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SSA Max HGL doesn't match between profile plot and table

12 REPLIES 12
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Message 1 of 13
jmatthei
2345 Views, 12 Replies

SSA Max HGL doesn't match between profile plot and table

It's my first time using SSA, and I'm finding the program definitely has it's share of quirks - I'm not sure I'm sold on it yet.

 

I had finally created a network and storm that I thought was working properly (using TR-20 routing with an SCS II storm), until I took a closer look at the profile outputs - and noticed that the graphed Max HGL line does not match the Max HGL listed in the table below.  The difference was 856.2 on the graph and 858.01 on the table at one my structures, for example.  Does anyone know why this is?  Which is incorrect?  How to fix it?

 

The ability to import pipe networks is nice in SSA, but if the output data is always this wacky I may have to go give up on SSA and go back to using Hydrocad.

 

--Jeremy

12 REPLIES 12
Message 2 of 13
Matt.Anderson
in reply to: jmatthei

Jeremy -

 

The report will be the maximum HGL over the time of the analysis based on the time steps in the reporting step.

 

The profile will show the HGL at the current time.  I would suggest looking at the Output animation.  In other words - the profile is showing a time-variable HGL and the report is showing you the maximum.

 

You can review each structures time-varying HGL in the time series plot as well.

 

 

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 3 of 13
jmatthei
in reply to: Matt.Anderson

Thanks.

 

I found out by trial and error it's actually more complicated than that - but I think I found the solution:

 

You need to be sure the "reporting" interval is the same as the "routing" interval.  I had 1-minute routing intervals but 10-minute reporting intervals.  The table was then showing the max HGL from the 1-minute interval, but the graph showed the max from the 10-minute interval.  Apparently the peak was midway between the two 10-minute intervals, so there was a substantial difference between the values.  After I made the reporting interval also 1-minute, the data aligns much better.

 

--Jeremy

Message 4 of 13
Matt.Anderson
in reply to: jmatthei

Jeremy -

 

Yes, that would also provide different answers.  By having the taken only ten-minute reporting interval, you are dismissing 9 possible other points within a 10-minute window that could show a peak.

 

That is why I answered originally with

"The report will be the maximum HGL over the time of the analysis based on the time steps in the reporting step."

 

Hope that helps.

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 5 of 13
jmatthei
in reply to: Matt.Anderson

Thanks.

 

Of course this leads to the question:  "Why even have two boxes for intervals if they must always be set the same?"  I was trying to reduce the raw data in a table, but I had hoped that the Max HGL would come from the routing data, not the reporting data.

 

May I also ask what routing-reporting interval you typically use?  Have you found a good balance between accuracy and computational speed?

 

Jeremy

Message 6 of 13
Matt.Anderson
in reply to: jmatthei

Jeremy -

 

There are two ways to answer that question;

 

1.)  Because we support EPA SWMM import/export which allows the variables to be different. 

2)  One isn't always seeking a design level [In model calibration we may have reported intervals that we are attempting to match, yet we want smoother hydraulic routing calculations,

 

What do I use? Depends on model size and method - rationals 1 min reporting / 30 sec routing;  SCS 5 min reporting/1 minute routing are typical. 

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 7 of 13
jmatthei
in reply to: Matt.Anderson

I'm so sad.  I had such high hopes for SSA.  It looked so amazing.

 

Unfortunately my last fix didn't fix everything.  Some nodes look OK, but others still have differences of several feet between the Max HGL shown on the graph and the Max HGL shown on the table.  I've matched routing and reporting times, and even looked at the reports per minute to compare them with the graphs per minute.  They are showing completely different values.  Why the tables are using a different formula from the graphs I don't know, but at least one of them is obviously wrong.

 

Oh well, I'm done alpha-testing the program.  It's broken.  I'm going to uninstall it from my system now.  Back to the old way.

 

Jeremy

Message 8 of 13
Matt.Anderson
in reply to: jmatthei

Jeremy -

 

That is a quick dismissal of the software.  Could you have missed something? Do you want help?

 

Have you opened a service request with Autodesk Support? They are there to help.

 

Have you posted your model here to the discussion group so that we can assist?

 

SSA contains a lot possible settings - from the profile plots to the routing time steps, to hydraulic modeling parameters.  It's hard to telll what is up with the model.

 

If you want, email me the file and I can take a look.  matt dot anderson at autodesk dot com

 

 

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 9 of 13
ncullen12
in reply to: Matt.Anderson

I have been having the same issue as Jeremy. I have looked at and matched reporting/routing intervals. I have attempted to replace the junction node 105 as well as replaced the connecting pipes. (also same issue with Jun-74)I have also tried different invert elevations and rim elevations with no luck. I hope that someone could please look at this model and see if you can fix this issue. Thank you and please see attached.

 

Please note - The forum does not allow me to attach my model. I get the warning that it does not support .spf file extensions. Ideas?

Message 10 of 13
wfberry
in reply to: ncullen12

Just rename the file to something different, i.e., use .txt in lieu of .spf and note the change.

 

Bill

 

Message 11 of 13
amarlerH9H6T
in reply to: jmatthei

hello- I am having the same issue.  However I have iterated about everything I could.  I even ran this in UD Sewer, a local Denver HGL analysis program that is a pain to use.   Remade the model, cut this leg from the entire network, exported from pipe networks....

 

The max hgl in the table is popping inlets.  

Using a tailwater and Hydrodynamic modeling

have iterated time steps, routing, and reporting. 

It was somewhat stable and then I updated the flows.

Flows are input as known flows. 

I think the pipes are large enough..

Any thoughts?  

 

I have uploaded the file if anyone can take a look  just change .txt. to .spf

 

-Alaina Marler, PE

 

 hgl profiles Page 001.pnghgl profiles Page 002.png

Tags (2)
Message 12 of 13
Grimes_MG
in reply to: amarlerH9H6T

SSA is just about the worst analysis software I have ever used. When I exported my pipe network, SSA decided to give some of the pipes a different Manning's "n" value than all the other similar type pipes in the network. It also made some of the conduits box culverts rather than circular conduits even though I did not have any non-circular pipes in my C3D pipe catalog.

 

I really do not like anything about SSA.

 

The Output Table interface is horrible. The input dialog boxes are a joke. The export of C3D networks and import to SSA crashed routinely. SSA renames my network elements so the output tables don't match my C3D plans. Garbage.

 

Autodesk's Civil 3D's "Hydrographs", "Express", "Storm Sewers" Launch Pad items all crash (even tried the fix posted on forms with no luck). They tried to jump into the game with Bentley but bought inferior software when they did.

 

Autodesk needs to completely re-code this POS extension. BENTLEY's/HEASTAD's WATERCAD, SEWERCAD, and STORMCAD are superior software programs.

 

Autodesk needs to incorporate the hydrology analysis tools INTO C3D rather than using supplemental software. Make it an extension within C3D not a export/import add-on feature.

Win7 (x64), EVGA 790i, 8GB RAM, EVGA 8800GT, 250 GB iSSHDD, & RAID 0/1
Tags (2)
Message 13 of 13
Turtlewallet
in reply to: jmatthei

I'm having the same issue. Except when using the SBUH Hydrology method, the option to change the reporting and the routing time steps is unavailable. Not sure what to do in this situation...

 

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