2020 Volume 20 Issue 1 Pages 1_118-1_132
During the 2016 Kumamoto earthquake, surface rupture of seismic faults occurred over a wide area. Simultaneously, large-amplitude pulse waves were recorded in the vicinity of the seismic faults. Herein, we present a theoretical evaluation of the near-fault seismic ground motions, which requires a fine division of the fault plane into many sub-faults. Numerical convergence of the spatial integration is examined using the Thin Layer Method (TLM). We found that permanent displacement and dynamic velocity converge using an integration spacing equal to approximately half of the fault shortest distance by comparison with rigorous methods. Finally, we applied the seismic fault model to the main shock of the 2016 Kumamoto earthquake to investigate the influence of differently divided sub-faults in the fault plane on the evaluation of strong ground motions adjacent to the seismic fault.
