BIM on the Rocks

Using the AutoCAD DIVIDE Command with Civil 3D Alignments

I love using Civil 3D alignment labels to mark all kind of things- not just station values. It is such a timesaver to use an alignment instead of a polyline when you want that real-time measurement.

\We tend to think of alignments for roads, but think of anything you draw that you are constantly measuring- some ideas might be TC paths, fencelines, buffers, wetlands delineations and more. Add your comments below with other ideas.

Today I was working on an airport runway layout. Christopher was kind enough to send me some guidelines (UFC 3-260-01 Airfield and Heliport Planning and Design, with Changes 1-2; replaced by UFC 3-260-01 dated 11/17/08) last night. It looked like for my 6000’ runways I needed four taxiway turnoffs from the runway equally spaced.

First I reached for my alignment labels, but realized I didn’t know a way to get it to divide the alignment into equal pieces and then place the label. (There might be something creative you could do with expressions- let me know your ideas.)

I reached for an old favorite tool- AutoCAD DIVIDE.

1. Type DIVIDE in the command line, then choose the BLOCK option*.
2. Type the name of the block you want placed at the divide locations- AeccTickCircle is a good one that lives in the standard templates.
3. Enter the number of segments- I used 4.

 

Sometimes, its the simple old favorites that give you what you need. Now I have markers where I need to make taxiway alignments.

* note that the other option does not work with Civil 3D alignments.

Civil 3D and a New Zealand Airport

I’ve introduced you to my friend Peter Thomson a few times. He’s the dashing voice behind this youtube video on a workflow for creating a rising main (or forcemain) using Civil 3D.  and I attended his class last year at TeamBlue22’s Civil 3D University in Auckland.

Last week, Peter sent me some pictures of an airport Runway End Safety Area (RESA), his team worked on with Civil 3D 2008.

My first thought when I looked at the photograph was… Man. New Zealand is so ugly. Once I was able to look past the breathtaking mountains and interesting topography, I narrowed my focus to the terraced RESA area at the end of the runway.

From Peter:

A short distance from Queenstown lies Frankton where the Queenstown International Airport is located. Civil Aviation rules have stated that the runway needs to have a 90m x 90m Runway End Safety Area (RESA), a grassed, flat area at both ends of the runway.  MWH NZ Ltd was one of a group of consultants engaged to effect the construction of the RESA at the eastern end of the runway.

A feature at this end is a 45m high terrace sloping down from the runway to the Shotover River Delta. The construction of the RESA is combined with providing for the accommodation of a future local road around the end of the RESA. The result is a benched fill of around 800,000m3 containing various fill elements which have all been modeled in C3D. MWH at that time was using a C3D add-on software package called Advanced Road Design (called Corridor-EZY in the US) and this was used to build the surface model of the RESA.

Sub-surface layers were modeled using feature lines by extracting contours from working design surfaces. This also enabled sub-surface volumes to be calculated quite easily.

All in all, C3D has proven to be a valued tool in the documentation of this high-profile project where the construction of the RESA must proceed without disturbing the operation of the airport.

On an interesting side note, Justin Ralston (Airey Consultants) is a design engineer working on an adjacent development project where fill for the RESA is being extracted. I actually “met” Justin on the C3D Discussion Forum some years ago and we have struck up a useful association with C3D where we both enjoy teasing Dana on an on-going basis to give us what we are looking for in C3D future releases. We finally all met in person at the New Zealand version of C3D University last September in Auckland.

Peter also told me that all of the surfaces were exported to LandXML for use in machine control. Excellent!

I am pretty sure I talked Peter into submitting an AU class proposal this year- I can’t wait to see what he has to offer. Hopefully I can talk him into coming to Las Vegas and meeting more of those contacts from the Discussion Groups. (Also, giving him an opportunity to tease me more.)

Learn more about worldwide projects at MWH on their project search page.