An InRoads user asked for Mark's thoughts on this question :

Hi Mark,

I have a question from a contractor for me to give them information for grading a project.  Would you have any idea what files / type of files I would give them? I have never been asked this before.  They are not sure either, the information has been provided to them by others in the past.  

I would think it would have something to do with the design DTM, not sure.

Any suggestions would be helpful. Thank you for your time. 

Mike  

Here is the Zen Dude's response:

Hi Mike!

It depends on what they want it for. If they want it for staking and expect to upload it to one of their survey Controllers then you can help them by knowing what Controller they have. For instance, InRoads can export the DTM and ALG for Trimble TSC 2's and TSC 3's. And there are Application Add-ins for exports to Leica, Carlson, Topcon and others. Some of these are part of the InRoads Application Add-ins.

Once the Application Add-ins are toggled on, these and other methods are under InRoads > File > Translators.

If they want the DTM for AMG (Automated Machine Guidance) or Machine Control work then they will have a special format that they will need the data in that you won't be able to provide directly. They will have to use something like Terramodel or Site Vision Office to take the DTM data and export the files they need (for example: SVD, SVL and CFG) that are taken to the grader. The specific system they are using will drive the file type that you give them because Terramodel can open a TTM that InRoads can export and then also stair step that data beyond that to create the necessary Machine Control files.

Probably the safest way, without knowing anything (and most universal) is to just give them an XML export of the DTM.

To cover all the bases I would give them this:

1)    A MicroStation 3D DGN (or two) of the grading features and triangulation (just display all of the DTM grading Features and the Triangle display on a different level) Some programs can read this 3D graphical data into their software systems and reconstruct the surface, or can extract out what they need.

2)    An InRoads DTM of the finished grading (just in case they have access to InRoads)

3)  Do the same things as above if you have a subgrade or rough surface; however if the rough grade or subgrade is parallel to the finished grade it's not that important and they can make the necessary adjustment for parallel depth control on the grader. In Canada where the subgrade is not parallel to the finish grade they would need both.

4)  Use the InRoads > File > Translators > LandXML Translator and export out a couple XML files:

a.     One with just the Features

b.     One with just the Triangles

c.     One with both the Features and Triangles

But what you really need to do is open up a deeper discussion with them to see exactly what they can use, and see if you can provide that.

This is a slide from my Field to Finish presentation that shows the movement of electronic files along the span of the job. These files relate specifically to Bentley / Trimble products.

All of this is pretty new to most people on both the Engineering / Survey side as well as the Contractor's side, so the best recommendation that I can give is to just discuss it a lot and each side will have to learn more about what their piece of software can both import and export in this data exchange.

Just as a side note - Both Bentley and Trimble, as part of their strategic alliance, will be introducing new software at the end of this month that is intended to make the exchange of information between the engineering design drawings and the field much more seamless. This is the first cut of this new functionality, but it shows that this exchange of engineered information is deemed very valuable in the eyes of the software vendors.

I hope this helps!

Civilly yours,  

-zen