Modeling a Sloping Trench with Perforated Pipe in HydroCAD

[mtisdelle]

I have a general question for all the HydroCAD experts out there. Trying to figure a way to model a sloping trench (perforated pipe and stone) allowing infiltration. Also, i need to back this up to a Board, so any supporting references would be greatly appreciated. I am assuning that the sloping trench will limit the amount of infiltration so standard infiltration calculations will not apply.

 

[psmart]

Assuming that you're modeling ponding in the trench (rather than conveyance):

To model the storage in a rectangular trench, try the "pipe storage" option with a "Box" shape. This will let you set the trench slope. Remember to set the voids according to the trench slope.

Now you can define the storage in the perforated pipe, again using the "Pipe storage" option. Set the embedding so the pipe is embedded in the trench. Leave the voids at 100%, since this is the interior of the perf pipe.

As for exfiltration, I don't understand your question: you're trying to "allow exfiltration" but "standard exfiltration calculations do not apply"?? What are you trying to do? For exfiltration help please see

http://www.hydrocad.net/exfilt.htm

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[psmart]

That should have been: Set the trench voids according to the stone backfill.

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[mtisdelle]

Thank you so much. Poor choice of woods regarding the infiltration. What i met to say was infiltration modeling is rather simple when you have a flat bottom basin but get a little more unique in a sloping situation but the way you described it the complications of the calculations are done "behind the scenes" by HydroCAD. Thanks so much!