HR: 16:30h
AN: S34A-03    [Abstracts]
TI: Impact of a Large San Andreas Fault Earthquake on Tall Buildings in Southern California
AU: Krishnan, S
EM: krishnan@caltech.edu
AF: California Institute of Technology, Seismological Laboratory, 1200 E. California Blvd., MS 252-21, Pasadena, CA 91125 United States
AU: * Ji, C
EM: jichen@gps.caltech.edu
AF: California Institute of Technology, Seismological Laboratory, 1200 E. California Blvd., MS 252-21, Pasadena, CA 91125 United States
AU: Komatitsch, D
AF: Laboratoire d'Imagerie G‚ophysique FRE 2639 Universit‚ de Pau et des Pays de l'Adour, Bƒtiment IPRA - Avenue de l'Universit‚ BP 1155, Pau Cedex, 64013 France
AU: Tromp, J
EM: jtromp@gps.caltech.edu
AF: California Institute of Technology, Seismological Laboratory, 1200 E. California Blvd., MS 252-21, Pasadena, CA 91125 United States
AB: In 1857, an earthquake of magnitude 7.9 occurred on the San Andreas fault, starting at Parkfield and rupturing in a southeasterly direction for more than 300~km. Such a unilateral rupture produces significant directivity toward the San Fernando and Los Angeles basins. The strong shaking in the basins due to this earthquake would have had a significant long-period content (2--8~s). If such motions were to happen today, they could have a serious impact on tall buildings in Southern California. In order to study the effects of large San Andreas fault earthquakes on tall buildings in Southern California, we use the finite source of the magnitude 7.9 2001 Denali fault earthquake in Alaska and map it onto the San Andreas fault with the rupture originating at Parkfield and proceeding southward over a distance of 290~km. Using the SPECFEM3D spectral element seismic wave propagation code, we simulate a Denali-like earthquake on the San Andreas fault and compute ground motions at sites located on a grid with a 2.5--5.0~km spacing in the greater Southern California region. We subsequently analyze 3D structural models of an existing tall steel building designed in 1984 as well as one designed according to the current building code (Uniform Building Code, 1997) subjected to the computed ground motion. We use a sophisticated nonlinear building analysis program, FRAME3D, that has the ability to simulate damage in buildings due to three-component ground motion. We summarize the performance of these structural models on contour maps of carefully selected structural performance indices. This study could benefit the city in laying out emergency response strategies in the event of an earthquake on the San Andreas fault, in undertaking appropriate retrofit measures for tall buildings, and in formulating zoning regulations for new construction. In addition, the study would provide risk data associated with existing and new construction to insurance companies, real estate developers, and individual owners, so that they can make well-informed financial decisions.
UR: http://www.gps.caltech.edu/~jtromp/research/regional.html
DE: 7223 Seismic hazard assessment and prediction
DE: 7212 Earthquake ground motions and engineering
DE: 7215 Earthquake parameters
SC: Seismology [S]
MN: 2004 AGU Fall Meeting