Abstract

Due to the wave interference occuring inside the alluvial valley, the displacements on the ground surface can be largely amplified and cause severe damage to the infrastructure. Numerous studies have been conducted to investigate the surface displacements of the valley subjected to the propagation of the SV shear wave. However, most of the work deal with homogeneous valleys, which is an ideal simplification and can not reflect the reality. Practically, the alluvial valley consists of multiple layers of soil. The material contrast between soil layers causes reflection and scattering at the soil interface, leading to a more complicated displacement field. Accordingly, this manuscript analyzes the ground surface displacements of the two-layer alluvial valley subjected to the oblique incidence of SV wave, using 2D finite element models. The results of the numerical models were initially verified with those from a published paper. Subsequently, this verified model was used to analyze the effect of material contrast, incident angle and frequency of the shear wave on the displacement field of the ground surface by means of the amplification factor (AF). The results of the simulation show that the lateral and vertical displacements are amplified 32 and 22.3 times, respectively, compared with the magnitude of the incoming SV wave. The values of AF tend to increase with increasing material contrast and less fluctuate with increasing frequency of the incident SV wave.