Numerous Outfalls when inserting an STM file exported from Civil 3D

[Dino.Lustri]

I am simply taking a pipe network from Civil 3D, using the Output tab of the ribbon to export to an STM file. Then using SSA to import the STM file. When I look at the plan view, there are outfalls coming from each inlet?! Did I do something wrong in Civil 3D? Do I need to take it into Storm Sewers first and then into SSA? The STM file is attached, thanks in advance for anyones help.


Dino Lustri, P.E., P.S.
Dell M4300
4 gb Ram
Dual Core 2.4 ghz
Nvidia Quadro FX360M w/256mb
On Windows 7 64 bit (and that ladies and gentlemen is the key!)

[Anonymous]

Hydraflow has two possibilities for inlets on grade - Offsite flow (lost
flow), or connected to another inlet.

In your case, your inlets flow offsite which is why SSA creates
additional outlets. SSA will account for the water leaving the system
and needs the additional offsite outlets to have some continuity.

Your best bet is to properly re-direct the gutter flow from upstream to
the next inlet.

Matthew Anderson, PE


On 5/24/2010 3:25 PM, Dino.Lustri wrote:
> I am simply taking a pipe network from Civil 3D, using the Output tab
> of the ribbon to export to an STM file. Then using SSA to import the
> STM file. When I look at the plan view, there are outfalls coming from
> each inlet?! Did I do something wrong in Civil 3D? Do I need to take
> it into Storm Sewers first and then into SSA? The STM file is
> attached, thanks in advance for anyones help.
>
>
> Dino Lustri, P.E., P.S.
> Dell M4300
> 4 gb Ram
> Dual Core 2.4 ghz
> Nvidia Quadro FX360M w/256mb
> On Windows 7 64 bit (and that ladies and gentlemen is the key!)

[Dino.Lustri]

I brought it straight from Civil 3D. Is there anything in Civil 3D I can do to make it import better into SSA? Or is good practice to export from civil 3D to Storm Sewers and then into SSA?

[Charlie.Ogden]

No, there is no need nor benefit to actually bringing it into Storm Sewers first.

What Matt said regarding "In your case, your inlets flow offsite", isn't because of anything you set - that's just what Civil 3D sets.

New Civil 3D Pipe Network structures will default to a Bypass value of zero (offsite).
Also since there is no "on grade" or "on sag" setting in Civil 3D, one is assumed - so structures exporting to a Storm Sewers inlet type (based on Part Matching) are set to "on grade" and bypass is "offsite".

Then in SSA the "offsite" Outfalls are created with generic Bypass Links attached - this would be the case whether it comes straight from C3D or from Storm Sewers.


Charlie Ogden, PE

[Civil3DGroupies]

Hi....I've encountered a similar problem as well in a couple stm files in storm sewers 2010.

I'm not using SSA however.  I'm going from Civil 3d, export to storm sewers, open in storm sewers and have numerous outfalls, in locations of curb inlets. 

It normally happens at the most upstream curb inlet of the network, or in a location where I have three pipes coming together.....  any thoughts on what is causing the outfalls?

thanks.

[Matt.Anderson]

You need to watch the pipe flow direction in Civil 3d.  A structure in Civil 3d is allowed to have multiple pipes that leave it, however, Hydraflow can not handle that situation and it will create multiple outfalls to accommodate the problem.

[qs39]

Hi I am having the same issue,  the only difference is that i have inlets connecting to inlets

[wizengr]

Watch John Sayre's video titled "Civil 3D and SSA Workflow-Storm water Inlet and Pipe Design workflow". It demonstrated how you can re-connect the bypass link away from each outfall to the next inlet.

https://www.youtube.com/watch?v=keoEAUdKGs0&t=196s