The hydraulic performance of six gratings for the drainage inlets used by the Pennsylvania Department of Transportation were tested hydraulically using a scale ratio for the model: prototype of 1:2. The variables in the tests were the discharge rate, and the three slopes of swale, side, and longitudinal or grade, in order to determine the hydraulic efficiences at different rates of approach flow. The tests showed that the efficiency of a grating decreases with an increase in grade; the efficiency is a maximum with both side slopes being equal. The geometrical configuration of the grating did not affect the efficiency of a grating. Ponding of a grating at the bottom of a vertical curve occurred only under extremely high rates of flow. Installing a dike downstream from an inlet in a median increased the capacity markedly.

  • Corporate Authors:

    American Society of Civil Engineers

    345 East 47th Street
    New York, NY  United States  10017-2398
  • Authors:
    • Brune, A W
    • Graf, W H
    • Appel, E
    • Yee, P P
  • Publication Date: 1975-12

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 1519-36
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00129060
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #11801
  • Files: TRIS
  • Created Date: Mar 10 1976 12:00AM