Road Design Notes: June 2004 vs. January 2007

Over the holidays, I took the opportunity to clean out my old files. In one of my old planners, I found my notes from a road design I did in June of 2004. There were about 20 pages of diagrams, sketches, ideas and most of all- record keeping.

I still keep lots of notes about my thoughts, typical sections and trial runs these days, but a good chunk of the checklists and record keeping that I used to do has been replaced by tools inside Civil 3D.

I thought it might be fun to show you some of the ways I used to solve design problems in my notes, and how you might want to leverage Civil 3D to help you do the same tasks now.

Click more to see my original notes from June 2004 when I was using Land Desktop, and ideas on how I tackle those tasks now.

PROBLEM #1: LOCATION OF PVIs AND LOW POINTS IN PLAN

You get the land plan and road centerlines. You sketch in a vertical aligment. Chances are, your PVIs are not at even 100 ft stations, so you need to mark on plan where those PVIs fall so that you can do your design. It is also nice to know the elevation of the PVI. The thing that always screwed me up here was that since it was always a bit of a pain to redefine all of your vertical curves, I would wait until my design was almost in place before I made the vertical curves. So, when I put the vertical curves in, the location and elevation of the low points would change and potential mean I had some serious regrading to do. So, out comes the pencil and paper and calculator….

Now, I can set up alignment labels that reference the FG of my choice. It marks the location of the profile geometry points and their elevations (and lots of other things depending on how I set up the style). Now, I can have a visual check and save some paper and HB.

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PROBLEM #2: TRACKING STATIONS, ELEVATIONSÂ AND DESIGN INTENTÂ OF TRANSITIONS

I used to mark and makes notes on the locations coming around culdesacs, coming into intersections, changing road width, etc. Using my calculator and what I knew about my centerline elevation (and praying it didn’t have to change) I would usually take an 11X17 print out of my road and mark my calculations in red pen, then either make transitions in my road template, or use 3D polylines after the fact or, gasp, hand draw contours.

In my mind, building a corridor is a lot more intuitive than the Land Desktop/Civil Design road cross section tools. So now, I tackle each design knowing that my goal is to build a corridor that will produce a finished ground road surface with minimal babysitting. This means creating a model that is easy to edit and has all of the appropriate raw materials so that quick edits rebuild my corridor to reflect my design intent.

One of the tools that I leverage to assist with this process is a Station/Offset label that I have shown you before, but it has been so helpful to me that I wanted to mention it again. Also- keep in mind that this is just one example of when this concept can come in handy. Use your imagination to find ways to create labels that help you design and check your work.

For a primer on using reference text and expressions visit:

http://civil3drocks.blogspot.com/2006/08/using-expressions-and-references-to.html

http://www.civil4d.com/2006/11/using-if-statements-in-surface-label-expressions/

You can download a drawing that has a sample of an intersection design, as well as samples of these labels so you can tear them apart and see how they work.

http://www.civil4d.com/2006/11/another-intersection-sample-drawing/

PROBLEM #3: MAKING SURE THINGS MATCH UP NOW, AND AFTER REFINEMENT

Once I thought I had a really good vertical alignment in Land Desktop, I would find out that a few of my road centerlines didn’t match at their intersections. From here, the entire checklist had to be rechecked. Templates had to be rerun. Intersection grading had to be redone and my notes, sketches and calculator would be working overtime to make sure it all matched up. It was really easy to miss something.

Now, I have a Station/Offset Label with an alignment reference (for the intersecting alignment) and two profile references (for this alignment and the intersecting alignment). A quick scan of all of my intersections lets me know right away if one of my edits caused a mismatch. The same type of thing can be done with a Profile View label, or another thing I like to do is split my screen into two viewports and watch the Station/Offset label update with my edits.

You can download a drawing that has a sample of an intersection design, as well as samples of these labels so you can tear them apart and see how they work.

http://www.civil4d.com/2006/11/another-intersection-sample-drawing/

PROBLEM #4: CHECKING PIPE COVER ONCE ROAD DESIGN HAS BEEN MODIFIED

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If you are dealing with a pipe crossing the road, you need to follow the procedures for tracing your pipe invert with a profile as mentioned here:

http://www.civil4d.com/2006/07/labeling-pipe-invert-elevations-in-a-profile-view/

and expanded upon here:

http://www.civil4d.com/2006/10/labeling-your-structure-to-structure-design/

(***Note that for some piping projects I’ve worked on recently, I have actually started using alignments and profiles to represent pipe runs horizontal and vertical designs until I get a good preliminary layout hammered out. This way, I can really leverage those expressions and references without the fuss of making true pipe networks until I am ready to commit, or at least closer to committing, to a design)

Once you have that profile, you can reference it in an alignment, surface or any other object that makes sense. Keep in mind, if your pipe vertical design changes, you must manually drag your pipe invert tracing profile, but it only takes a second and saves a ton of headache.

Here is a sample. This is a station/offset label with three pieces of profile reference text. Road Elevation, a Profile Expression for Cover, and Pipe Elevation.

For ideas on using Surface Reference text in Alignment Station/Offset labels, visit:

http://www.civil4d.com/2006/11/surface-reference-text-in-alignment-labels/

For more ideas on using expressions and reference text in pipe labels and to help with your pipe design, check out:

http://www.flickr.com/photos/civil3diva/sets/72157594303977019/

MORE PROBLEMS, MORE SOLUTIONS

I am slowly getting back into the groove after an extended Holiday snooze, so expect to see more posts on this subject and similar.Â

RELATED IDEAS:

A complicated stream from a corridor- also good ideas for complicated roads, berms and other record keeping nightmares:

http://www.civil4d.com/2006/12/corridors-for-streams-with-sample-drawing/

One comment

  1. mjwoodruff says:

    For me, this feature alone is enough reason to switch from LDT to Civil 3D. I can’t tell you how much time I’ve wasted going through and checking ALL my intersections, during design, and especially after a revision.

    Michael
    mjwoodruff@cadtimes.com