Working with Gradings

Overview

In BricsCAD, graded surfaces are created using the Create Grading tool.

Grading is a set of processes to maintain a base level for construction works or TIN surface design by defining a slope or adjusting the offset of a grading. For instance, creating parking areas, recreation reserves or road and railway designs.

Two projection methods Slope to surface and Offset to slope are supported:

  • Slope to surface needs an input entity (e.g., polyline, line, arc, circle), a surface and slope to grade the surface.
  • Offset to slope needs an input entity, offset and slope.

Graded surfaces are not editable with the TINEDIT command.

Procedure: Grading a surface to create a pond

  1. Open a drawing that has a topographical surface (1).
  2. Launch the GRADING command.
  3. Select the entity that defines the footprint area of your pond.
    Note: Before selecting the target surface you can change to slOpe/offset projection method which requires an input entity, offset and slope.
  4. Select the target surface.
  5. Define the slope of the grading.
    Note: Grading is attached to the input entity, and it is connected with the target surface. Moving the mouse in/out dynamically increases/decreases the slope of the grading.
    Note: If DYNMODE variable is set to 3, you can also input the slope angle directly from keyboard (4).
  6. Press ENTER to accept the slope of the grading.

Displaying the properties of a graded surface

The properties are displayed in the Properties panel after selecting the grading.
Grading type
Displays which projection method is used to grade the surface.
Target surface
Displays the handle number of the target surface.
The target surface of a grading can be changed by pressing the three points from the right side and selecting another target surface on the screen.
Cut slope
Displays the cut slope.
Fill Slope
Displays the cut slope.
Side
Controls on which side of the input entity the grading is drawn. Left or Right.
Infill
The internal area of entities is filled if this option is turned on. Valid for closed entities only (circle, closed polyline).
Boundary

Controls the boundary of the grading. When the grading boundary is on, that boundary is added as a hide boundary to the target surface.

The following images show when the grading boundary of the pond is off (5) and on (6). Based on the grading boundary, the net volume for the body of the pond is calculated and can be found in the properties panel (7).

Fill volume
Displays the fill volume for a body/shape limited with the target surface and graded surface.
Cut volume
Displays the cut volume for a body/shape limited with the target surface and graded surface.
Net volume
Displays the net volume for a body/shape.

Procedure: Grading a surface to create a platform

  1. Open a drawing that has a topographical surface (8).
  2. Launch the GRADING command.
  3. Select the entity that defines the footprint area of your platform (9).
    Note: Before selecting the target surface you can change to slOpe/offset projection method which requires an input entity, offset and slope.
  4. Select the target surface (10) to create a graded area.
  5. Define the slope of the grading.
    Note: Grading is attached to the input entity, and it is connected with the target surface. Moving the mouse in/out dynamically increases/decreases the slope of the grading.
    Note: If DYNMODE variable is set to 3, you can also input the slope angle directly from keyboard (11).
  6. Press ENTER to accept the slope of the grading.
    Note: You can easily move the platform that you created. Do this by using the manipulator on the entity from which you created the platform. You can move both horizontally and vertically.
    The grading will automatically be adapted to its surroundings.

About Balance Grading Volumes

The GRADINGBALANCE command allows you to balance cut and fill volumes within the specified tolerance. This is achieved by raising/lowering the elevation of the grading input entity and the result is grading that has a net volume around zero, depending on the set tolerance.

Procedure: Adjusting the elevation of a grading to balance cut and fill volumes

  1. Open a drawing that contains a TIN surface and a grading representing a building pad.
  2. Launch the GRADINGBALANCE command.
  3. Select the grading.
  4. Enter the tolerance in percent (1-100). 1 means that the difference between the cut and fill volume will be less than one percent and 100 means that the difference between the cut and fill volume will be less than 100 percent.
    In the Properties panel you can see that the cut and fill volumes are now balanced.