SCEC Award Number 22033 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Lab-Based Ground Motion Simulation Using a 3D-Printed Physical Model of the Los Angeles Basin
Name Organization
Sunyoung Park The University of Chicago
Other Participants Jiong Wang (Postdoctoral Scholar; The University of Chicago)
SCEC Priorities 4a, 4c, 4b SCEC Groups GM, Seismology, CXM
Report Due Date 03/15/2023 Date Report Submitted 05/03/2023
Project Abstract
We study high-frequency ground motions and basin effects from seismic experiments on a physical model of the Los Angeles Basin. Previous study (Park et al., 2022) has demonstrated that lab-based seismic experiments on the 3D printed model can effectively produce ground motion data that are consistent with the input velocity structure. Through this project, we have (1) conducted examination of additional data including those for sources inside and outside the basin and also (2) developed a data filtering method for lab-generated ground motion data.
Intellectual Merit The project contributes to several SCEC science priorities. First, our physical model represents the heterogeneous structure across the Los Angeles Basin with uneven basin interfaces. We examine the roles of such heterogeneities on the ground motions, which directly contributes to P4.a. Second, lab experiments on the physical model provide a completely new means of ground-motion simulation that is (1) not affected by theoretical and numerical assumptions and (2) not limited by the computing power when simulating high-frequency ground motions. Therefore, this project directly contributes to P4.c.

Furthermore, continued work using this new approach has potential in validating the CVMs, in particular, the merged multi-scale models (P4.b). Following the current 3D printed model, a simplified version of the current SCEC CVM-H (Shaw et al., 2015), we can print downscaled replicas of updated CVMs and compare the lab-based and observed ground motions in the future. Finally, our lab-based ground motion simulation approach provides a new way to understand the effects of nonlinearity on wave propagation, which aligns with P2.b. Since our approach can provide the “ground truth” ground motions, we can study the validity of using linear wave propagation as an approximation.
Broader Impacts This project involved training of a postdoctoral scholar and a graduate student. It also supported the graduate student's first attendance and presentation at the SCEC conference.
Exemplary Figure Figure 2. Record section (top) and spectra (bottom) for the data collected for a "labquake". Red dashed lines denote the locations of edges of basins, where frequency contents of ground motion changes clearly. For the spectra, there is an additional vertical axis on the right showing the frequency in the laboratory scale.