Stair Grading

[PW27]

Anybody have any special tricks for grading a stairway?

I'm sure there are at least a couple of ways.

[Anonymous]

The best tool for stairways is probably the Stepped Offset feature line
command if you're using feature lines without grading.

Relative elevation if you're using grading. Remember that Civil 3D does not
like perfectly flat grading or vertical grading. For your riser, instead of
making it perfectly flat, give it a 0.5% or so grade.

Matt

[Anonymous]

Unless you are building a surface for presentation purposes you can get by
with just a sloped face that represents the grading up to the edge of the
stairway.

wrote in message news:5511171@discussion.autodesk.com...
Anybody have any special tricks for grading a stairway?

I'm sure there are at least a couple of ways.

[BrianHailey]

Doesn't like perfectly flat grading? This is the first I've heard of this. Do you have anything to back this statement up?

Ok, that sounded really harsh. I'm not trying to be critical or anything, I'm just really curious.

Brian

[PW27]

Sounds like the stepped offset is worth looking into. He's right about the flat grading. I tried projecting a flat slope and a slope of 0.001% and the program ignored it. I also had some trouble grading in 2 directions off a feature line.

[Anonymous]

If you need to show the stairs in a 3D exhibit, you can make a stair with 3D
faces then copy and combine it into a block. Grade the stair cases with flat
slopes and put the block on top, explode it and remove the unnecessary
stairs. It will cover the slope when shaded, rendered or hidden. I can't see
any advantage to modeling the stairs in the TIN.

"neilw" wrote in message
news:5511483@discussion.autodesk.com...
Unless you are building a surface for presentation purposes you can get by
with just a sloped face that represents the grading up to the edge of the
stairway.

wrote in message news:5511171@discussion.autodesk.com...
Anybody have any special tricks for grading a stairway?

I'm sure there are at least a couple of ways.

[Anonymous]

Brian Hailey wrote:
> Doesn't like perfectly flat grading? This is the first I've heard of
> this. Do you have anything to back this statement up?
>
> Ok, that sounded really harsh. I'm not trying to be critical or
> anything, I'm just really curious.

Whereas I have no absolute concrete proof, and have not conducted my
normal experiments in a lab with Bunsen burners and my trusty white lab
coat, I do know that I crash quite frequently with very flat
grading...I'll have to agree with Matt here.

--
Jason Hickey

Civil 3D 2007, SP3
Dell Precision M70
2 GIG RAM, 256 MB nVidia Quadro FX Go1400
Intel Centrino 2 gHz Processor

www.civil3d.com

[BrianHailey]

Thanks for the confirmation on this Jason. I'll have to remember this in the future.

Brian

[mmccall]

How about drawing in a couple of polylines to represent the front bottom edge of the first and second step. Set them to the proper elevations and start copying the second step using the end of the first step as the displacement point and then each previous step as the destination. Add these to your surface as wall type breaklines with a height of each step.

[Anonymous]

Yes you can do that, but what I was questioning is whether we really need to
put those stairs in the surface model? They will not be useful for grading
quantities and contours across stairs are relatively meaningless. As far as
I can see there is no advantage to building them into the TIN and thus it is
basically a waste of time, unless you only have a few stairs of course (we
tend to have many). If you do need to show them in an exhibit, it could be
done with 3D faces. That way you would not have the overhead of updating the
TIN every time the stairs change. Just move the 3D faces to the new location
or elevation and you are done.

wrote in message news:5513674@discussion.autodesk.com...
How about drawing in a couple of polylines to represent the front bottom
edge of the first and second step. Set them to the proper elevations and
start copying the second step using the end of the first step as the
displacement point and then each previous step as the destination. Add these
to your surface as wall type breaklines with a height of each step.

[mmccall]

I totally agree that defining a surface to that extend would not be something I would take my time to do. Just putting another modelling option out there. I personally would just grade it as a smooth slope a not worry about each step.


Hmm, I suppose one could also do it with a little corridor and a saw tooth looking profile. Again, not something I would take the time to do.

[dana.probert]

i am pretty sure the guys in JP's office (Harland, can you hear me?) graded a stairway on their pilot....

[jwedding]

Against all sane advice, but yes, they did. It was done with feature lines.

--
James Wedding, P.E.
Engineered Efficiency, Inc.
Civil 3D 2007
XP Tablet, SP2, 2GHz, 2G
www.eng-eff.com
www.civil3d.com

[Anonymous]

Hey hey
Nevermind it's true.
File that one under some people are An*l Retentive.
Not me I paint with a mop.
Thank the lord some of my users use a 2 hair brush.
Or curse them occasionally.
Have a good weekend guys.

[Hammer.john.j]

I know this is an old topic, but here in 2014 I'm just wondering anybody has a better way of doing this other than feature lines or faces?  thanks.

[AllenJessup]

No better way I know of. It all depends what you want from the stairs. When I have to do a wall for grading but don't have to worry about quantities. I make a separate surface, construct the wall from featurelines and add them to the new surface. Then I can label elevations and create points at the surface elevation.

There's no Create Steps routine in Civil 3D. If you need quantities then use the Alignment, Profile, Corridor suggestion.

Allen

[Hammer.john.j]

In my case, I'm working on existing ground.... fyi.

[robert06]

To build stairs from feature lines, every stair has to be in separate site.

Vertical feature lines can't be created.

What I wonder is that you cant really even edit feature lines in model view direction.

A decent stairs and retaining wall tool is badly missed in Civil.