Why does Civil 3D design to the center of the structure

[cwintermute]

Civil 3D 2010

Why does Civil 3D design to the center of the structure? (for inverts)

The reason I ask is because our office designs to the edge of the structure wall (for invert elevations).

Is designing to the center of the structure (for invert elevations) an acceptable way of designing?

If it is an acceptable way of designing, then it's going to be a matter of convincing our engineers to start designing to the center of the structure instead of the inside edge of the structure wall. Any tips on how to convince them that this is acceptable. (some of them are set in their ways).

Thanks,

Chris

[jmeyer.186809]

Civil 3D 2010

Why does Civil 3D design to the center of the structure? (for inverts)

The reason I ask is because our office designs to the edge of the structure wall (for invert elevations).

Is designing to the center of the structure (for invert elevations) an acceptable way of designing?

If it is an acceptable way of designing, then it's going to be a matter of convincing our engineers to start designing to the center of the structure instead of the inside edge of the structure wall. Any tips on how to convince them that this is acceptable. (some of them are set in their ways).

Thanks,

Chris

well are all your stuctures for your projects pre cast? it doesn't leave the contractors much room for play if something has to change or the box has to be moved or slide, lowered or raised. We always calc to the center of the box so that it's easier for everyone to build the project.

[jpaulsen]

We feel you pain. We design to center of manholes and the inside edge of inlets (catch basins). An average size for a Type R inlet is 10' and they can be as much as 30' long. Thats a lot of extra pipe if we calc to the center. Another issue with always going to the center is with a 10' long inlet the pipe does not have to enter at the center of the wall. Many times it is offset.

I believe we are using null structures at the wall to make the pipe lengths correct then a small section of pipe to the center of the structure. If I am wrong I will ask one of our Pipe experts to post our workaround.