Creating a Control Fence

A control fence is a 2D polygon which limits the area of topographical transition between existing site data and site modifiers enclosed in the fence; it can be thought of as a “limit of construction.” Outside the fence, the site remains unchanged; within the fence, the site model is defined by the pads contained within the fence. A control fence can overlap another control fence, but cannot completely enclose another control fence. A control fence should not cross a pad or grader.

Control fences are created automatically around certain site modifiers, such as roads. Control fences can also be drawn with the Site Modifier tool, or by drawing a polyline and then selecting the Objects from Polyline command (see Creating Objects from Polylines).

 

To create a control fence:

1.	Click the Site Modifier tool from the Site Planning tool set.

2.	Draw the control fence.

If this is the first time the Site Modifier tool has been used, the Object Properties dialog box opens. Accept the defaults and click OK.

3.	In the Object Info palette, select Fence from the Config field.

4.	The proposed DTM requires updating to reflect the control fence modification. Select the site model and click Update from the Object Info palette.