Seismic waves amplification: Experimental versus numerical analysis

The specific site considered is located in the center of Nice on the french Riviera. Experimental results (microtremors, real earthquakes) on seismic motion amplification are firstly analyzed. Afterwards, site effects are investigated considering the boundary element method in the frequency domain. A pure plane SH-wave is taken as the seismic loading considering various incidences. The analysis of site effects through this numerical approach gives quantitative results on both following parameters: the amplification level and the location of its highest values. The influence of frequency and incidence is also analyzed. This numerical study is very interesting since it gives many qualitative and quantitative results about seismic waves amplification in alluvial surface layers. The thickness of the layer(s), its general shape as well as its mechanical characteristics have a great influence on the maximum amplification factor and the frequency for which it occurs. Comparisons between experimental and numerical results are good and may lead to improvements of both approaches. For instance, further studies on three-dimensional effects would be of great interest.