2024 Volume 80 Issue 23 Article ID: 24-23335
We investigated a method to easily evaluate the natural period of the surface ground using open data on the average S-wave velocity and geomorphologic classification of the surface ground in the Kanto region. Based on the index converted from the average S-wave velocity in the surface layer of 30 m and the grouping by geomorphologic classification, a prediction formula for the natural period of the surface ground was derived, and it corresponded well with the observed values obtained from PS logging. The results of calculating the natural period using the proposed prediction formula for locations in Tokyo and Chiba Prefecture, it was found that the predicted values and observed values correspond well. Furthermore, it was shown that the proposed formula can evaluate the natural period of the surface ground with higher accuracy than the practical method.
