Catchments from object in Analyze gravity network

[raja_periketi]

I am trying to use Analyze gravity network tool in latest civil3d version. I created catchment areas from object tool to create the catchment are for the inlet. I added flow path to the catchment using object. But when I run the "Analyze gravity network" the tool is not calculating the flow from the catchment. 

I dont know if I am missing any steps. Any help will be greatly appreciated.

thanks

[fcernst]

Have you assigned a Reference Pipe Network Structure in the Catchment properties?

[raja_periketi · Accepted solution]

Hi Fred, thanks for the reply. I did assign inlet to the catchment.

I think I figured out the problem. I was using C(runoff coeff) value 1.0.

for some reason civil3d is not accepting that number. if I change the C value to 0.99 then the model is running successfully.

Thanks again

Raja

[fcernst]

Oh interesting..I just confirmed this behavior in 2020..

The software needs to be able to handle this as our storm frequency factors (C*Cf) can take C up to a maximum value of 1.0

@Charlie.Ogden

[xiaoming.fei]

Hi @fcernst and @raja_periketi ,

We are checking this problem, but fail to reproduce it. Following is the screencast for catchment with different TOC method, C(runoff coeff) value 1.0 works in both cases.

• TOC method - user defined https://autode.sk/31dQeyF
• TOC method - TR-55 https://autode.sk/2AeVSoh

Could you help to offer more information? Such as drawing, or record the problem by screencast

Thanks a lot.

[fcernst]

Yes, I still get this behavior.

One difference I see is that I am using the Tc from the Catchment... Then my Tributary flow panorama is grayed out...

[xiaoming.fei]

Yes, it is by-design behavior. In this case, all catchment parameters are from catchment properties, which are read only  in network details table. Since multiple catchments for one structure are supported in analysis, Runoff Coefficient is weighted value, and Time of Concentration is max one.

Catchments information for structure could be found in structure properties dialog.

[fcernst]

We still get the behavior of the Catchment dropping off when a coefficient of 1.0 is used in Catchment properties.

Again, you're showing that you're entering the coefficient through the AG editor...

[xiaoming.fei]

Hi @fcernst , I cannot catch your point very well, sorry for that. Could you help to record the issue you met by screencast? Then I could try to reproduce it.

[raja_periketi]

@xiaoming.fei I uploaded the screen cast

hopefully this explains the issue I have been having

[xiaoming.fei]

Hi @raja_periketi ,

Thanks for your screen cast, it is really helpful to focus the problem.

Your C3D is 2020.0, we have implemented some updates for Analyze Gravity Network in C3D 2020.1. In latest C3D, multiple catchments for one structure are supported. And catchment parameters in Network Details table are read-only if there is a catchment, which could be updated in catchment properties.

I also tried the case showed in Screencast in C3D 2020.0.

• Set all catchments Runoff Coefficient as 1.0
• Run Analysis
• It works

Could you help to attach the drawing? Then I could try that in C3D 2020.0 and C3D 2020.1

[raja_periketi]

@xiaoming.fei , please see attached. its an example autocad drawing from Autodesk (tutorial)

[fcernst]

Hi Xiaoming,

Here is my screencast. You will Pipe 57 not show up in the results.

https://autode.sk/31KsMJT

[xiaoming.fei]

Thanks @raja_periketi , I could reproduce the issue in your drawing in latest C3D build. We will check it and keep you update.

[xiaoming.fei]

Thanks @fcernst , It looks like flow is zero in Pipe 57. It could also be reproduced in Raja's drawing that catchment flow = 0 when Runoff Coefficient is 1.0. We will check it and keep you update.

[fcernst]

"..It looks like flow is zero in Pipe 57.."

To be more accurate in order to resolve the issue, you need to understand the Pipe does not appear in the Results at all...

[xiaoming.fei]

Yes. Since there is no flow in pipe, this pipe won't be listed in results table if "Resize pipes and reset inverts" is not selected in analysis.

[fcernst]

The flow shouldn't be zero, and even if it was it should still show up in the Results, not simply go missing..

This is the behavior we need..to see all pipes in the results.

[xiaoming.fei]

Hi @fcernst and @raja_periketi 

We have fixed this issue, you can get the fix in C3D 2020 update 2. Thanks again for your feedback.

Best Regards,

Felix

[fcernst]

Thanks Felix... I really appreciate your responsiveness to this issue. 

Looking forward to the update. 

Best, 

Fred