Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Earthwork Computer Program 4

Status
Not open for further replies.

waterguy926

Civil/Environmental
Nov 15, 2002
5
0
0
US
I am trying to find the most accurate computer program that calculates earthwork based on AutoCad files. Can you please give me some good suggestions?
 
Replies continue below

Recommended for you

We use EaglePoint software at our office. Been using this for close to 14 years.

They have integrated the design software with ACAD fairly well. The Surface Modeling module works quite well and simply to develop DTM's and calculate quantities.

Of course ACAD has it's own suite of design tools and I've heard good things about them as well. If you haven't yet made a large software investment, check out SiteComp. This is totally independent of ACAD, has all the cogo, engineering design features and surface modeling capabilities as other packages but doesn't require ACAD. I checked this out and was impressed with it. If we weren't so invested in EaglePoint, with so many stations, I would have really pushed to switch.

David
 
The type of software you need will depend on whether you are a contractor or architect/engineer. If you are a contractor, the company I work for, InSite Software Inc., makes a very comprehensive earthwork take-off package, that can import dwg and dxf files. You can see it here:


Click the home page to see all the other features InSite SiteWork provides. While products that run in the CAD environment can do volume calculations, it is very difficult to handle multiple surfaces. When you consider that often sites require topsoil stripping and demolition from the existing surface, cuts broken down by strata type, fill requirements for the whole site as well as for each structural and non structural area, subgrade volumes, and topsoil replacement quantities, it becomes quite difficult to calculate these in CAD based software. There was a pretty good discussion of contractor-based packages here:

thread158-17845 you have any questions call me at 1-877-746-7483.

Thank You
Steve

Steve Warfle
InSite Software Inc.
 
In my experience nothing beats the human brain! I have used several estimating programs and the "trick" is to know how to perform the analysis by manual methods so you can check the programs. Different programs use different assumptions for their standard model and you need to find out how the program calculates it's volumes so you can see if it is the best match for your situation.

For a 2,000,000 cy project at Vandenberg AFB I used a combination of Tundra Data Earthwork for the building pad information and cadd drawn cross sections of the rail bed with a custom spreadsheet to interpolate between stations and calculate the mass haul diagrams.

The end result of this was a balance of +/- 200 cy over the 2,000,000 cy project but it took a lot of work! In my situation it was worth it.
 
I agree with RAMenterprises - in any computer programme in use, we need to have a good judgmental idea of answer in order to believe the output.

Alhtough having not used it, I have heard good things about mxroad.

Best regards.
 
RAMenterprises and BigH are right about being too trusting of computer programs. I use AutoCAD R14 with Softdesk and have found their earthwork programs to give good results IF PROPERLY USED. You alway have to check the "surfaces" that the program generates to see if they make sense. It is easy to make errors in the use of the program which are not obvious and can radically alter the results. Often I check the final earthwork the "old fashioned" way, either by hand and outlining finished grade and existing contours with colored pencils and planimetering the area, or by using the computer to do the same thing. By converting all my contours to polylines, connecting and trimming the finish grade and existing grades, drawing a daylight line, then cutting and reconnecting the polylines into areas for each contour. I then use the program to calculate each area, after which I add up the areas and then adjust and finish the earthwork calculation manually.
 
Ment to add to the above post, by using polylines and creating areas as I mentioned, you could do the earthwork calcs just using AutoCAD, without an add on program. It would be less convienent, but it would work.
 
I have used SoftDesk and AutoCadd Land Desktop for about 10 years now, and have found the earthwork tools to be very good. As previously mentioned in other post, it is imerative that you know how to check the work, so that you have a high confidence level in the numbers that are generated. The old saying " Garbage In - Garbarge Out" definately applies here.
 
I've used both softdesk and InRoads. I think InRoads is a little easier to use. After you run your templates to create your proposed surface you can easily calculate the volumes of earthwork. You have to be careful and understand what information you are given by the program before publishing your results, though. I usually backcheck that information by comparing it to the cross sections using the average end area method.
 
We use the MX suite for all our civil design works. Roads, site, rail, drainage etc. this suite works in windows standalone and inside ACAD and Microstation so we are producing final drawings direct from the software. I have been using it for over 6 years and find it fantastic for the one off projects that you get "right first time" to the large projects that you are redesigning just infront of the earthwork machines. Having all the design works incorporated into one package is fantastic as you have the live model when you working on the drainage or the building platforms.
As this package works inside ACAD. if your design is ACAD 3D, you can readily merge the ACAD and MX models to get you volumes etc


Regards

Steve Muller
MWH NZ
 
Snafuman:
your method sounds like a good check and a good way to get a "feel" for the e.w. quantities. My problem is following exactly how you do this -can you direct me somewhere? and what exactly is the daylight line?
I have only done e.w. using profiles drawn through a site and then computing the average end area of cuts and fills, so though this sounds more accurate, it is also unfamiliar to me.


Andy
 
ABW
Think of a wedding cake as a very simple grading plan. The table is the existing grade. Each layer of cake represents one foot of fill. The area of each layer, times one foot, gives the volume of that layer. Add up the volume of each layer to get the total volume of fill.

Now look at your grading plan. The existing contours are the "table", of course they are never flat. Pick one contour elevation and trace the existing contour with a red pencil and the finish grade contour with a red pen or marker. The area enclosed is just like a layer of the wedding cake. Measure this area with a planimeter. Of course there may be more than one area enclosed, because there can be both cut and fill. The points where the red pencil and red pens lines cross are your daylight lines, where you are either matching to existing ground, or transitioning from cut to fill. Now do this for every different contour elevation on your plan, using different colors (I usually start repeating colors every 5 contours, there just aren't enough colors to do a complex grading plan with all different colors). Draw daylight lines through all of your daylight points to separate cut areas from fill areas. Measure each separate area of cut and fill enclosed by the same color, (use highlighter to separately color the cut and fill areas) multiply the areas by one foot or your contour interval, to get the volume of each area of cut or fill. Total up your cuts and fills. Don't forget to apply shinkage corrections. Also, if your grading plan contours are drawn to finish grade, don't forget to correct your cut and fill quantities for the volumes of subbase, base, pavements, concrete, etc.

While this is a difficult procedure to describe in words, if you were here I could illustrate it to you easily. I believe it would be less tedious than the method you are using, although any earthwork method can be tedious, even the computer generated ones.

As I described in the previous posts, I have done this procedure on AutoCad, although it is just about as much work to do it on the computer as to do it manually. I have found that it gives very similar results to the grid, composite and average end area methods which the Softdesk programs generate, when everything is done right.
 
My only experience is with a program called Qwest estimating solutions, is was the norm for the contracting company I was hired in to. I would not recomend this program at all, it seems to be designed for the guys driving the dozers. Very few options and all in all a very poorly designed program.

AJS

 
Snafuman:
Thanks for your explanation! Difficult as it was to explain, you did an excellent job, and I think I actually understand it. I will try it on my next job.

Thanks again
Andy
 
Software Used:
Land Development R2
My own custom Excel Spreadsheet

Methods:
As others have said, you should certainly know what to expect rather than rely solely on what an application tells you. To simplify the process for many users, I've developed a basic process and that is as follows:

1. Start with two surfaces:
A. Existing with topsoil present or enter 0's in the spreadsheet where appropriate when you get to that step.
B. Your finished grade to top of pavements, etc. I highly recommend the extensive use of fault lines for quality topo and accurate quantities
2. Establish thicknesses of topsoil, pavements, etc.
3. Establish swell factor for your soils
4. Do a volume calculation between your surfaces using no adjustments
5. Do a cut-fill tick map and set the Grid surface current in Terrain Model Explorer. Topo it so that only the 0 contour will be created.
6. Determine areas of pavements and topsoil in cut and fill, and enter those values in the appropriate spaces in the spreadsheet
7. Enter the raw cut/fill numbers in the appropriate place in the spreadsheet
8. You should now see the numbers you are after. Numbers returned are:
A. Common Excavation
B. Off-site borrow
C. Off-site disposal
D. How much to raise or lower the site to balance
E. Undercut (if specified)
F. Volumes of pavements

The only thing left is that you need the spreadsheet. Drop me a note at inquiry@cegroupinc.com if you want to give this a try. Instructions for use of the spreadsheet are contained on a separate tab and in comments attached to individual cells.

Please note that this is just an aid in design provided at no charge. We cannot accept responsibility for errors and omissions. Please report spreadsheet corrections, modifications, additions to the same address. A blue bounded box in the spreadsheet is a good location for a company logo if desired.

I hope that you find this to be helpful.

Jeff Foster, PE
CE Group, Inc
 
Unfortunately because of the base data of any earthworks project being based on survey work, there will always be inaccuracies.

This is not because the surveyors can't do their jobs, but because the points collected are always approximately representative of the ground surface. To clarify this I recently carried out a large earthworks design project which was based on a 50m grid over an 8km by 8km site of undulating hills of which some area were subject to ongoing erosion.

Because of the inherent inaccuracies of the survey (+-15mm), the grid spacing and the size of the site, the resultant volumes may be up to +-15% in error. So despite using quality software we were still relatively inaccurate with the client being advised so.

So to the original question, what is the most accurate program to use for earthworks? It doesn't really matter because of the factors that are outside of the control of the designer and inherent in any earthworks project. You are better to find software that is easy to learn and can produce quality results through offering a variety of checking methods. For example LDD has 3 methods of calculating earthworks, which gives a good indicator of the errors involved in each design.

In my experience if the program only uses one method to calculate earthworks, then it is seriously flawed, as it is better to check the volume by different methods where-ever possible.


Regards

SC
 
I too am a Terramodel/Paydirt user and compleatly agree with the non-user friendly comments. Try training people with it. I am totaly fed up with donut holes and all the other short comming of the product. I have also used Agtek/Autocad combination with about the same "user friendly" attitude. I don't know if it exists but there is a demand for a less obtrusive interface for LDD for use by contractors and such. Does LDD have a easy way to allow for compaction, area cuts and fills segrated from other areas, adjustments for subgrade, stripping of existing surfaces, strata, material designations for subgrade adjustments, all with comprehensive reporting of the same?
Even though we have several seats of Paydirt, I'd dump it in a minute if there is something better out there. I have looked and/or used Agtek, Paydirt, InSite and Quest. They all have short commings that don't make one a better choice than the other. If you are able to resolve your delemia, I would like to find out what you came up with.
 
Status
Not open for further replies.
Back
Top