Using Slopes in Earthwork Calculations? 1

[clarku19]

I am working with pre and post-dredge data, and need to run calculations between the two surfaces. This project is using a 3:1 slope at the dredge boundaries, and I was wondering if Terramodel can work with specs like this? In the Earthwork Settings, I do not see anything regarding slopes, etc. Maybe this is elsewhere?

For calculations I also use Surfer, but it does not allow the use of slopes and only refers to 'box cut' between surfaces. If Terramodel is not capable of using slopes, are there any recommended programs (besides Civil 3D) out there?

Thanks for your time. Much appreciated.

DP

 

[francesca]

Terramodel can compare surfaces, but you may need to manually grade the tie-in slopes. (It can do roadway/lot grading tie-ins, but I never used it that way.) We used to compare our existing and proposed grade (minus assumed topsoil depth). I can't for the life of me remember how, but I'm guessing if I could it wouldn't be much use to you because it was in 2004/5.

Yes, Civil 3D will do your grading for you fairly simply, but apparently so will Geopak Site Modeler (which is also now in InRoads V8i). I'm fairly sure Carson Civil could do it.

If you already have Terramodel, give Trimble a call or email their tech support.

http://www.trimble.com/tkn/

 

[BigH]

Sorry - it sounds like the cross sections aren't too complicated. if this is the case, why not do it manually? Just a thought.

 

[clarku19]

Thanks for the reply.

I'm am not sure how to go about manually creating the slopes, but I can look into that. Also, I have not paid for the preferred support from Trimble. Which is why I'm here.

From what I can tell, it seems that most programs that allow surface comparisons only allow a box cut (Surfer, Terramodel, Global Mapper). Civil 3D allows slopes, but it also costs a pretty penny (I'm a one man business). I have Map 3D, but I think that Autodesk no longer allows a break in the cost when upgrading. I left them a message yesterday. If I 'have' to get Civil 3D, then so be it. I would just like to see what else is out there, since Map 3D provides pretty much everything that I normally need.

I will take a look at the programs you mentioned. And thanks again for the reply.

Have a good one,
DP

 

[BigH]

Basically you hand draw cross sections of your cut and then use end-area methods determine the volume - what you computer programmes do but you do by hand. When I started this was the only way to do it and we had a planimeter to determine areas.

 

[GRunyon11]

TerraModel can handle any kind of slope that you need. There are two different ways of creating the slopes ... you can set up a roadway with a horizontal and vertical alignment, create a template, and slice the template to meet existing at a 3:1 slope. Or, you can use the sideslope command under the DTM menu, and set up 3:1 slopes either up or down. I typically use the sideslope command when I have a breakline that I want to project either up or down to meet existing.

If you set up the roadway, you can actually calculate average end volumes, or you can create a dtm for the finish surface, and then run dtm volumes between the surfaces. If you use the sideslope command, you will have to run the dtm volume report.

Hope this information helps.

 

[beej67]

^^Grunyon11 spells it out as best as I remember it, although the last time I saw Terramodel was about ten years ago.

It's also fairly easy to do this sort of thing by hand as BigH spells out. It'd take a talented cad tech with ACAD Map 3D half a day to a full day to do, presuming the level of accuracy you need is reasonable.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[francesca]

End-area method is not a patch as accurate as surface volume comparison and entirely useless in non-linear areas.

To manually add in the side slope you draw in your proposed contours by offsetting them the required horizontal distance for the contour interval (so 6 ft for 2-ft interval) and then add the contours to your proposed grade surface. It's not as elegant as GRunyon11's method, but is quick & dirty.

 

[clarku19]

Thanks for everyone for the replies. Very much appreciated.

I have decided to just upgrade to Civil 3D, since I know it is capable of doing what I need for these various dredging projects (and Autodesk did allow a bit of a break in cost). Now, how to do the slopes in 3D? Thanks another question...but I'll figure it out once the program is in hand. I may end up back in these forums though.

Thanks again.

DP

 

[francesca]

Download the User's Guide and go to Gradings. It's pretty easy.

http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=8777904#section8

 

[scout123]

You can set left/right cut/fill slope setting for the whole project and change it at any point in the project (or use a variable slope) between existing and proposed using EARTH software (

http://www.earthworksoftware.com)

-- you don't have to do hand calculations, but you also don't have to get into CAD.

 

[ishvaaag]

For people that only has to measure earthworks sparsely, they can proceed speedly and very accurately if they are able to model the terrains and earthworks in 3D. Autocad, Inventor, Spaceclaim and surely some others can give quite precise measure of the volumes of the pertinent solids at hand of whatever the shape. They have also tools to create solids through profiles, booleans and to autocad you may add a number of topography tools to what directly available.