Best way to draw/design existing utilities?

[mhvam06]

Hello everyone,

I am encountering issues in regards to drawing/designing existing utilities.

Here's my best way to do it... however there's a major issue with this solution. It is VERY slow upon completion. I think it might be because of a lot of null structures.

• Create existing surface from surveyor
• Create Feature Lines from object (existing utilities are polylines)
• Assign elevations from surface. Check Insert Intermediate grade break points
• Move elevation point to surface (Elevations from Surface)
• Lower Feature line by 500 mm if the needed cover i 500 mm.
• Create Pipe network from object
• Select feature line and use outside top
• One pipe network is created per feature line
• Merge pipe networks to 1 network for final setup

Is there a better way to do this?

I'm about to do a model with approximately 50 kilometers of pipes (in different types utilities). I hope someone can help to make it as smoothly as possible.

I will be create in a file for each utility type and I will also be using Data Shortcuts for the collaboration.

Best regards

Mikkel

[M_c3d]

This is just my opinion...but why are you modelling existing utilities?

The approach I take is that you model what you are connecting to, i.e. an existing manhole.

Any other utilites should be a CDM risk on your drawing saying that there are existing utilities in close proximity and refer them to GPR survey or utility plans.

If the recommended depth is 500mm below ground level, how do you know without an accurate GPR survey that they were installed 500mm below ground level? In my experience, a contractor does what they like on site and the chances they will be exactly 500mm below is slim at best.

I also don't think they would jump a cable or gas pipe up to suit a slight increase in ground levels. More chance they would do it at a constant level or gradient.

If you put that kind of accurate information on a drawing that you are not 100million% sure about, then you become liable. It's a risk i wouldn't take.

Civil engineers aren't responsible for services, this is a services engineer. (assuming you are civil)

[mhvam06]

Thank you for taking time replying to my post!

I probably should have explained the assignment in another way. Actually the utilities are not existing.

In an earlier phase of the project all centerlines of the utilities were designed using Polylines. Now we want to upgrade the level of information to 3D.

The reason why it was not designed in 3D in the first place is because I find major changes to 3D-Pipe networks very time consuming.

Therefore I did them in 2D first. Also because the future elevations of the project were not set in stone to begin with.

This is the reason why I explained it as "existing" even though the utilities are actually not existing.

[civilman1957]

I agree with @M_c3d. Modeling existing utility lines is not only risky, it's unnecessary. If we having either storm drain or sanitary sewer lines crossing our designed pipes, we will model whatever existing lines are crossing ours, in order to show the crossing in profile view, but not the whole system. By notating the rim and inverts in the existing system, you are letting the reviewing agency/contractor know it's there, and how deep.

With water/electric/gas lines with an arbitrary depth, we will model a short length of it, again to show in profile as a crossing, but will also note on the plans that depths are assumed based on design criteria, and the contractor is to field verify the depth before performing any work in that area.