In this post I will explore how to handle Demolition Areas on Existing Ground using the Takeoff Work Processes.
The Demolition Areas are applied as Site Improvements to an Existing Ground Surface Model. Demolition is removed from Existing along with Topsoil Stripping to create the Original Ground Surface to which Earthworks Computations are made.
Note that your topsoil stripping boundaries need to exclude your demolition areas since you will not be stripping and demolishing in the same areas - take your topsoil stripping boundary and your demolition areas and use the Track Region Outline command to find the boundary line(s) that run around the limits of your stripping and that run around all of your demolition areas. Use the track interior regions function of the command to derive the appropriate result.
The steps to create Demolition Areas are as follows
- Create the Existing / Original Ground Linework for the project on a set of layers - maybe in an Existing Ground Layer Group that start with a prefix OG - XXXX etc.
- Categorize the Layers using the Takeoff - Categorize Layers function, and assign all those layers that have 3D lines that will be a part of the Original Ground Surface as Original Ground.
- For the Demolition Areas, they will need boundary lines - typically a single polygon boundary, that is 3D that is a part of the Original Ground Model (on a layer categorized as Original Ground).
- In the Categorize Layers function, select the layer(s) on which your Demolition Areas are defined and then tag those layers with the Includes Potential Boundaries flag. This will enable you to apply different depths of removals to each of the areas that you have defined.
- In the Materials and Site Improvement Manager you will need to define the Demolition Materials. They can simply be called Demolition Removal 1, 2, 3 etc. or they can be given more specific names like Demo - Asphalt Removal, Demo - Aggregate Removal etc. The Demolition Materials should be in the Earthen or Earthen Select Category.
- In the Materials and Site Improvement Manager, you will need to create the Demolition Site Improvements. If I want to be able to separate out the quantities for each demolition area on the project, then I would create a different Site Improvement for each Demolition Area - e.g. Demolition Area 1 has Material Layers A and B and those include Materials X and Y (from the Demolition Materials List) and have a thickness of 14" and 12" etc. You only need one material for each Site Improvement, and you can use the same Material in each Area but I would keep the Site Improvement Names separate for those quantities that I want to report separately. All Site Improvements of the same type are grouped together into a single lump quantity in the Takeoff Report, so creating different Site Improvements for each area allows you to break out the quantities as you need them.
- Now use the Identify Site Regions command from the Takeoff Menu to apply Site Improvements to the Demolition Areas on the Original Ground Surface model. As you place the Site Improvement Markers (and I place those on a layer called SITE - SI Markers), you will see a color flood the area bounded by the polygon demolition areas.
- Now use the Build Surfaces Command to build the Takeoff Surfaces. This will build you the Original Ground and the Original Ground with Subgrades Demolished (Site Improvements Removed) Surfaces.
- You can check the results of the removal using the Surface Slicer command to cut a section through the surfaces to see the result.
- Now you can run the Takeoff Report to generate the volumes of the Demolition Materials. The report will look like this (Concise Report) for the Demolition Areas.
The video shows the entire process.