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Workflow Processes:

• Planar Parking Lot

  To grade parking features along a specified grading plane, a setup surface can be used. Using a single control elevation and slope vector, you can model a grading plane for a given cross slope. In this process a single grading control feature line is used to set the control elevation and set the parking cross slope. Gradings are added to both sides of the grading control feature line to form a grading plane, resulting in a planar setup surface. The proposed CAD geometry is then converted to feature lines and elevated to the setup surface. After the grading has been applied to the proposed features, a new surface is created from the Breaklines. This process leverages object relationships to maintain a dynamic proposed grading model will automatically update if the elevation control and/or parking cross slopes need to be adjusted.
  NOTES:
  This workflow closely replicates the tasks and steps performed in the course Grade Parking Features.

• Planar Culdesac

  To grade a planar culdesac, a setup surface can be used. Using a single control elevation and slope vector, you can model a grading plane for a given cross slope. In this process a single grading control feature line is used to set the control elevation and set the culdesac cross slope. A Grading is added to form a grading plane, resulting in a planar setup surface. The culdesac flange profile is then elevated to the setup surface and incorporated into the adjoining corridor model. Transition profiles will then be used, levering the setup surfaces, to blend the corridor and culdesac region. The resulting grading model will mostly be dynamic, and can further be edited and refined to achieve the final grading design.
  NOTES:
  This workflow closely replicates the tasks and steps performed in the course Grade Planar Culdesac.

  For his workflow the corridor model has already been started and includes a baseline region for the transition grading. This is required so the transition grading can use a different baseline, than the previous baseline. If you are following this workflow, add the transition baseline and region to the corridor model before adding the culdesac grading. In the illustration below, the middle baseline is where the transition grading will be applied.

  Planar_Culdesac_001

• Superelevated Intersection

  Grading a superelevated intersection in Civil 3D can present a challenge as superelevated cross slopes from the primary road need to transition/blend in with standard pavement cross slopes of the secondary road. A Civil 3D intersection object can be used to perform this grading, but additional inputs are required to control the lane elevations through the intersection. One approach that you can take to create these inputs is to use a Setup Surface. The setup surface is modeled from a normal road corridor, only the top surface from the corridor is needed to acquire edge of pavement elevations. The resulting surface profiles from the setup surface can then be used as lane slope profiles in the intersection model.

  To create the Setup Surface for the primary road, a Setup Assembly and Setup Corridor are needed. The Setup Assembly needs to have superelevation capabilities and yield the same top surface elevations as the full design assembly. The Setup Assembly will be used in the Setup Corridor to superelevate the travel lanes through the intersection and create the Setup Surface. These “lightweight” setup features will need to remain in the drawing file and will be dynamic link with the proposed intersection grading.

  This process models the pavement transitions between a primary road in superelevation and a secondary road with standard pavement cross slopes. Curb and Shoulder grading will not be included in this workflow, but similar steps can be used to blend these grades through the curve returns.

  The end result that is targeted from this workflow is a graded intersection model, similar to that illustrated here.

  Superelevated_Inters_001
  NOTES:
  This workflow closely replicates the tasks and steps performed in the course Grade Superelevated Intersection.