Define Lot Edge Grade Rules

This command establishes grade rules for use in elevating lot edges with respect to a reference 3D polyline such as a road edge or other feature that must remain at its established elevations. Elevating lot edges will create 3D linework along selected lot edges in the drawing and set them at their designated elevations based on the rules established by this command (see Elevate Lot Edges By Grade Rules for a more detailed explanation).

This routine defines the actions to take when elevating lot edges by grade rules, establishing three categories of slopes to create (normal, minimum, and maximum) in the two possible conditions that will occur (cut or fill), for the two edges of the lots being elevated (front edges and back edges). You may also establish intermediate grade breaks along the side lot lines by adding or editing additional grading rules in the middle windows. You define both cut and fill conditions in this routine, and the Elevate Lot Edges By Grade Rules command will use the appropriate condition based on whether the lot edge is in cut or fill at any given location with respect to a selected reference grade line such as a road edge or other feature.

Prompts

On execution, the routine prompts for a grade rules filename (.grr) to create if new, or select an existing .grr file. Once chosen, the following settings dialog will appear:

Options:
Slope Type:
Choose which type of slope to define, either percent, ratio, or vertical difference.
Normal slope: Set the desired slope to use in initial lot line elevation. This is the slope that is applied whenever you first execute Elevate Lot Lines By Grade Rules. Note that positive slope values are from the reference grade line up to the front lot line, negative slope values are from the reference grade line down, and may be set either positive or negative for either cut or fill conditions. This is useful to force positive drainage toward a roadway, even where the reference grade line is in a fill condition.
Min/Max Slope: These slope values are the limits for automatic adjustment in balancing the final grading of the lots in the RoadNET routines. The lot lines' slopes are adjusted to values between these two limits to achieve balanced cut and fill, and if balance is not achieved within these limits, then the entire site is raised or lowered to reach a balanced condition.
Side Line Grade Breaks: The middle windows in the dialog allow you to add, edit, or remove additional grade breaks along the side lot lines and are established at a distance from the previous grade break (either the front line or the previously defined break point), at a given slope (again, defined using percent, ration, or vertical difference).
Back Slopes: These values are for establishing the back lot lines' slopes from the last encountered grade break (either the front line, or intermediate grade breaks).
Back Lot Edge At Existing Ground: Selecting this option will make the back line slopes portion unavailable, and establish their elevations at the existing grade in their location. This will also prompt for selection of the existing surface model when executing the Elevate Lot Lines By Grade Rules routine to establish the required elevations along the back lot lines. Besides locating the back lot corners at the existing ground, this option will also drape the back lot edge on existing ground and add vertices into the back lot edge as needed to follow any undulations in the existing ground surface.

Pulldown Menu Location: 3D Data >> Elevate By Grade Rules
Keyboard Command: roadnet_grr
Prerequisite: None.