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help with driveway corridor


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I have a project I am working on in which i have to do the grading for a house that is getting built on a hillside, I am not new to acad just don't do much in the actual grading area until recently and I am learning as i go.  My first question here has to do with a driveway that leads to the house and making the corridor correctly for it.  As you can see in the picture I have it all but the one south section, where it widens to the garage area.  My question is, do i have to create a separate alignment for that little blue curve (from house to my red line) in order for my corridor section to target that line? Or is there another way?


using the redline I have drawn in as a visual reference, my corridor is as follows
1. an assembly from garage to red line that only has road on left side

2. same assembly as above but copied for right side (this is the one i need to adjust)

3. from red line east, a two lane assembly that leads to the connecting road


If this doesnt make sense please let me know and I will try to provide better info, this will not be my last question on here for this project :)


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It is possible you may need to specify some kind of subassembly on the shoulder for the program to actually interpolate that tight angle as intended (Even if it just contains null values).  Then have the program re-create your corridor.  What is your asphalt thickness and pitch?


Are you getting error messages?

Edited by ammobake
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i am just using the basic road assembly for this as of right now.

I am not getting any areas that I can see, i took out the cooridor assembly for the portion i need to do just to make it easier to see.  basically i need to have it widen to the right till it hits the edge of the driveway. I remember doing this once a couple years ago for a "knuckle" in a road, i just cant remember if i had to create an alignment for it to target, so i was just seeing if someone knew a way to accomplish this before i started messing around with it.


Edited by sonnyamorales
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Ahhh that makes sense. 

I remembered about the standard road assemblies after I posted.

It's been a year and a half since I've worked in Civil3d lol.  I worked on a roads and highways design team for a firm in Anchorage. 


One option is an offset alignment.  In the properties for the offset alignment there is a parameter for the offset distance for one side or the other that can be fine tuned to meet your needs.

This can be used in cases where one side of the road is wider than the other and is usually a kind of "linear" offset of the alignment for a highway or street (if that makes sense).


But in your case it may be the best option.

When you compile the corridor, it should then follow that curvature to match what you are going for.


Another possible alternative would be using a shoulder extend subassembly that follows the slope grade out to the edge (using the same base, subbase and asphalt thickness as the assembly, if applicable).  That subassembly would daylight at the same slope as the assembly, resulting in that curled edge at the corner per your survey data - and a properly compiled corridor.



Edited by ammobake
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Thanks for info, I will try offset alignments and see how that goes. Also have to figure out how to create the retaining walls and have surface dobwhat I want lol. Hard learning this on an actual project hahah 

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I use a 3rd party add on to civ3d but have to solve stuff like this, I would suggest that you also change your Red alignment and move its end pt closer to the centre of the garage with a larger radius, for me I would have 3 alignments and we can set grade control from say the red alignment. This will also help a possible problem of doing something odd as your lower end goes into like a negative offset.


It will require a good contractor to build this have done a few like this. Need a good setout with level control. 




Almost forgot the 1st step would be a vehicle path check no good having a driveway like this if the vehicle can not actually turn into it. Check the tighter curve in particular. I have a vertical vehicle check program so would use that also doing various alignments across the driveway shape. Its also built in to the software I used.


Edited by BIGAL
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