Topographic and near-surface stratigraphic amplification of the seismic response of a mountain slope revealed by field monitoring and numerical simulations

peer reviewedThe evaluation of seismic site amplification and its relationship with geological structures play a vital role in earthquake engineering and hazard assessment. This study presents an analysis of topographic and geologic site amplification effects observed in the Qiaozhuang region, Sichuan Province, China. Seismic recordings at several monitoring stations installed on two slopes located at a distance of about 1 km in the study area after the 2008 Wenchuan earthquake provide evidence of strong and variable amplifications. To assess the combined effect of topographic and geological controls in slope response to seismic motions, we built 2D and 3D dynamic numerical models using monitoring data as inputs. Four layers with different P-wave velocities, based on geophysical survey in the study area, are considered in the numerical models. Models that only consider topography give an amplification factor of