Adding mesh level zones 

Step-by-step guide

Mesh level zones can be used to define zones that require ground level modification.

The ground level at each zone vertex is determined from the ground model used during the meshing process, or from user-defined values. This allows greater flexibility and for sloped surfaces to be defined.

Adjustments to zone vertex levels are applied, and mesh element elevations within the zone are calculated from the resulting surface instead of the ground model.

The method of adjustment is selected in the Polygons window, Mesh level zone tab, Type field, which has numerous options. Visit the InfoWorks ICM Help topic, Mesh Level Zones for more information about the available options.

Open a 3D view window for this example:

1. From the Windows toolbar, click New 3D network window.

The bridge and road deck have been cleaned from the ground model, which is common. As this represents an important flow path, the goal is to build it into the mesh.

Start by adding a new polygon object:

2. From the GeoPlan Tools toolbar, New Object Type combo box, select Polygon.
3. Click New Object.
4. Place a vertex at each corner where the ground model level is correct.

5. Add more vertices, if needed, to define a more complex profile.
6. In the New Polygon window, add an ID of Deck.
7. Set the Type to Mesh Level Zone.
8. Click OK.

To quickly add the road surface for a bridge into the mesh:

9. Open the Properties window for the new mesh level zone object.
10. Set the Type field to Specify.
11. Next to Vertices, click the Ellipsis (…) to open the Vertices table.

For the Specify type, elevations at mesh level zone vertices are set to a user defined value, obtained from the ground model, or interpolated from other zone vertices as specified. This allows for changing the topography of the mesh level zone, as individual vertex elevations can be adjusted.

12. In the Vertices table, click the Vertex elevation type column heading to select the column.
13. Right-click the column and select Set new value(s) for cell(s).
14. In this example, in the New Cell Value popup, set all the Vertex elevation type fields to Ground model.

This generates an interpolated surface between them. Additional elevation adjustments can also be made, if necessary.

Regenerate the mesh to include the changes from the mesh level zone:

15. From the Model menu, select Meshing, and then Mesh 2D zones.
16. Click OK.
17. Once complete, load the updated mesh.

The effect is best seen in 3D view:

18. From the Windows toolbar, click New 3D network window.

The 2D elements within the mesh level zone now have ground levels set from the interpolated levels to form a high-level road deck.

The next consideration for this model is whether flow should be allowed to pass under the road deck, which requires the use of a conduit 2D link.

If any changes are made to a mesh level zone after meshing the 2D zone, recalculate mesh elevations within the 2D zone. This can be done by resampling elevations for selected 2D zones.