Study of role of basin shape in the site-city interaction effects on the ground motion characteristics

In this paper, the role of basin shape in the site-city interaction (SCI) effects on the ground motion characteristics is documented. The effects of city type and city density on the free-field motion are also documented. The seismic responses of various 2D basin models with different shapes as well as city type and city density were simulated using a fourth-order accurate staggered-grid viscoelastic SH-wave finite-difference algorithm. The analysis of simulated responses of various site-city models, ground motion perturbations and spectral amplifications revealed that basin shape plays an important role in SCI effects on the ground motion. Further, a considerable SCI effect was obtained at the double resonance. The city density seems to be a more prominent parameter of SCI, which largely reduces the ground motion amplitude in the city as compared to the height of buildings. It was also inferred that the existence of different types of buildings may result in a decrease in coherency of building response.