DIGITIZATION AND INTEGRATION OF STRONG MOTION ACCELEROGRAMS

Procedures for the digitization and integration of Strong-Motion Accelerograms are presented. Operational instructions and digitizing procedures are described for the Electrak Data Tablet/Digitizer, the Benson-Lehner Chart Reader, and the Microfische Film Reader. Optical scanning using the Perkin-Elmer Microdensitometer is also considered; but photographic problems with some strong-Motion Records limit the use of an optical method for digitization. The Electrak method is considered superior to other methods; the Microfische method gives excellent expedient results when commercial digitizers are unavailable. The computer program developed by Dr. M.D. Trifunac, et.al., at the California Institute of Technology is the basis for the integration procedure. A detailed description of the program is included. It is found that long period errors introduced by the program methodology can seriously affect the accuracy of the resultant time-displacement history. Changes in the high pass filters are needed to correct for these long period errors. When long periods in the frequency range of the error frequencies are part of the strong-motion acceleration record, it may be impossible to guarantee the accuracy of the integrated time-displacement curve. The appendix of the report contains a full listing of the computer program for the CDC 6400 and IBM 360/370 computers. A User's Manual is also included. /Author/

• Corporate Authors:

  University of Arizona, Tucson

  Department of Civil Engineering
  Tucson, AZ  United States  85721-0072
• Authors:
  • Miklofsky, H A
  • Mancini, W B
• Publication Date: 1977-8

Media Info

• Features: Appendices; Figures; References;
• Pagination: 295 p.

Subject/Index Terms

• TRT Terms: Accelerographs; Computer programs; Digital computers; Earthquakes; Errors; Frequency (Electromagnetism); Manuals; Optical scanners
• Old TRIS Terms: Digital systems
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00168404
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-77- 92 Final Rpt., FCP 35A2-981
• Contract Numbers: FHWA P.O. 5-3-0190
• Files: TRIS
• Created Date: Mar 7 1978 12:00AM