Pond Embankment Design
Pond Embankment Design
(OP)
I will have a stormwater pond constructed on gently sloping ground, bounded in part by a soil embankment, the other sides will be cut into existing ground. The interior and exterior slopes need to be between 3:1 and 4:1 to obtain the storage volume I need and the max slope for safety reasons (per our local drainage manual). The top of the berm is expected to be 6 feet wide at minimum. The max water depth will be about 4 feet, with one foot of freeboard.
How extensive of a design is typical for such a soil embankment? Or, following "standard guidelines" (of which there may be some??), is a detailed design not typically performed (e.g., flat slopes, wide crest, low berm). If a detailed design is standard practice,(which I'm suspecting it is) what are some of the more common standard design approaches?
(I work in a goverment office that is short on experienced engineers and long on managers...it provides nobody to bounce things off of.)
How extensive of a design is typical for such a soil embankment? Or, following "standard guidelines" (of which there may be some??), is a detailed design not typically performed (e.g., flat slopes, wide crest, low berm). If a detailed design is standard practice,(which I'm suspecting it is) what are some of the more common standard design approaches?
(I work in a goverment office that is short on experienced engineers and long on managers...it provides nobody to bounce things off of.)





RE: Pond Embankment Design
In my eperience working with the good glacial till soils in Chicago the quick check will show factors of saftey well over the F.S.'s given by the Corps of Engineers for all of the loading conditions. That may or may not be true else where.
RE: Pond Embankment Design
RE: Pond Embankment Design
http
It is listed under "Engineering Manuals"
www.SlideRuleEra.net
RE: Pond Embankment Design
The most important item to pay attention to is the outlet structure. Make sure it is big enough to pass a significant design storm, you only have 1 foot of freeboard. You may want to armor a slightly lower section to serve as an emergency spillway.
RE: Pond Embankment Design
Also, an emergency spillway is a must have for any basin. Size it to pass the complete 100-Year design flow and protect the spillway embankment (both sides and top) from erosion. This can be accomplished with riprap, concrete checker blocks, mechanical turf stabilization products (i.e. North American Green products or similar).
RE: Pond Embankment Design
RE: Pond Embankment Design
The embankment constructed using DOT Standard Specs for Select borrow, compacted to 95%. The embankment will have a key dug about 4ft below existing grade, 10 feet thick.
While I'm focused first on embankment safety, I also don't want go so far overboard being conservative that it costs 3x what it needs to. The 10ft thick "key" seems mighty big for this size embankment. The key size was based on design guidance from a stormwater manual based on designing storm ponds.
I'll take a look using the Taylor chart and see what FS I come up with.