Examining the Effects of Basin Interfaces on Ground Motions with Lab-Based Seismic Data Obtained Using a 3D-Printed Basin Model

Abstract We investigate the effect of detailed basin interface structures on ground motions based on a lab-based seismic dataset derived from a cutting-edge 3D-printing-based methodology. This is enabled by the first in-depth, quantitative analyses of such data. We first examine a scenario where the lab-based earthquake source is located inside a basin and find that the reverberation of body waves can coincide with high-amplitude surface waves, leading to further amplification of ground motions. We also examine a case where the earthquake source is outside a basin and seismic waves are traveling toward the basin. We identify significant seismic energy reflecting from the intricate basin interface structures, particularly at steep parts of the interface where the basin depth changes abruptly. These reflections contribute to amplified ground motions near these steep basin interfaces. Furthermore, we find that relatively low-frequency waves can reflect off basin interface structures with length scales as small as approximately one-eighth of their wavelengths. Our study highlights the importance of incorporating detailed basin structures for accurate ground-motion assessments, demonstrating that this 3D-printing-based approach provides an effective means for achieving that.