Performance of Pennsylvania Highway Drainage Inlets

by Arthur W. Brune, (M.ASCE), Assoc. Prof.; Dept. of Civ. Engrg., Lehigh Univ., Bethlehem, Pa.,
Peter P. Yee, Dept. of Environmental, Water Planning and Management Branch, Burlington, Ontario,
Erik Appel, Peter Dangsvej, Valby, Copenhagen, Denmark,
Walter H. Graf, (M.ASCE), Laboratoire D'Hydraulique, Ecole Polytechnique, Lausanne, Switzerland,

Serial Information: Journal of the Hydraulics Division, 1975, Vol. 101, Issue 12, Pg. 1519-1536

Document Type: Journal Paper


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 efficiencies 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.

Subject Headings: Hydraulic models | Highways and roads | Drainage | Inlets (waterway) | Slopes | Flow rates | Scale models | Water discharge | Pennsylvania | United States

Services: Buy this book/Buy this article


Return to search