As shown in ORE-Report D 105/RP 1, many metal bridges must be regarded as considerable noise sources. The study of the possible reduction of noise radiated by such bridges led to the concept of noise-insulating encasements. However, it will never be possible to push this encasement so far that the bridge and the trains on it are fully enclosed as in tunnels. This leads to a through-shaped structure, open on top. The noise reduction afforded by such a structure is naturally limited by the noise emanating from the open part. In calculating the airborne sound insulation values obtain- able for these structures, this limitation should be taken into account. It become apparent that insufficient bases were available for the calculation of sound propagated across obstacles. Since any evaluation of the efficiency of encased bridge structures must be based on these principles, the ORE Specialists Committee D 105 considered the investigation in question indispensable. In order to limit the costs of the tests, the measurements were taken in open track and not on specially-equipped bridges and, as far as possible, with existing sound-propagation obstacles. This report shows that useful methods are available for predetermining the efficiency of sound-progagating obstacles. The results of these calculations can be used both for the study of problems of sound propagation in open track and for those concerning encasing bridge structures. Using the methods described, the constructional problems peculiar to the use of encased structures as sound- insulating elements on bridges can best be dealt with by practical tests.

  • Supplemental Notes:
    • Restrictions on the use of this document are contained in the explanatory material.
  • Corporate Authors:

    International Union of Railways

    Office of Research and Experiments
    Utrecht,   Netherlands 
  • Publication Date: 1969-4

Media Info

  • Features: Appendices; Figures; Photos; References;
  • Pagination: 13 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00052748
  • Record Type: Publication
  • Source Agency: International Union of Railways
  • Report/Paper Numbers: E82/RP 3/E
  • Files: TRIS
  • Created Date: May 14 1976 12:00AM