SCEC Award Number 16165 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Incorporation of Local Site Effects in Broadband Simulations of Ground Motions: Case Study of the Wildlife Liquefaction Array and Garner Valley Downhole Array in Southern California
Investigator(s)
Name Organization
Ramin Motamed University of Nevada, Reno John Anderson University of Nevada, Reno
Other Participants
SCEC Priorities 6e SCEC Groups EEII, GMSV, GMP
Report Due Date 03/15/2017 Date Report Submitted 03/15/2017
Project Abstract
 The principle objective of this research is to explore the most efficient approach to incorporate local site effects in Broadband (BB) simulations of ground motions and include the nonlinear soil behavior in the overall response. The recorded data by a geotechnical downhole array in California is utilized to validate and evaluate the proposed approaches. The approach used is the Composite Source Model, where the local site properties are incorporated into the velocity model that is used to generate the Green’s function. The Green’s functions are subsequently convolved with subevent source time functions to generate synthetics that simulate the ground motions. The direct procedure is amenable to introducing an equivalent linear approach to modelling nonlinear site response in a context of waves arriving obliquely, not vertically, at the site.
Intellectual Merit The local site properties are incorporated into the velocity model that is used to generate the Green’s function used to generate synthetic ground motions. The direct procedure is amenable to introducing an equivalent linear approach to modelling nonlinear site response in a context of waves arriving obliquely, non-vertically, at the site.
Broader Impacts The project partially supported a Masters student at UNR. In addition, a poster was presented at the 2016 SCEC Annual Meeting.
Exemplary Figure Figure 4. Fourier spectral ratios (surface/downhole [100 m]) for vertical and non-vertical incidence of S-H waves. Note that the peak is shifted to a lower frequency for non-vertical incidence.