2005 年 58 巻 4 号 p. 331-338
It is important to understand the detailed 3-D subsurface structure to estimate the strong ground motions. For this purpose, we will confirm the usability of the gravity survey and propose a process from modeling the ground structure to estimate of the strong ground motions.
The gravity survey has been carried out to estimate the 3-D subsurface structure around the damaged area due to the 1909 Anegawa earthquake. Steep slopes of the bedrock are located around the severely damaged area. On the basis of the estimated 3-D subsurface structure, the strong motions are numerically simulated by using the finite-difference method (FDM). From the results of the simulations, it is shown that the peak ground velocity correspond to the collapse ratio of the wooden structures except for some cases.