Influence of rupture velocity of the directly-beneath fault on the basin seismic effect

Earthquakes caused by strike-slip fault often lead to serious earthquake damage to the cities above the basin when the fault rupture parameters have a significant effect on basin amplification. In this paper, the simulation accuracy of 3D spectral element method for near field vibration is contrasted under the kinematic source model based on the finite fault rupture. Then, by comparing the distribution characteristics of seismic intensity and amplification factor between the basin model and the one-dimensional horizontal layered model with no basin, the influence of the rupture velocity of the fault buried directly beneath the basin on the seismic effect of the basin is studied in detail. The results show that the existence of the basin will significantly change the distribution characteristics of near-fault ground motions, but the distribution characteristics of strong ground motions of different components in the basin will be significantly different. The amplification factor appears different distribution characteristics from strong ground motion with the influence of basin effect. The influence of fault rupture velocity on seismic effect of basin is significant. With the increase of rupture velocity, the ground motion intensity of the basin increases gradually, but the increase rate of different components is significantly different. The amplification factor of the basin overall shows a trend of decreasing with the rupture velocity increasement, but the influence degree for the amplification factor of different components is obviously different. Meanwhile, the location of the area with strong amplification in the basin is also significantly affected by the rupture velocity, but generally concentrated on both sides of the fault as well as near the basin edge perpendicular to the rupture direction.