Trimble Business Center

Something that I have run into is that there does not seem to be a way to modify a takeoff subgrade surface besides applying MSI improvements to the finish grade surface. This works well for "sites" but the downside to this is that you will only get vertical faces, you cannot get sloped subgrades.

There are many cases where this is not correct such as the subgrade for a roadway, subgrade for building E&B, leach beds, underground detention systems, and  MSE walls. And truthfully real life applications. The typical may show a vertical face but it is pretty hard to build a vertical face in a fill. Therefore there will be waste and it should be taken into consideration. A lot of these calculations have to be performed separately. Sometimes separate calculations are necessary, but sometimes I feel it is because there is not a better way off running the calculations.

You could model the subgrade surface manually but unfortunately there is no way of replacing that with the automated surface. Maybe if there was a way to add a bound and designate an area that will deviate from the traditional vertical subgrades. This area could be composed of entities such as side slope lines, corridor components or manual modeling and allow the user to add entities to subgrade surfaces similar to how the can with the finish design surface.

I have tried to model the subgrade of a roadway and blend this into the takeoff subgrade of the rest of the site but have not found a way of doing so and have the takeoff report reflect this hybrid subgrade surface. There are ways of obtaining the values but they require multiple methods and compiling multiple reports to get results.

One work around is to:

1. Model the corridor; finish, select layers, and subgrade
2. Apply the subgrade surface to the finish design surface instead of the finish surface
3. Do not apply any MSI values within the corridor bound
4. Run the takeoff report to get the mass earthwork and selects outside of the corridor
5. Run the corridor takeoff to get the roadway select values

Is there something that I am missing to accomplish a hybrid subgrade? If not, would it be possible to incorporate this in the future?

Ideally I would like to take the attached site, a combination of 2 roadways and some traditionally site grading, and be able to run one takeoff report to get all of my values. 

Thank you!

Pat

This is a big subject and one that I would be happy to get with you on at some point in a couple of weeks time - I am heading out to Montana to do a weeks training next week, and have meetings on and off over the 3 weeks after that - but I will try to find time to call you on this. 

I agree that the Takeoff Surfaces and Subgrade Adjusted Surfaces created by Takeoff are kind of locked down and the Breaklines etc created are internal only so hard to get at - you can Add and Remove Surface Members and Add / Remove Surface Boundaries to Takeoff Surfaces in the same way you can to normal surfaces, so you can maybe block out an area or add some extra breaklines but I think that is a bit limited. The other challenge of course is that you cannot convert a normal surface into one of the Takeoff Surfaces so that it can be used in the computations of Takeoff - at least not today - but these are things that we should be looking at going forwards - for a wide number of reasons.

I haven't watched your video yet, and will try to find time to do so next week once I have completed my prep work for the training class.

In general I get where you are coming from, but worked examples help me to better understand the limitations.

Alan

Thanks Alan. The video shows a couple examples and I will try to compile a few more and throw them on this thread as I come across them.

I know there has been a couple of talks about creating takeoff groups that are complied of sets of surfaces designated by the user.

I will start brainstorming and prepping for your call.