SCEC Award Number 18020 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Modeling shallow crustal nonlinearity in physics-based earthquake simulations: Beyond perfect plasticity
Investigator(s)
Name Organization
Domniki Asimaki California Institute of Technology Ricardo Taborda University of Memphis Doriam Restrepo Universidad EAFIT (Colombia)
Other Participants Elnaz Esmaeladeh Seylabi
SCEC Priorities 4a, 4b, 4c SCEC Groups GM, CS, EEII
Report Due Date 03/15/2019 Date Report Submitted 04/14/2019
Project Abstract
 One of the outstanding questions in our understanding and simulation capabilities of physics-based earthquake scenarios is the extent to which nonlinearities in the shallow crust influence ground motions. In this proposal, we advanced SCEC's simulation capabilities to address this question by implementing and testing constitutive models that go beyond traditional elastic-perfectly plastic (Drucker-Prager) approaches. After implementing the models on the finite element platform Hercules, optimizing and verifying the implementation, we used them to analyze idealized models of 1D nonlinear site response and 3D nonlinear basin effects; and compared results to those obtained using Drucker-Prager, the constitutive law currently implemented on Hercules and AWP-OCD for regional ground motion simulations with plasticity. Results reveal significant differences in the stress-strain loops and time-series predicted by the two approaches and call for more in-depth investigation. Our ongoing efforts are focusing on this next step by modeling the nonlinear basin response of Garner Valley, and comparing results to strong motion recordings. This project was aligned with SCEC5's beyond elasticity theme, and with the science priorities set in the 2018 Science Plan to investigate how strong ground motions depend on the complexities and nonlinearities of dynamic earthquake systems.
Intellectual Merit One of the outstanding questions in our understanding and simulation capabilities of physics-based earthquake scenarios is the extent to which nonlinearities in the shallow crust influence ground motions. The intellectual merit of this proposal lies in advances made in SCEC's simulation capabilities to address this question by implementing and testing constitutive models that go beyond traditional elastic-perfectly plastic (Drucker-Prager) approaches.
Broader Impacts This project was coordinated by a female postdoctoral fellow at Caltech, who recently accepted an offer for a junior faculty position at the University of Nevada at Reno. Results will promote SCEC's vision to investigate how strong ground motions depend on the complexities and nonlinearities of dynamic earthquake systems.
Exemplary Figure Figure 4: Acceleration responses in idealized basin: elastic-3D, J2 model-3D, MCP model-3D, MCP-model-1D.