Tin volume surface not created correctly (C3D 2020)

[Anonymous]

Hi,

First time here. I've been through the forums but can't find the answer to my issue.

I'm modelling a dredged area in a seabed. I've created a grading group from a feature line then generated the surface from that. This surface works fine. On plan the flat dredged level is -13.0.

The grading is only three sides as the fourth side stops at the -13.0 contour.

When I create a volume surface my issues start, please see screenshots.

The volume dashboard reports just cut which is what I expect but the surface isn't correct.

It may well be my work flow.

1. Create a surafce bigger than I need then use MINIMUMDISTANCEBETWEENSURFACES to get the dredged outline.

2.Create a feature line from that polyline (explode 3Dpolyline and create a closed 2D polyline at -13.0)

3.Create the grading group then generate a surface.

All this works fine.

When I create a Tin volume surface using the SEABED SURFACE as the base then the Dredge surafce as a comparison, the surface builds itself up to the highest point.

Any help and work flow advice would be much apprecaited.

Regards,

Phil.

The Volume

[Anonymous]

I've now created a volume surafce but switched the surface order so I have a fill surface. This looks as I would expect.

[wfberry]

Why would you expect a fill surface in a dredging operation?

Bill

[Joe-Bouza]

Good question

[Anonymous]

Hi,

The fill test was purely to see what result I got, and it created the surface as I expected.  The volume of that surface is correct.

When I cut as it would be, I don't get a flat base to the surface at -13.0m. The back of the cut is -13.0m but it gradually increases level until it reaches 0.00m.