Determination de la capacite hydraulique de lateraux de 75-mm de diametre pour le drainage souterrain
Authors: J. Gallichand, R.S. Broughton ct F. Papineau
Description: Seventy-five millimeter diameter pipes are not often used in Canada as subsurface drainage laterals mainly due to their hydraulic capacity being less than 100 mm pipes. The hydraulic behavior of lateral drains is adequately described by the non-uniform flow equa tion which results in outflow values 1.73 times those obtained with the uniform flow Manning equation. However, the outflow calculated with the non-uniform flow equation needs to be reduced to account for pipe deflection and silting. This paper studies the effects of pipe deflection and drain silting on flow reduction using a discrete form of the non-uniform flow equation. Results show that the flow is reduced to 93.5% of the maximum value calculated with the non-uniform flow equation due to pipe deflection only. The combined effect of deflection and allowance for silting resulted in outflows reduced to about 85% of the maximum value when guidelines on departure from design pipe grade used in Canada are respected. A flow reduction factor of 80%, to be applied to the non-unifom flow equation, appears sufficient and would result in outflows and lateral lengths 1.38 times those calculated with the unifom flow Manning equation.
Citation: J. Gallichand, R.S. Broughton ct F. Papineau 1992. DETERMINATION DE LA CAPACITE HYDRAULIQUE DE LATERAUX DE 75-MM DE
DIAMETRE POUR LE DRAINAGE SOUTERRAIN. Canadian Agricultural Engineering 34(1):1-6.
Publisher: Canadian Society for Bioengineering
Language 1: en
Rights: Canadian Society for Bioengineering