Curb Grading

[Anonymous]

I am trying to create a curb using the Grade to Distance procedure from a feature line that represents my asphalt limits. 

I would grade to distance 2' with 0% grade, then .01' with 5000% grade, then 0.5' with 0% grade to finish the curb.

However when I try and go this way the corners of the curb turn out to be curves (See attached image). Is there a setting I can change to make it stop doing this? I know I could use stepped offset but I want the curb and the grading from the top back of curb to extisting ground to all be dependent of my original asphalt limits feature line.

[KMercier_C3D]

Sadly, with grading elements you will always get that curve in the corner. 

[Anonymous]

I guess that is not a huge deal. Does the process I amtrying to do make sense to try and use?

[Anonymous]

A general planer surface that ecompasses your curbs is a common approac to assign curb elevations. Infills can also solve you challenge

[Neilw_05]

It would make sense if gradings would create mitered corners. Since they do not you are left with the choice of using gradings with arcs at the corners or using featurelines and having to manually synchronize the flowlines & curbs with the edge of pavement. Neither is an acceptable solution in my opinion. It's one reason why I don't use C3D.

[Anonymous]

If you use alignments for your curb lines (offset alignment for tc and sw) and design your grading using a general plane (or more). Surface profiles and auto FL will alway be dynamic to changes in your grading.

Its a work flow; maybe not for everyone or application, but for parking lot and site grading its the bomb

[Neilw_05]

How do you define the plane?

[Joe-Bouza]

As you would any other ; with all the tools available,

[Joe-Bouza]

FL, gradings , corridors. Find your control points build the plane(s), sample profile, gen FL from align and add to fg

[Anonymous]

Basically,I take Eric Chappels technique 1 step further by making the FL from surface profiles, that way when the dedsign plane is edited the site takes car of it self

[Neilw_05]

I understand the concept. I've experimented with it but I find it becomes a cumbersome workflow for site work where there are a lot of transitions going on. For every break in the curb or sidewalk (ie.at ramps) you have to make a new offset alignment. When each curb has a flowline face, back and sidewalk you compound the number of alignments 4 fold. These along with several other challenges can make the process quite tedious to set up and manage.

I am not belittling the concept as it is a workaround to the deficiencies in the grading tools, but since I have more efficient tools I don't find it to be practical alternative.

[Joe-Bouza]

Where is the tedium? The curbs have to be drawn anyway so draw them as alignments naming templates go a long way but what is it you feel you have to keep track of ? Offset alignments make more sense to me as opposed to offsetting polylines and reoffsetting upon revisions. Alignments are not just for station lines. Alignments and surface profile are probably the most robust tool in the box

So what are these more efficient tools you use? I'd like to hear more

[Anonymous]

Using offset alignments makes editing the tc and sidewalks an non-issue - they all move together, and a judiscous use of widenings handles transitions well. Ped-ramps; I grade a seperate surfaces and paste into the FG. For me, alignments add much more versitility

[Neilw_05]

As I said, the number of alignments can become very numerous even for a simple site when you consider all the transitions that typically occur. You have to sample the surfaces for each of those alignments. Then you have to create featurelines from each of those alignments. You have to create numerous draping surfaces depending on the complexity of a site. So a simple site having 50 alignments requires at least 150 steps. Compared to using gradings that is a huge difference in workflows. That doesn't even acount for having to manage all the naming conventions and digging through long lists to find what you want.

All of that would be unnecessary if a single enhancemnet were added to the grading tools.

As you know, I am usiing Power Civil.

[Joe-Bouza]

I don't quite get your hangup with the number of alignments to keep track of - you have the same number of polylines to keep track of. There is nothing to manage - they are simply used as your geometry.

I'm curious Neil, by your own words you don't use civil3d because of the inability of gradings to mitre a corner. What is  the  panacea  you currently use for a dynamic site grading model and why doesn't it have a vast market share of the industry?

I respectfully disagree with how you envision the the steps required in the workflow described. Note this is a FL grading WF.

Where are the 150 steps? Granted I have a slanted point of view but the righ column appears to have less work

[Neilw_05]

You are comparing the workflow using featurelines or polylines. I don't consider that an acceptable workflow at all. I am comparing the workflows with Gradings. If it weren't for the deficiencies in gradings we would have a much simpler workflow.

Power Civil provides dynamic modeling with many superior tools vs. C3D as far as grading goes. As to why it doesn't have greater market share, I can only speculate that alot of it has to do with their marketing strategy along with their lack of resources to develop their products in a timely manner. Part of that is due to their policy of maintaining interoperabilty, something Autodesk has little concern for. They are quite shrewd in their changing the DWG format every 3 years and their new subscription policy that essentially forces users to subscribe.

I am not implying that Power Civil is a better solution for everyone but I find it is much easier for building and editing site models vs. C3D.

[Joe-Bouza]

I thought of that. Agreed. C3d lacks parametric linking of grading features

So how does PC handle the mitre?
Does it only run on microstation?

[Neilw_05]

Power Civil is a standalone app that includes the Microstation CAD engine. I don't think there are any modules that run on AutoCAD.

I'll post something that shows how it handles miters when I get some free time.

[Neilw_05]

Here is a screen recording showing how to apply different curb and sidewalks to a graphic element in Power Civil. The element represents edge of pavement. It has already been draped by centroid on a terrain to get it's elevation.

As the video progresses I am applying various curb and sidewalk combinations that I have defined and saved in a library to the edge of pavement. As you can see it is quite easy to change out the combinations. The software has no problem with the mitered corners.

In case you wonder, the curbs are dynamic to changes to the edge of pavement, both horizontally and vertically.

http://screencast.com/t/zlJvsTAOV9ga

[Joe-Bouza]

Looks good!