Building models for machine control help

Most contractors want a TIN based on finished grade. If they are really experienced they may ask for several different TINs: subgrade, rock grade, finished grade, etc.

Basically any software that can make a TIN is capable, but not all software is created equally. LandXML is the easiest way to transfer data, but some contractors may not know what to do with it. I have a few contractor clients that to figure out what they needed I got permission to go look at their software. Some are more proprietary than others, but should still allow for import of XML. Just remember that XML is usually the most flawless way to convert data, but even it can have a snafoo now and then (mostly when importing into older software).

I think building these TIN's will give you at least as much liability as doing construction layout at a fraction of the income. As a survey company I just wouldn't do it, just like I wouldn’t supply coordinates to a contractor to have his surveyor do the layout.

I've built many models for machine controls. Check out a quick overview at http://surveying--mapping.blogspot.com/
Good Luck!

Depends on the brand. I have extensive Trimble experience and some Topcon experience. Both have their own office softwares that convert surfaces, linework, and calibrations/localizations to a format their machines will accept. Some contractors will be able to import data and some won't. The surface can be created in any software, but there will be conversions. If you intend on pursuing I reccomend getting Topcon 3-D office, Terramodel 10.6 or higher with the data prep module or Trimble Business Center.

Look for machine control online magazine. There are many articles on machine control data preparation. You generally build a finished surface DTM/TIN to upload to the graders and dozers. The operators can then dial down the blade to cut whatever subgrade section they are working in.

Jason

Building the TIN for machine control is no different than building any other TIN for design except if you screw up a small segment, the dozer will build it that way.

I use Site Vision Office to convert the file to the format needed for the dozer.

For building the TIN, use whatever you are most familiar with.

James

Be careful furnishing finished grade, that can bite you if they don't know what they are doing. Some sites it's fine if everything is the same depth, but if depths vary, furnish subgrade. ESPECIALLY on road work. I had to correct a file somebody else had done where they furnished finished grade on a 4 mile stretch of 4 lane, then the contractor offset it, but the shoulder subgrade 2% slope did not follow the finished shoulder 4% slope. They spent about a month fixing the grade.
Terramodel is probably the best for road work, probably any of them for just site work DTMs. Take all the training classes you can go to.

As for liability, just make sure it says in your contract that the only thing you guarantee is that the file is correct according to the plans provided. Same as saying the stakes are correct according to the plans provided. Not the control, (unless you are setting that too) not errors on their part, etc. Make sure you and they both have a copy of the file you send so it can be checked if anything arises later. It's easier to prove who screwed up than them claiming a stake was marked wrong that is long gone. Then charge the same as calculating it up and staking it one time. Their benefit is they only have to pay for staking once, but they always have the grades. Get any questions answered before you let it out the door, with everybody signing off on any changes to the plans.

I done a few Models on large projects that I have been the stakeout guy on . It really was not worth it , the grader still argued with me about grades not matching mine all due to his rover not being localized correctly . They think they can ride around with out any stakes and then call me in to fine grade and guess what it dont match. I have seen a few graders make big mistakes with the GPS and the models. I find it funny they think they can survey thats what the salesman told them .

Let them figure out the darn model the whole thing has taken work from us .

Heck the Survey sales people are doing the models for pennys on the dollar. Ridiculous .

I don't think any of them think they can "survey". These guys are doing layout with equipment that surveyors also use to measure land boundaries....

Another resource:

http://www.gds3d.com/ArticleGDS.html

Steve
I can use a hammer does not make me a carpenter . I think construction layout is surveying . We are experts in the field of measuring and giving those results validity ,they are just pushing buttons. We need to protect whats ours no matter how good the equipment gets or how easy or we will be telling about our profession in the history books .

Their is a project in town that the Grading contractor spent 350 thousand dollars fixing a grading error due to his GPS error . This is not protecting the public.

We dont get paid for pounding the stakes we get paid for were they go .

Working on a 21 mil terrain model in C3D right now
and RD 2 depends on location of Rd 1

what a ^)#$&@*&$^@#*$ CAD C3D nightmare

its not about survey its ABOUT @*()$_@#(& C3D

Trying to relax breath deep.

Right on James

I have enough TerraModel experience doing designs that I don't think I'd have much problem doing the models. It's the future. You can either be the steamroller or the road.

I'm trying to get a contractor friend of mine to try it on a road project I'm doing for my self. It's already rough graded. I could tell if the model wasn't working correctly before the grader went a couple hundred feet. Same as anything else, use your common sense when your points hit the ground.

Reminds me once when I was supervising a pipe laying crew. Sewer line was on a 1% grade. I had to be on another project. Crew assured me they could get the pipe laser set right. I came back about noon and the pipe they were laying was about to come out of the ground half way to the next manhole. Turns out they have the laser set to 10% instead of 1%. All I could do was ask them if they were going to build a ramp into the next manhole. No common sense!!

Nice Blog!

> Steve
> I can use a hammer does not make me a carpenter . I think construction layout is surveying . We are experts in the field of measuring and giving those results validity ,they are just pushing buttons. We need to protect whats ours no matter how good the equipment gets or how easy or we will be telling about our profession in the history books .
>
> Their is a project in town that the Grading contractor spent 350 thousand dollars fixing a grading error due to his GPS error . This is not protecting the public.
>
> We dont get paid for pounding the stakes we get paid for were they go .

Well Said!

Thank You!