Influence of the Lateral Heterogeneity of Shallow Sediments on Site Effects in the Yuxi Basin

As computing power and ground motion studies using numerical simulation methods have continuously improved, velocity model accuracies have become bottlenecks for simulation result accuracies. The characteristics of a hydrodynamic sedimentary environment in the Yuxi Basin are used as a classification standard, and a refined velocity model that depends on the lateral heterogeneity in sediments is constructed. The results of the lateral heterogeneity model are compared with those of the lateral uniformity model, and the distributions of the displacement peak ratio, focusing effect and edge effect change due to the refined basin structure. For the 4% of the surface area that is in the region with the largest amplification factor, the difference between the two models is greater than 20%, and this difference for nearly half of the surface area is greater than 5%.