Título del libro: 8th Us National Conference On Earthquake Engineering 2006
Título del capítulo: Numerical simulation of basin effects on long-period ground motion
LEONARDO RAMIREZ GUZMAN;
Autores externos:
Idioma:
Año de publicación:
2006
Palabras clave:
1-D models; 3D seismic; Basin depth; Basin effects; Fault geometry; Fault model; Finite difference; Finite element codes; Ground motions; Ground-motion simulation; Iso surface; Long-period structure; Los Angeles Basin; Nonlinear deformations; Predictor variables; Reference models; S velocity; Scenario earthquakes; Scenario simulations; Southern California; Spectral acceleration; Synthetic-time; Time history; Velocity model; Civil engineering; Earthquakes; Engineering geology; Motion estimation; Three dimensional computer graphics; Three dimensional
Resumen:
We simulate long-period (0-0.5 Hz) ground motion time histories for a suite of sixty scenario earthquakes (Mw 6.3 to Mw 7.1) within the Los Angeles basin region. Fault geometries are based upon the Southern California (SCEC) Community Fault Model, and 3D seismic velocity structure is based upon the SCEC Community Velocity Model. The ground motion simulations are done using 5 different 3D finite difference and finite element codes, and we perform numerous cross-check calculations to insure consistency among these codes. The nearly 300,000 synthetic time histories from the scenario simulations provide a resource for ground motion estimation and engineering studies of large, longperiod structures, or smaller structures undergoing large, nonlinear deformations. By normalizing spectral accelerations to those from simulations performed for reference hard-rock models, we characterize the source-averaged effect of basin depth on spectral acceleration. For this purpose, we use depth (D) to the 1.5 km/s S velocity isosurface as the predictor variable. The resulting mean basin-depth effect is period dependent, and both smoother (as a function of period and depth) and higher in amplitude than predictions from local 1D models. The main requirement for the use of the results in construction of attenuation relationships is determining the extent to which the basin effect, as defined and quantified in this study, is already accounted for implicitly in existing attenuation relationships, through (1) departures of the average "rock" site from our idealized reference model, and (2) correlation of basin depth with other predictor variables (such as Vs 30).
Entidades citadas de la UNAM:
ISBN:
9781615670444
Editorial:
Tipo de producto:
Conference Paper
