SCEC Award Number 16028 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Modeling and implementation of a stochastic geotechnical layer for physics-based ground motion simulations
Investigator(s)
Name Organization
Domniki Asimaki California Institute of Technology Ricardo Taborda University of Memphis Alan Yong United States Geological Survey
Other Participants Jian Shi, California Institute of Technology (Graduate student)
SCEC Priorities 6e, 6c, 6b SCEC Groups GMP, GMSV, CME
Report Due Date 03/15/2017 Date Report Submitted 04/06/2017
Project Abstract
Near-surface soil layers of sedimentary basins play a critical role in modifying the amplitude, frequency and duration of earthquake ground shaking. Referred to as site e ffects, these phenomena are essential elements of evaluating earthquake hazard and risk on a regional scale, through statistical models such as ground motion prediction equations, and wave propagation simulations. One of the most important impediments in integrating In this study, we develop a sediment velocity model (SVM) that translates Vs30, the only proxy available to describe the sti ness of the near surface sediments in the Los Angeles basin, into a generic velocity profile suitable for use in wave propagation-based ground motion models. We speci cally develop a Vs30-dependent shear wave velocity model (previously referred to as Geotechnical Layer or GTL), based on the statistics of nearly a thousand measured velocity pro les with Vs30 ranging from 150 m/s to 1000 m/s. We validate the model by comparing the site ampli cation factors of the measured pro les and the SVM. We lastly develop and demonstrate the implementation of a spatially correlated random realization algorithm, intended to populate the near surface of the 3D UCVM domain with our SVM. The next step of this work is to use the pro les to improve high-frequency predictions of 3D physics-based ground motion simulations; and to develop Vs30-dependent ampli cation factors for implementation in the SCEC broadband platform.
Intellectual Merit The intellectual merit of the project lies on the development of a sediment velocity model (SVM) that translates Vs30, the only proxy available to describe the stiffness of the near surface sediments in the Los Angeles basin, into a generic velocity profile suitable for use in wave propagation-based ground motion models. We speci cally develop a Vs30-dependent shear wave velocity model based on the statistics of nearly a thousand measured velocity pro les with Vs30 ranging from 150 m/s to 1000 m/s.
Broader Impacts The broader impacts lie in the possibilities that SVM opens for performing not only 3D linear viscoelastic wave propagation simulations but also using the Vs30-dependent velocity profiles to develop empirical amplification factors tailored to the site conditions in So CA and their statistics, on the basis of the statistics of the large dataset that has been used to develop SVM.
Exemplary Figure Figure 3