EFFECTS OF ANGLE OF INCIDENCE OF SH-WAVE AT THE BASIN-EDGE ON THE CHARACTRISTICS OF BASIN-EDGE INDUCED LOVE WAVE

Abstract

This paper presents the effects of angle of incidence of SH-wave at the basin-edge on the characteristics of basin-edge induced Love waves and associated strain and aggravation factor (aggravation factor is simply the extra spectral amplification due to complex 2D site effects over the 1D response of the soil column). The linear seismic responses of basin-edge model with various edge-slopes were computed using SH-wave finite difference algorithm with second-order accuracy in time and fourth-order accuracy in space. The analysis of simulated results revealed an increase of amplitude of induced Love waves, differential ground motion (strain), and aggravation factor with decrease of basin-edge slope and increase of angle of incidence of SH-wave at the basin-edge. Maximum strain of the order of 9.23 × 10-4(for 1.0 cm peak ground displacement at the bedrock) was obtained at an offset of 60.0 m (0.47λF0, where λF0is the fundamental wavelength), in case of 84.4° angle of incidence of SH-wave. Further, the percentage increase of strain with respect to the strain in case of normal incidence of SH-wave was almost equal to the angle of incidence of SH-wave at the basin-edge.