Rural intersection: grading behind curb and gutter with feature lines

Total video time: 14:28

Last updated: 2020-10-26

What we will look at now are the several control options you have over the corridor. We have shown the minimum for design and now we are going to look at some tools and workflows for different design situations. Instead of being tied to make adjustments to targets at curb return where daylight is added you may choose to create feature lines to the area behind the curb return. This process will add a lot of flexibility on how to edit and control the graded area, but it does come with a lot of manual control.

Exercise files: rurl-int-dsn-srfc-edit-03-end-data-c3d16.zip

Start with: 12345678\Design\Corridors\Crdr-25-4thAve.dwg

rurl-int-grdg-bhnd-cg-fl-01.mp4 6:34

Starting in the SW quadrant there is a big gap in the surface area. We will add in a manual feature line to build a surface in this area which will then be pasted into the refinement surface further down the project.

  1. Home tab > Create Design > Feature Line> Create Feature Line
  2. Change the layer to P_CRDR-Base

  3. Select the daylight_sub feature line just outside the back of curb and gutter it will inherit the elevation of that point

  4. Select the same feature line on the far side of quadrant

  5. Enter to Specify elevation
  6. Insert a PI somewhere along the middle- it can be adjusted later
  7. Enter to specify elevation
  8. Select Free curve fillet between two entities or Radius if you know the radius

  9. Adjust the grips to get it to match the back of curb closely- it will not be tangent anymore

  10. Save to use for the next exercise

Exercise files: Contiue with previous data set or start with: rurl-int-dsn-srfc-edit-03-end-data-c3d16.zip

Start with 12345678\Design\Corridors\Crdr-25-4thAve.dwg

rurl-int-grdg-bhnd-cg-fl-02.mp4 2:46

  1. Home tab > Create Design > Feature Line> Create Feature Line
  2. Set lalyer to P_Crdr-Base

  3. Select the Ditch_In feature line it will inherit the elevation of that point

  4. Select the same feature line on the far side of quadrant

  5. Enter to Specify elevation
  6. Insert a PI somewhere along the middle- it can be adjusted later
  7. Enter to specify elevation
  8. Select Free curve fillet between two entities or Radius if you know the radius

  9. Adjust the grips to get it to match the other feature line

  10. Repeat for the Daylight Feature Line

    Requirement: Because this is a daylight feature line we need to go through an extra step to make sure it drapes over the ground surface

  11. Select the feature line

  12. Edit elevations tab > Elevations from surface

  13. Select Existing Surface

  14. Insert intermediate grade break points > yes

  15. OK > Escape

Info: We need to add one more feature line along the corridor. This one needs to be based off the corridor so if there are any changes to the corridor it will react with it.

  1. Left click the outside corridor line > Create Feature Line from Corridor

  2. Layer > P_Crdr-Base

  3. No Smoothing

    Tip: In many cases smoothing works great but it does change the elevation slightly and will create little holes in the surface.

  4. OK > Escape

  5. When you hover over it you can see it is identified as an Auto Corridor Feature Line

  6. Save for use in the next exercise

Exercise files: Continue with previous data set or start with: rurl-int-dsn-srfc-edit-03-end-data-c3d16.zip

Start with 12345678\Design\Corridors\Crdr-25-4thAve.dwg

rurl-int-grdg-bhnd-cg-fl-03.mp4 5:08

Now we need to create a surface from the four feature lines.

  1. Home > Create Ground Data > Surfaces > Create Surface
  2. Name in Grdg-Int-SW-Quad
  3. Change style to Contours 2' Major:0.5'Minor

  4. OK

  5. Prospector > Surfaces > Grdg-Int-SW-Quad > Definitions > right click Breaklines > Add
  6. Type > Standard
  7. Weeding > yes > 5.00'
  8. Supplementing > 10.0'

  9. Mid-ordinate distance > 0.125

    Info: The supplementing factor can never be less than the Weeding factor as they have opposite functions. The mid-ordinate distance should be low because it is a curve but if you get too low it could cause excessive computing time.

  10. Select the lines being careful to select the Auto Corridor Feature Line

  11. OK

  12. Change the surface style to P_Triangles and you can see triangles that should not be part of that surface

  13. Highlight surface > Edit Surface > Delete Line

  14. Select all the lines outside the surface > Enter > Escape

  15. Save > Create Data Shortcuts

Info: This will be pasted into the refinement surface

  1. Design > Surfaces folder > Srfc-Rfnt-All-Datum.dwg > Open
  2. Data Shortcuts > right click Grdg-Int-SW-Quad > Create Reference
  3. Project > Surfaces > Rfnt-Int-All-Datum > Definition > right click edits > Paste surface > Select Grdg-Int-SW-Quad

  4. OK