SUDA Tip: Shallow Nodes

Sometimes, when we model nodes in SUDA whose minimum depth is very shallow, we are surprised to see that the depth is not what we expected. For example, the inlet shown below should have a relatively small minimum depth of 2.33 ft.

SUDA minimum depth inlet 3d model

But, when we place it, the depth looks too large.  In fact, if we check the difference in top and invert elevations, we find that the depth has been set to 3.2808 ft (or 1.0 meters)

SUDA Element information minimum depth

We can edit the bottom elevation to correct the error, but if we have a lot of these it quickly becomes tedious.

SUDA edit minimum depth

This issue is caused by a bug (at least it seems like a bug to me) in the SUDA software.  Somewhere is a hard coded value that says to always use 1.0 meters as a minimum depth. Even though the value is 1.0 meters, it affects imperial units files as well, hence the 3.2808 depth of the shallow node above.

The quick fix offered by Bentley was to add a configuration variable while a more permanent fix is developed. Add the following to your workspace configuration to overcome this problem.  With the variable in place, all nodes will always default to the minimum depth which results from the combination of the top and bottom cells.


See other SUDA Tips:




“Scenario failed to compute: Review your data and try again.”

Best Practice for Headwall 3D Cells

Setting Node Orientation Relative to Centerline

Robert Garrett

Robert has over 25 years experience as a practicing engineer and is licensed in the State of Tennessee. After graduating from Tennessee Technological University, Robert worked for the Mississippi State Highway Department, Bridge Design Division. Then he spent 12 years with the Tennessee Department of Transportation in the Roadway Design Office and later served as Regional Manager in the Design Survey Office.From 2000 to 2006, Robert worked for Robert G Campbell and Associates in Knoxville, TN where responsibilities included roadway, site, and utilities design projects.Joining Bentley Systems in March 2006, Robert wrote specifications & documentation for software development. Duties included testing, customer feedback and ensuring the products met the needs of the civil engineering user base. He also developed training material for education both internally to Bentley and for outside organizations. He served as Product Manager for Utilities Products, including the new OpenRoads Subsurface Utilities Design and Analysis software. Robert also provided guidance and implementation services for new technologies.He is a frequent presenter and trainer at user conferences.

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