I have a simple driveway corridor along a steep hillside. For cut, I would like to have a negative slope away from the shoulder edge. I have tried numerous approaches and all 'cut' reverts to positive. I searched and found no clear answer. It's such a short driveway, I can 'fake' it in, but I would like to calculate quantities. What is the answer? Why is this so complicated? Thanks.
Using 2012 sp1, 64bit, windows 7
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In the programmers terminology "cut" is always upwards, and there is no such thing as a negative cut slope.
How are you building this slope - grading objects or corridor?
There are several subassemblies that will allow you to force a downhill slope from the road shoulder to a specified distance or elevation, then back up to the ground surface. A drawing or sketch showing what you already have and what you're trying to achieve would be helpful.
Well, I tried that. It will work if I specify only cut, but it won't display. See attached. I just need to specify a simple bench cut. Suggestions?
LinkSlopeToSurface may not be the appropriate choice for this situation. If you want to enforce a downhill slope to a surface which is a cut situation then there is a workaround using the DaylightGeneral sub to do this.
DaylightGeneral builds a series of temporary links out to a test point, which is normally at the outside corner of a ditch. If this point is in cut then it continues to build the rest of the ditch and daylight. If any part of the temporary links are in cut, but the test point is in fill then it works backward along the links until it finds an intersection with the surface and daylights there. For your scenario I would put the test point at the end of the first temporary link, and make that link at the correct slope but very long so that the test point would always end up in fill.
It may not be overly apparent - but if you use LinkSlopetoSurface and in Subassembly Properties, specify Fill Only, the Subassembly will project a "downward" slope, in a Cut condition.
I've attached an image that shows something similar. Note the Subassembly Properties (Fill Only) and how this parameter is interpreted in the Corridor Section Editor.
Hope this helps.
The default daylight subassemblies have conditions that do not allow negative slope values. Using Subassembly Composer you can create your own daylight subassembly that does not have any restrictions on slope value.
Attached is an example subassembly that I use for these conditions.