Jump to content

Cut and Fill volumes


Recommended Posts

I have created a site model for a patio detail. The site model has elevation station ponts. I would like to excavated a volume of material which is unsuitable for the base. I will bring in an aggragate road base for a suitable base material. I have used the grader tool and set the elevations but am unable to produce a cut volume. How can I calculate a cut volume?


Link to comment

Cut&Fill compares the Existing & New DTM Models and then does the subtraction and/or addition section by section to produce the calculations of volume.

Basically, you need to have the Existing DTM one one Layer and point to the New DTM on a separate Layer prior to running the routine.

Link to comment

Thank yuou vey much for your help. If I am to understand you correctly I need two DTM's. Each on a seperate Layer? I am not sure how I point to the New DTM to run the program? How are the DTM's linked? I understand the rationale, but am not sure regardings the process? Can you clarify. Thanks again.

Link to comment

Islandmon, are you sure they have to be on seperate layers?

I thought proposed and existing DTMs were contained within the Site Model Tool

In the Object Info Palette make sure when you use Site Modifiers they are acting on the proposed DTM

So create your site model then modify it with pads. the grader tool - read up in Help about Pads, Fences etc -

You then should have two site models - existing and proposed and the volumes should calculate

The DTM is an amazing tool but it needs a good rebuild - I am hoping for that

Link to comment

Thank you very much for your suggestions and assistance. Is the initial DTM produced using the existing elevations/data and the DTM using the Modifier proposed? I would like to excavate and back fill with an approiriate material. I thought that I would be constuctring a textured bed for the paver patio application. Is this correct?


Link to comment

Existing DTM from you initial input

Proposed from Site Modifiers - make sure you have that right in the Object Info Pallet - I think it says Apply To and you choose Exiting or Proposed

Sorry I do not have VW open

You can use a Texture Bed and I think but am not sure also you can use the Hardscape Tool - never tried it

If you need to you can select the Site Model - right click/Edit and change your original source data

Also after most things you do you have to Update the Site Model - so keep updating it

Good Luck

Link to comment

Some versions back the DTM underwent a metamorphosis and became the "Site Model Object". This object contains both the existing and the proposed DTM (or Site Model as it is now known). It also contains the source data. So, if you are using a recent version (and you are alfresco - 2008), you can't keep the existing and the proposed on different layers because they are the same object.

You do have the option of creating a 'SnapShot' of the Site Model and placing it on a separate layer but this is unrelated to the Cut and Fill calculations and you shouldn't think of the Snapshot as being a different Site Model - as it remains linked to the originating Site Model. It's more like a design layer viewport for Site Models although it as some added capabilities and limitations.

With Vw 2009 Site modifiers (such as pads) gained the option of affecting the 'existing' portion of the Site Model. This is a setting in the modifier and you set it using the Object Info Pallet. It will affect the result of a cut and fill as ... if the modifiers are all modifying the 'existing' then there will be no cut and fill. Alfresco is using 2008 so he won't see this.

Also with 2009 the cut and fill calculation got a lot more accurate at the expense of speed. With 2009 instead of being calculated everytime the Site Model was updated, it calculates only when the 'Calculate Cut & Fill' Button on the Object Info Pallet is clicked. (Be aware that you have to have the site model selected to see this option. ) Again in 2008 alfresco won't see this.

islandmon - you are correct that 'That's how the DTM Procedure was originally set up." but ... it doesn't work that way anymore and hasn't for some time, so if alfredo is using 2008 like he says this doesn't apply.

I should also add alfresco, that if you do create two site models - you won't get a cut and fill because to calculate it the site model needs to have both the existing and proposed in the same object. So create an existing site model, add pads and modifiers, update it and you should see a cut and fill, regardless of whether the actual site model is displaying the existing or the proposed...

Edited by dspearman
Link to comment

dspearman - agree with all of that

The Site Model Tool enters very complex territory but is also very powerful - on a recent prject it amazed me what it can achieve

I created one Site Model - Existing and then another Proposed to consider some cut volumes for batters and road levels which had to be considered as Civil Work Expenses.

From the Proposed I extracted data; created a new Site Model - New Existing - and then used all of my proposed landscaping levels - New Proposed (final Landscaping) to gain cut volumes for landscaping works

It worked and worked well but is was painstaking

We have options when creating a Site Model to get rid of original data (I needed that for documentation purposes) or to gain data from the Site Models Layer or all Layers (my existing Data I Classed and put on a different Layer and told the site Model / Models to live on their own seperate layer / layers

Whilst it all worked and amazed me what could be achieved the Site Model Tool really needs to be made into a much more intuitive and user freindly Tool

Later with 3D Mesh boulders, Texture Pads, Image Prop trees I produced a rendered 3D model of the finished landscape - a recreation reserve

All the way through the project I exchanged my data with the engineers

Proved to me that persisting with VW leads to being able to achieve great things

The Site Model Tool combined with roads, and other tools can do with some really clever software development

Link to comment

Hi Ozzie,

You might consider next time to create one site model and have a 'snap shot' to show the existing. It's simpler and you don't get the annoying dialog asking where site model a stake should apply to.

I find things go much smoother for me if I limit myself to one site model in a file. If you really need two site models keep them in separate files and use design layer view ports to reference them to a third.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...