As the 1999 Chi-chi earthquake and the 1999 Kocaeli earthquake damaged many important structures due to surface rupture as well as a strong motions induced by the earthquake faults, displacement and inclination of ground surface have become the significant issues in engineering. Most analytical methods do not evaluate displacement and strong motions at the same time. Iwata et al. (2016) conducted fault rupture simulation using three dimensional finite element method (3D-FEM) for the 2014 Nagano Prefecture Earthquake caused by the rupture of Kamishiro Fault. While the surface displacement response was in good agreement with the actual displacement, the acceleration response was not well simulated due to FEM mesh size, constitutive relation of fault plane and so on.
In this study, the authors revised simulation conditions such as damping ratio, spring stiffness of joint elements, FEM mesh size of a fault plane and the constitutive relation during stress drop to evaluate the acceleration response together with the consideration of the surface rupture. The computational results confirmed that the displacement and strong motion can be evaluated simultaneously using appropriate constitutive parameters and fine FEM mesh with a size less than 150m.