Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Earthwork û Plotting Sections from Contour

Status
Not open for further replies.

MedNeuvo

Geotechnical
Sep 8, 2006
15
I wanted to know how to draw earthwork cross-section in AutoDesk Land Desktop from the contour plotted in AutoCAD file (*.dwg file).

Can anyone please help.

Thanks.
 
Replies continue below

Recommended for you

Are the contours hand drawn (polylines), or were they created from a surface (dtm) that was created with the electronic grading modules?

The cross-section menu of LDD will allow you to cut cross sections along an alignment as long as you have surfaces to sampe terrain data from.

If you can provide some more detail, I can suggest some methods for getting the desired cross sections.
 
The contours are created in AutoCAD drawing file, and there was no z values stored in the file.
 
If you want to use LDD to draw ( or "cut") the cross sections, you will have to assign the Z values to the contours and make a DTM file, or get the DTM file,if the DTM file exists.
 
Could you please tell me how to make a DTM file in easy steps.

Thank you.
 
Step 1, add elevations to each polyline (select 'properties' for each line and give it a Z elevation).

Step 2, Under the 'Terrain' menu, open Terrain Model Explorer. Under "Manager:, choose 'Create Surface' and give it a name.

Step 3, set the new surface current by right-clicking on it and selecting Open (Set Current). Click the + (plus) sign by the surface name to expands it's list.

Step 4, from the newly expanded list for the new surface, choose "breaklines", and select "define by polyline". The menu bar will prompt you for a description for the breaklines (i.e. proposed contours), and then prompt you to select all of the desired polylines. Right-click when done.

Step 5, right-click on the surface name and choose "build". From the "build" screen, enter a description in the designated area, and from the selection list, choose only "breaklines", as that is all of the data you have to make the surface from.

Step 6, hit 'OK" on the build dialog box and watch the computer process the data.

Step 7, once the computer is done, you can save the surface. To preview the triangles created by this process, from the Terrain menu, select "edit surface" and "import 3d lines".

Step 8, once you are happy with what you created, process the cross sections using both the existing and proposed surfaces (create an existing surface from the existing contours if you don't already have it) and create the cross sections.
 
saruman26
I lost you in step 8.

create a surface from the existing contours?

I thought this was done in step 2.
I appreciate some clarification.
 
There are a couple things that lead up the the sections.

You will need to make an alignment that will run perpendicular to the sections that you want to make.

An easy way is to draw a polyline, then go to the Alignments pulldown and define it from the polyline.


 
You need to create two surfaces for everything to work: an existing surface, and a proposed surface.

BelspringKen is absolutely correct - there are several more steps and tools necessary to accomplish the task than just creating a surface.

As cumbersome as they may be, the manuals that came with the LandDesktop software may be useful in this case. Learning which tools are required and how to orchestrate the numerous menu options into a finished product is really key, here. In my office, this subject could easily take a couple of hours for me to teach to another engineer.
 
saruman26:

I am still having trouble to draw the section. The countour lines are grouped together and I can not ungroup them in Land Desktop.

If I have your email, I can send you the AutoCAD drawing fine.

Please help.

Thanks.
 
sounds like a block or reference file. Maybe some more basic autocad training would be in order. Try the Autodesk: AutoCAD Forum.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor