Create grading/feature line with more dependencies

[Stefan.Wieser.ecoMAP]

Hi there

I have a special problem and found no way to solve it automatically. May someone out there has an idea....

I have a feature line with a grade of -5% (red line). Now i want to create another line (blue) which has a grade of -15%. The slope between the two lines should always be 1:1.5 (y:x) (66%).

I can split my red line in sections and calculate the offset manually to construct the blue line...but i want to have it exactly...and when possible FASTER than this method

Any ideas?

PS: For the context: The red line is the right side of a road and leads into the ground level of a building (garage). The building is on a hill and the blue line is the left side of a road and leads into the basement of the same building. The slope between cant be more than 66% (Earthwork) and the whole construction should as less area as possible.

[ianjchap]

Hi @Stefan.Wieser.ecoMAP, 

Two ways you can do this if I understand it right, you can use the Adjacent Elevation by Reference picking the Grade or Slope.

Alternatively, you could use a Stepped Offset of the red feature line using the 66% grade. Offset an arbitrary amount, as long as it extends past the blue line.

Then create a temp surface with the red and new line. Then get levels from surface for the blue line from the new surface.

[ChrisRS · Accepted solution]

I suggest that the solution is determined by the desired elevation at the garage along with the length and slope of the red baseline. The blue line slope is what it is and can be compared to the 15% limit.

I would use a grade to distance transition grading. The distance at the top = 0.01 (edit) and the distance at the bottom = H/0.66 Slope = -66%.

EDIT: Select Create Transition from the dropdown. Also note that the minimum distance is 0.01. This is close enough to 0.is 

Buttinski Bonus: It seems to me that this design could direct drainage into the garage. I suggest that the red baseline should slope at 5% from point A to point B and then up to Point C, at about 2%.

I would use two grading objects:

• A grade to distance transition from Point A, with distance = 0.01 (edit), to Point B, with distance = H/0.66, and slope = -66%
• A grade to distance from Point B to Point C with distance = H/0.66 and slope = -66%

[Stefan.Wieser.ecoMAP]

Thx. I gave it at try but it wont work. The Adjacent Elevation by Reference will only update the elevations of the blue line but not the geometry of the line. So all my verteces will be perfectly at a slope of 66% but the slope between the vertices will change to different values. It should be all -15%. I need to change elevations and place of the verctices at the same time.

Actually i do it as you suggest in your second paragraph. I make a temporary surface and than i create a line with exactly -15% along this surface. For this step i use an third party add-in.

[Stefan.Wieser.ecoMAP]

Thx. I gave it a try. But where could i find a "Grade to distance transition"? I only have a "Grade to distance". I can choose one value only...

About the drainage. The values -5% and -15% are completly made up. Both roads will have a side slope of 3%. All water will got to your Point B as you suggested and there will also be a small ditch at the blue line. But at this stage its all about volumes and areas.

And i wanted to explain my problem as plain as possible...but thanks for the thinking

[ChrisRS · Accepted solution]

You will find the Create Transition option on the Grading Creation Tools dropdown.
0.01 is the minimum acceptable distance. I think this is close enough to 0.

I edited the original post to include this information.

It was not my intent to critique your "design."
I usually write my posts to be useful to beginners as well.
You small ditch and driveway cross slope a good practice. 

[obulesub]

Hi @Stefan.Wieser.ecoMAP ,

Just checking in to see if the additional guidance you received helped you achieve the result you were looking for. If it did, please consider marking the reply that helped as the Accepted Solution so others with a similar question can find it more easily. If you're still working through it, feel free to share an update.
Thanks!

[Stefan.Wieser.ecoMAP]

Thx, I never noticed this option before. That makes things much easier.