1307 W Sunflower Ave - Soils Report

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FAULTING AND REGIONAL SEISMICITY No known active or potentially active faults are shown crossing the site on any recently published maps reviewed (Jennings, 1994). No Seismic Hazard or Earthquake Fault Zones have been identified to cross the subject property by the State of California. There are a number of fault zones in the southern California area which are considered active and will have an effect on the site in the form of moderate to strong ground shaking, should they be the source of an earthquake. These include, but are not limited to: the San Joaquin Hills faultzone, the San Andreas faultzone, the Newport-Inglewood and Elsinore- Whittier fault zones. The approximate locations of these and other major faults relative to the site are presented in Appendix D. The possibility of ground acceleration or shaking at the site may be considered as approximately similar to the southern California region as a whole. The San Joaquin Hills fault zone is located as close as approximately 3.9 kilometers from the site, and the Newport-Inglewood (L.A. Basin) is as close as 7.3 kilometers from the site. A probabilistic seismic hazard analysis was performed using the computer program FRISKSP Version 4.00 (Blake 2000a). The necessary input for such an analysis consists of (1) a source model incorporating known regional active faults, (2) a seismic activity and frequency magnitude relationship, and (3) an attenuation equation relating maximum horizontal ground acceleration, earthquake magnitude, and source-site distance. Major active and potentially active faults within approximately 100 kilometers of the project site were considered in this seismic risk analysis and modeled as linear sources. The probability of exceedance (%) of various levels of maximum horizontal ground acceleration (g) for exposure times of up to 100 years are presented in Appendix D. The average return periods (years) for various levels of maximum horizontal ground acceleration are also presented in Appendix D. The data is summarized for a 50 and 100 year design life in the table below. Detailed results are presented in Appendix D. Calculated Peak Probability of Ground Calculated Design Life Earthquake Exceedance Acceleration Return Period (years)Level (%)(g) (years) 100 Operating 50 0.18 144 100 Contingency 10 0.36 949 50 Operating 50 0.14 72 50 Contingency 10 0.27 475 The following seismic design parameters should be used to draw the Design Response Spectrum, per Chapter 16 of the 1997 UBC: Pacific Development Group 1307 West Sunflower Avenue, Santa Ana File:\serveriandree\4900\497681.foundshopctr W.O. 4976-Al-OC November 2,2005 Page 4 GeoSoils, Inc.