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Key Based Site Design in Civil 3D

Tags grading, site design, corridors, standard keys, CAD Standards, Layer Standards, corridor surface, surface


Folk complain that AutoCAD Civil 3D is not really user friendly about Site Design. The complaint is true if you insist that site design in Civil 3D should be like it was for years in Land Desktop. Unfortunately, about the only thing Civil 3D has in common with Land Desktop is it’s use of similar but historically deceptive Ribbon names such as Surface, Grading, Parcel, and Alignment.

You know by now that a Civil 3D Alignment has almost nothing in common with the old school CAD object. When I explain to students that Parcel segments are effective Surface breakline grading tools people often become bewildered. Say what?

The Dynamic Model Takes Her Gloves Off

Autodesk made some major site design improvements in Civil 3D 2017. Say what? The ability to employ a Feature Line as a Corridor Baseline has been on my Civil 3D wish list since 2010. I know. I’m sorry. From my somewhat perverse perspective a Grading should always have been Assembly based. Case in point about wishes and horses - the corner resolution problem could have been fixed way back when. Autodesk was clearly not going to fix Grading Features. Frankly, 19th century drafting methodologies can’t solve the topological problems. Linear interpolation cannot solve planar and conic interpolation problems. The math is out there.

The new capability to employ Data Referenced (DREF) Corridors will also create some new workflow opportunities that shorten production decision making, quality control, and publication for Complex Corridors which are the meat and potatoes of site design –all design- in Civil 3D.

We better have our data management and project concepts, structures and skills up to snuff. We certainly need better Style tools. We surveyed some of the significant Style issues last time.

Complex Corridor Basis…er…Basics?

The workflow concept of Complex Corridors is simple. We employ a corridor to build a design solution. That design corridor becomes another Baseline to our managed (Complex) Corridor that collects these parts ad nausea. The Civil 3D Intersection is a classic semiautomatic example, but the intermittent workflow wizardary of the Intersection is only part of the story. I trust you never go through the Intersection Wizard in one pass? Say What?

People do get stuck on the classic roadway corridor idea that one Assembly has to deal with the entire cross section.
How well we manage and employ the Civil 3D Design Control Managers – Alignments – is mission critical. Why there is a Book of Alignments.
We now have more liberty.

Feature Lines as Baselines in 2017 means they become a Civil 3D Design Control Manager too. This will probably be more comfortable for site design folk many who favor point to point design methods. Maybe it will helps site design people grasp the point of and benefit of managed corridor design. This will require some support.

Users still have fundamental design visualization issues to cope with.
The reality of Civil 3D is that old layer tools by themselves can’t really cope well with Corridor visualization which is Style based by design and by necessity.

The Daily Civil 3D User Issue

“I do basic site and subdivision design. Where are the layers and style tools for that?”

The Key is how do we think and talk about that? Maybe you consider the right of way line the separator between the ROAD and the SITE Keys. Historically, Autodesk’s way of publically talking about Civil 3D tools and Corridor Features favors this. Their sad example templates encourage this distorted CAD think. Case in point Autodesk Profile View styles to go to ROAD layers. If you do lots of shopping center or business park design, DRWY and PRKG perhaps supersede both other Keys.
For those who do site design the Civil 3D words are wrong therefore, the tools don’t help. Buzz. Thanks for playing. This is discipline-based layer management thinking. This is CAD think. Even if we are skilled at Civil 3D we can suffer for it.

Site Design Identity Crisis

We face a form of identity crisis- a visual quandary of meaning, “What the hell is that?”
To put it bluntly - How do we differentiate and identify my ditch from my channel from my bank and from my levee when everything is a corridor?

We’re dealing with representative Models. Models are about Systems, Structures, and Parts (and all of these collections) by definition. These do in part relate to classic CAD layer systems. See the link to Layer Standards in Civil 3D.

The Framework for Civil 3D supports an open list of Civilized Keys for the National CAD Standards. The list for customers includes the complete AIA’s NCS list. The Open list includes civil engineering and survey Keys and the list is fully documented.

In Civil 3D we employ Style to manage what we see at the moment. The last thing we should worry about is what layer it ends up on, but we all must agree some form of integrated system of meaning is important to our daily work. This is a real world and serious Style problem.

The Release 6 of the Framework provided to every Civil 3D using organization (and AutoCAD ones too) the ability to manage the intimate property details of that visual meaning and identification via the accepted industry standard methodology or a standard Language of Keys.

I acknowledge that this new liberty of property independence and the capacity for adaptive standards for Civil 3D takes a while to get your head around.

The Style Tools Don’t Care. You Do.

Your POND in my BASN. Your BANK is my EMBK. Your DTCH is my DIVR. From a design control and data management and design perspective these different sitework structures are actually remarkably similar. As Systems they have similar Structures and varied but also similar Parts from a Style point of view.

All the way back in Release 4 we initially introduced Alignment, Profile, and Parcel Styles (some purely annotative) that reflect these site design user needs. In Release 6 you’ll find them in the Jump Kit Library resource drawings with the SITE suffix names. For a number of Civil 3D releases customers have successfully employed these Style Tools to produce well-managed sitework corridors. People requested some better and more detailed Feature Line support. We do this for Survey Figure generation - No problem.

Predictable Site Design Tools

In Layer speak if our site structure is a Major Key like BERM, then there are another predictable collection of standard coupled Minor Keys.

TOPS, BOTS, OFLT, OFRT, FOOT, WALL, and CNTRs (maybe this last could be CTRL but you get the idea). (The offset Keys are intentionally generic to help users deal with the vagaries site design problems.)

Therefore BERM-TOPS, BERM-BOTS, etc Feature Line style names make perfect sense. Replace the Major Key BERM with your preferred site structure and you get the idea.

More Innovation Beyond the Code

In Release 7 we’ll introduce and supply new By Key Style collections which will include matched Alignment, Profile, Parcel, and Feature Line Styles of the all the Major Keys of sitework. These should make the construction of complex Sitework Corridors a lot easier to manage in daily production work. You can consistently identify what you are getting and better manage the results by style.

We Play Connect the Dots by Keys

Your site structure of choice should be a matter of design language preference. How you get there is up to you whether you drag and drop by Style, Style Import, or by drawing (insert|exploded), or now use a Reference Template (in Civil 3D 2017).

You should be able to design and build your model generically and publish it specifically on demand.
Now maybe that makes sense?

Production Solution customers know by now we’d never forget the publication and annotative problems so you get a wide variety of annotative Styles and Label Styles too. More on that is the near future.

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