Being Civil

Advanced Daylighting Design and a farewell...

Hi all - this design scenario came up a few weeks ago, funny enough from two different sources, in Europe and North America.  How do you design an Assembly that in cut conditions daylights from the hinge point and has two parts (see below); first a variable dimension (x) and then a second part with a fixed dimension (y)?  As you may know, at first glance Assemblies can only have a variable dimension on the "last" daylight portion, where you just tell the Subassembly to find the surface wherever it is.  This seems impossible - how could we achieve this?

  

Order! Order!

I know its been a couple weeks since I last posted.  With the Holiday, vacation, and then adopting a Doberman, things have been a “tad” busy.  But it’s great to be back into the normal daily routine. 

Today is a quick one.  A customer asked a great question last week.  “What order is the Assembly built when the Corridor is created?” 

On the Construction Tab of the Assembly Properties, you will see a list of all of the Subassembly parts.  During the Corridor build, Subassembly parts are built from the top down.  Why is this important?  Well, it may not be for most Assemblies, but here is an example of where the order is important.  When using a Marked Point and Link to Marked Point, you must make sure that the Marked Point is higher on the list.  As long as you create the Assembly this way, the list will be correct.

Odd Corridor Behavior with TrenchPipe3 Subassembly

The TrenchPipe3 Subassembly can be used for building a trench for your Pipe Network, giving the option to target both a Rock Surface, as well as an Existing Surface.  This is great for allowing steeper side slopes when blasting your trench into bedrock, but then keeping milder slopes above that, in natural ground. This is a new Subassembly, and I don’t think it is being used all that much.  But I noticed some odd results from a user recently.  It is an easy fix, but one that can easily be overlooked.  Here is what the Corridor looked like, in it’s incorrect form.

Notice how the Corridor is split up into many sections and not daylighting correctly.

The Grip With the Long Name on Assembly Baselines

Occasionally, a user will discover something that I have never seen (or noticed) before. That tends to not bother me too much, as I realize that Civil 3D is a very large program that does many, many tasks. But yesterday, a call came in about a grip that I’ve never paid attention to. The question did not pertain as much to “what is that grip?” as it did to “what does that grip do?” So to answer the question, I embarked on a journey and finally figured it out.

But This Subassembly Requires Superelevation!

Earlier this week, I was pinged by a colleague who was curious about a parameter in the MediaDepressedShoulderVert – it seems as if the paved shoulder links were defaulting to a slope of 5% and could not be changed in the properties of this subassembly. His customer wanted to change this slope, but simply could not find a way to do so. I scratched my head along with him and looked into it just a bit further, waded through the documentation that seemed pretty ambiguous (to me, at least) and then decided that I knew where I could find the answer. I went directly to the source – my good friend Nick Zeeben, QA Analyst for Autodesk.

Nick argued that the documentation was perfectly clear -  it states the following:

The paved portions of the shoulders follow the slopes defined for the left and right inside shoulder slopes for the baseline alignment’s superelevation specifications. These slopes are applied inward from the inside edges of traveled ways. The unpaved portions of the shoulders are fixed at the given Unpaved Shoulder %Slope value.

OK, so you have to have superelevation for this to work, right? That’s what it says in the help file! My question to Nick was how to change it if the baseline alignment did not use superelevation. His answer was simple – create a superelevation entry without calculating superelevation. Huh? He explained that there simply needed to be an entry in the superelevation table that contained the desired values and everything would calculate correctly. Let’s say that we want our inside shoulder to be at 4% rather then the default of 5%. If we create our corridor as we normally would and have an alignment with no superelevation defined, then you will see in the following illustration that our inside shoulder slope is definitely set to 5%, which is not what we want.

To fix this problem, we have to specify superelevation data. To do this, simply select your alignment, right-click and select Alignment Properties. Next, select the Superelevation tab, which should be blank. To add a superelevation region, select the Add a Transition Station button as illustrated below:

You will be asked in the command line to specify a station along the alignment, so enter a station of 0 (this is the beginning station of my alignment, adjust your values accordingly.) Once the transition region is created, you can simply change the Inside Shoulder values for both the left and the right side to 4%, as shown below:

Once you enter this information, simply click OK and then rebuild your corridor. A quick check of our corridor through the View/Edit Corridor command shows the updated value of 4%.

Once the light bulb came on over my head and I understood it, it made perfect sense. Here’s hoping that it helps clear up for you as well!

Have a great weekend!

Note: Just before I posted this, I checked this site to see what type of formatting and post style that Brian and Justin were using – I wanted everything to look roughly the same. When I glanced at Brian’s last post, I thought “no WAY he could be writing about the same thing!” But it seems like we ended up choosing polar opposite topics to talk about – his on subassemblies that don’t use superelevation when he wants them to and mine about subassemblies that use superelevation when I don’t want them to. OK, I thought it was an odd coincidence ;)

Matching parameters across Subassemblies

There are times when you want to use a collection of Subassemblies but maybe one of them doesn’t have a Superelevation parameter, which is what you need.  Or perhaps you are creating some standard Assembly templates that string together a number of Assemblies and it’s a real pain to use, when you have to change widths, thickness, etc. for each one.  What to do?  Have you looked at the Assembly Properties > Construction tab?

Here we have an assembly with LaneOutsideSuper and then a BasicLane.  But Basic Lane doesn’t have Superelevation as a parameter, so what am I going to do if I need it to follow Superelevation criteria?

Select the Assembly, right-click and go to Assembly Properties, then click the Construction tab.  Select the BasicLane subassembly, and notice how I can set it to follow the slope settings of the LandOutsideSuper assembly.

This could also be useful if you have a multi-lane highway Assembly with similar widths; set them all to match the width of the “first” one, and then you only make one edit and they all follow along.  Or maybe you have a template with depths that are the same for all subassemblies – same thing. 

You do have to consider each side, left and right; you cannot follow a parameter from the other side of an assembly.  Just one more tool for your belt, to remember when you might need it!