Exfiltration/Embedded Storage
Exfiltration/Embedded Storage
(OP)
I am designing a system with chambers set in a pit on natural earth. I am backfilling 6 inches beyond the chambers with crushed stone. I am modelling the system as a detention pond with a parabolic arch embedded inside a prismatoid. The outlet for the pond/leaching pit is through discarded exfiltration only. The first line on the pond storage tab is a prismatiod. The second line is the parabolic arch and it is shown as inside #1. I am using 40% voids for the prismatoid storage.
My question is what do I use for the length and width on the prismatoid storage screen? If I use the area enclosed by the perimeter of the backfilled crushed stone, I am not getting credit for the open volume (100% voids) in the chambers.
My question is what do I use for the length and width on the prismatoid storage screen? If I use the area enclosed by the perimeter of the backfilled crushed stone, I am not getting credit for the open volume (100% voids) in the chambers.
RE: Exfiltration/Embedded Storage
RE: Exfiltration/Embedded Storage
The stone is not under the chambers but around the perimeter. The chambers are put in the pit on native soil and then backfilled with stone. I could place a layer of stone under the chambers but for now I just want to understand how to model the backfilled stone which extends 6 inches around the perimeter of the field.
RE: Exfiltration/Embedded Storage
Pond 1P: (new Pond)
[43] Hint: Has no inflow (Outflow=Zero)
Routing by Sim-Route method
Peak Elev= 0.00' @ 0.00 hrs Surf.Area= 0.000 ac Storage= 0.000 af
Plug-Flow detention time= (not calculated)
Center-of-Mass det. time= (not calculated)
Volume Invert Avail.Storage Storage Description
#1 50.00' 0.107 af 50.00'W x 100.00'L x 5.00'H Prismatoid
0.574 af Overall - 0.306 af Embedded = 0.268
#2 50.00' 0.306 af 60.0"W x 48.0"H x 5.00'L Parabolic Arch x 2
0.413 af Total Available Storage
RE: Exfiltration/Embedded Storage
All you need to do is give the dimmensions of the total volume that will contain the stone and chambers. Set the voids at 40%. This is volume #1 in TerryScan's example.
Then define the chambers as volume #2 and set "embed inside volume #1" Be sure to leave the chamber voids at 100%.
Now check the storage calculations in the pond summary. This will show the exact storage calculation, including the contribution from the stone and chambers.