SEISMIC ACCELERATION COEFFICIENTS FOR MEMPHIS, SHELBY COUNTY, TENNESSEE

The objectives of this research are to generate bedrock motions for the study area and to estimate surface ground motion parameters from the bedrock motions, using wave propagation concepts. This approach is appropriate because the geologic features of the area include a deep soil layer. The results of the project are a set of maps for the design of bridges giving the spatial variation of peak ground acceleration and acceleration response spectrum values at certain frequencies for earthquake events with return periods of 100, 500, 1000, and 2500 years. The newly developed maps are recommended to be used as the minimum acceleration coefficients for designing bridges and their foundations in the metropolitan area of Memphis in lieu of AASHTO (American Association of State Highway and Transportation Officials) acceleration maps. The work breaks naturally into two parts. The first part is devoted to the estimation of bedrock accelerations, and the second to the conversion of the bedrock accelerations to surface accelerations. A very thorough and comprehensive literature search was performed to obtain all the necessary information about the geology and seismology of the area to be used in this study. The phase spectra of the generated earthquakes were matched with those of actual earthquakes which have occurred in stable continental regions with seismological and tectonic settings similar to those of the New Madrid seismic zone. In summary, a hybrid approach, using Brune amplitude spectra and observed phase spectra from earthquakes which occurred in similar stable continental regions, was used. The second part of the work concerned propagating the bedrock motions to the surface through the layered soil deposits. The program SHAKE was used to generate these motions. The primary information required by this program is the shear wave velocity. The data available are blow counts from standard penetration tests. A detailed procedure and verification for converting blow counts to shear wave velocity are provided.

  • Corporate Authors:

    University of Memphis

    Department of Civil Engineering
    Memphis, TN  United States  38152

    Tennessee Department of Transportation

    James K. Polk State Office Building, 505 Deaderick Street
    Nashville, TN  United States  37243

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Pezeshk, S
    • Chung, W Y
    • Chang, T S
    • Liu, Lei
    • Wei, B Z
  • Publication Date: 1996-6

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 287 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00725540
  • Record Type: Publication
  • Report/Paper Numbers: TNRES1036, Proj No. TNSPR-RES1036, Final Report
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Sep 9 1996 12:00AM