Investigating the Effects of Underground Structures on the Scattering of Seismic Waves Reaching the Ground Surface

The realistic understanding of the scattering of unground structure-induced seismic waves, known as amplifications on the ground, can lead to the design of safe and strong structures on the ground. In the present study, FLAC Software is applied to investigate different models of the Daikai subway station, which was heavily damaged in the 1995 Kobe earthquake. The responses of the ground were analyzed with and without the structure to examine the phenomenon of amplification. The results show the maximum amplification of 2.2 recorded in the middle point of the structure, while the maximum acceleration peak was recorded in a point adjacent to the edge of the structure. Among different points in soil layers, those that were in contact with the structure experienced the highest enhancements compared to the case without the structure. In the next step, different models of the structure with the central column thicknesses of 10–70 cm were developed to investigate the lateral displacements of the structure. The results indicated that the maximum lateral displacement of the structure between the maximum and minimum thicknesses was smaller than 10 mm.