Applies To
	Product(s):	StormCAD, SewerCAD, SewerGEMS, CivilStorm
	Version(s):	08.11.03.77
	Area:	Output and Reporting
	Original Author:	Mark Pachlhofer, Bentley Technical Support Group

Problem

When validating or computing a model using the GVF-Rational (StormCAD) or GVF-Convex (SewerCAD) solver, the following user notification is generated: 

"Structure and pipe inverts do not agree with selected benching type" 

Background

This notification means that the inverts of the pipes at the manhole do not make sense for the selected benching type. For example, say you have the manhole benching method set to "flat". This assumes that the downstream pipe invert should be equal to the manhole invert. If they're not, you'll get that user notification that should suggest that you either need to correct the pipe/manhole invert or use the correct benching method.

In another example, say you have the benching method set to "depressed". In this case, the downstream invert is assumed to be above the manhole invert.

In the diagram below, which is from the help document titled "Correction for Benching", you can see what each benching method looks like:

Note that the benching method is selected in the node (manhole, catch basin) properties, when using the HEC-22 structure loss method.

Solution

Option 1 - Check your upstream and downstream pipe inverts for the node referenced

1. Double click on the upstream/downstream pipe from the referenced node to bring up the properties

2. Check and correct the start node and stop node in the "General" section of the properties as well as the start and stop inverts in  "Physical" section of the properties. Refer to the invert of the node in question.

Option 2 - Change the benching method for the node referenced

1. Double click on the node referenced in the message to bring up the properties

2. Check the "Physical(Structure Losses)" section and set the HEC-22 Benching Method property appropriately.