MONITORING AND RECORDING WIND VELOCITIES, DIRECTIONS AND EFFECTS AT LONG SPAN BRIDGE SITES

The report describes instrumentation, consisting of a digital recording system and an array of sensors, in place at a suspension bridge site in Sitka, Alaska, to measure bridge motions in response to wind and seismic forces. Three-axis anemometers measure winds, servo accelerometers measure bridge motions, and a strong-motion accelerograph measures seismic activity. The system is activated automatically by strong winds, bridge motions, or seismic events, and data are recorded on digital magnetic tape for subsequent processing. Wind data recorded during a tropical storm while the system was installed in Newport, Rhode Island were processed during the year covered by the report. Time-based data were transformed to frequency spectra using various processing techniques and the effects of the techniques are compared. Decimation, detrending, windowing, and spectral smoothing are discussed. /FHWA/

• Supplemental Notes:
  • Sponsored by DOT and FHWA.
• Corporate Authors:

  Systems Technology Associates, Incorporated

  2990 Telestar Court
  Falls Church, VA  United States  22042
• Authors:
  • Gerhardt
  • NELSON, D D
• Publication Date: 1975-8

Media Info

• Pagination: 64 p.

Subject/Index Terms

• TRT Terms: Data collection; Elastic waves; Information processing; Instrumentation; Long span bridges; Molecular structure; Suspension bridges; Thin films; Velocity; Wind
• Old TRIS Terms: Data recording; Molecular films; Wind velocity
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00144119
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: FHWA-RD-76- 10 Ann. Rpt., FCP 35A1-012
• Contract Numbers: DOT-FH-11-7769
• Files: TRIS, USDOT
• Created Date: Dec 15 1976 12:00AM