INFRASOUND GENERATED BY A HIGHWAY BRIDGE

Some residents near a highway bridge in Kashiba-cho, Nara complained about noises of house fittings and physical effects that may have been caused by infrasound. Preliminary measurements revealed infrasound of 90 dB or more near the bridge. A series of measurements were thus made near the bridge to determine the source and it was found to be an eigen-oscillation of the bridge girder. The reasons are: (1) signature of bridge-girder oscillation is very similar to that of sound pressure beneath the bridge; and (2) distance-attenuation of sound pressure at 4.8Hz, which is the target frequency, is inversely proportional to the distance from the bridge suggesting the bridge girder to consist a dipole source, i.e. generation of positive and negative pressure on the upper and lower sides of the floor-slab of the girder or vice versa through bending oscillation of the girder. In this article the generation mechanism of infrasound is examined using existing data that are not necessarily perfect for the purpose of rigorous analysis. For the covering abstract see IRRD E104312.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0962207233
• Corporate Authors:

  Institute of Noise Control Engineering

  Iowa State University, 210 Marston Hall
  Ames, IA  United States  50011-2153
• Authors:
  • Kobayashi, Y
• Conference:
  • PROCEEDINGS OF INTERNOISE 99 - THE 1999 INTERNATIONAL CONGRESS ON NOISE CONTROL ENGINEERING HELD IN FORT LAUDERDALE, FLORIDA, USA, 6-8 DECEMBER 1999, VOLUME 1
• Publication Date: 1999

Language

• English

Media Info

• Features: References;
• Pagination: p. 329-34

Subject/Index Terms

• TRT Terms: Bridges; Highways; Infrasound; Mathematical models; Measurement
• ITRD Terms: 3455: Bridge; 2755: Highway; 6749: Infrasonic noise; 6473: Mathematical model; 6136: Measurement
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00790198
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0-9622072-3-3
• Files: ITRD
• Created Date: Apr 11 2000 12:00AM