Spillway filter design
Spillway filter design
(OP)
I am working on the redesign of a spillway for a small embankment dam. The existing spillway leaked causing errosion of the underlying silty clay soils. I am currently designing a filter for below the new concrete spillway. Does anyone have any suggestions based on experience or any good references? Any comments would be appreciated.
RE: Spillway filter design
DEPARTMENT OF THE ARMY U.S. ARMY CORPS OF ENGINEERS
CEGS-02620 (August 1997)
In order to minimize the migration of fines into the coarser material while maintaining adequate permeability, the following criteria should be met:
All soils (except clays without a sand or silt fraction):
(15 percent size of drainage or filter material)/(85 percent size of material to be drained) = 5 (max)
(50 percent size of drainage or filter material)/(50 percent size of material to be drained) = 25 (max)
(15 percent size of drainage or filter material)/(85 percent size of material to be drained) = 5 (max)
(15 percent size of drainage or filter material = 0.4 (max)
All Soils
(15 percent size of drainage or filter material)/(15 percent size of material to be drained) = 5 (min)
for slotted/perforated subdrain pipes:
(50 percent size of drainage or filter material)/(slot width) = 1.2 (min)
(50 percent size of drainage or filter material)/(hole diameter) = 1.0 (min)
Additional information can be found in USACOE TM 5-820-2.
RE: Spillway filter design
RE: Spillway filter design