to simulate the Tottori Mw 6.2 earthquake. The parameter κ0 is calculated based on ground motion recordings. Other parameters, such as quality factor (127f0.61) and stress drop (27.97 bars) are taken from our earlier work. The slip distribution refers to the results of Kubo et al. (2017, https://doi.org/10.1186/s40623-017-0714-3). The geometric spreading function and ground motion duration are taken from Atkinson and Boore (1995, https://doi.org/10.1785/bssa0850010017). The simulated results match well with the observed values in a short period (T < 1 s). In addition, the effects of hanging wall (HW) and footwall (FW) on the simulated values are discussed. The results show that the simulated results of HW stations are more consistent with the observed values than those of FW stations. The differences between simulated Pseudo Spectral Acceleration (PSA) and observed PSA with epicentral distance and azimuth are also analyzed. The results show that the local site amplification and geometric location of stations influence the simulation results for soft soil sites. Overall, the simulated ground motions obtained by applying EXSIM approach matched well with the observed recordings which could be considered as the basis for earthquake‐resistant design during the post‐disaster recovery and could become a powerful tool for earthquake ground motion prediction.

To eliminate the effect of the subfault dimension on the synthetic ground motion of the stochastic finite-fault technique, Motazedian and Atkinson developed the dynamic corner frequency. Furthermore, they derived a high-frequency scaling factor based on the velocity spectrum to compensate for the underestimation of the ground-motion source spectrum amplitude in the high-frequency range caused by the dynamic corner frequency. However, this high-frequency scaling factor was developed on the assumption that the slip amount, seismic moment, and the high-frequency received energy of each subfault on the rupture surface were the same. Considering the nonuniformity of the slip of each subfault and the large amount of received energy released on the asperity body, the received energy of the entire fault was distributed to each subfault according to the ratio of the slip of the subfault to the total slip. This could ensure not only that the high-frequency received energy radiated by the subfault with a large slip was greater but also that the total received energy was conserved. Finally, an example was used to discuss the effect of the improvement on the synthetic ground motion. The results showed that the proposed improved approach can further eliminate the dependence of the synthetic results on the dimension of the subfault.

Stochastic finite-fault method is the main method to simulate near field strong earthquakes in current seismic engineering. For specific ground motion, the accuracy of parameter selection is important, such as field effect, because the number of rock sites is scarce in many areas of China, the calculation of crustal amplification and site amplification of a specific soft soil site can not only eliminate the limitation of station selection, but also improve the accuracy of simulation results. In this paper, a stochastic finite-fault method based on dynamic corner frequency is used to simulate the Mw6.2 Tottori earthquake on October 21, 2016 in Japan. The comparison with the actual records shows that the simulation results are in good agreement with the short period and have great feasibility. This paper discusses the differences between the simulated response spectra (PSA) of stations with various azimuths and the observed one. Meanwhile, it also demonstrates the dissimilarities in simulation results between the stations located on the hanging wall and those located on the flat wall of the fault plane. The results show that for soft soil sites, crustal amplification and site amplification, as well as the geometrical position relationship between stations and faults have a certain impact on the simulation results. Based on the calculation of specific crustal amplification and site amplification in a specific region, the location relationship between stations and faults is included in the analysis, so that the future earthquake can be predicted more accurately, and an important reference can be provided for the disaster assessment in this region and the site selection of major projects.