RCP Storm Drain Installation - limited vertical clearance 4

[RussellCE]

Hi All,

Developer is designing an apartment building that spans over a shallow (2-3' cover) City 33" RCP storm drain within a 20' wide easement. The proposed design has no building or foundations within or surcharging the easement or pipe. The City is asking for a 30' vertical clearance within the easement so they can get a crane in to replace any segments of pipe in the future. Current design only provides 9.5' vertical clearance - providing the full 30' height kills the project. I'm researching other methods of installation of this pipe - bobcat/fork lift etc. that doesn't require as much vertical clearance. Pipe comes in 10' segments that weight ~5,000 lbs each. Any advice is greatly appreciated.

Thanks,

Robert

 

[TigerGuy]

1-Talk to your local contractors and see what they would do in that situation.
2-Incorporate a gantry crane in the building design along the pipe alignment. (Somewhat sarcastic on this one)
3-Replace RCP with 30" PVC? The replacement, if ever needed, can maybe be jacked and bored into position.

 

[JedClampett]

We've had whole projects (our portion of the project) where we rerouted storm drains (actually large water lines) for future office buildings. Whoever laid out the project should have considered the easement. If you can't reroute the pipe, you might have some bad news for the developer.

 

[coloeng]

It sounds like someone should have contacted the City about the easement prior to designing something that only allowed 9.5 ft of vertical clearance above the easement.

For replacement in the future, sliplining could be considered, as long as the existing RCP doesn't have major deflections in the joint.

 

[TigerGuy]

Jed is correct. The line needs to be re-routed to outside the building footprint. I can't imagine the developer will ever get a building permit for this.

Of course, we once looked at a home to potentially purchase where the sun porch was constructed directly over the septic tank. So, you never know what will be approved for construction. Needless to say, we continued our house hunting elsewhere.

 

[1503-44]

Load and Height is not the problem. 20ft width is tight, but not impossible.
583

https://www.ritchiespecs.com/model/caterpillar-583t-crawler-pipe-layer

https://plmcat.com/pipeline-equipment/pipelayers/pl61-pipelayer

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[RussellCE]

Thanks for the input everyone. Pretty great community here...

There is a lot of history on the project, several years of design and coordination but this issue slipped through the cracks. I just got brought in the project recently to try and clear this issue, as it's the only thing holding up pulling building permits (previous civil is no more - this is due diligence/SD stuff for us).

Re-routing is not an option without a full redesign of the building, which is what we're trying to avoid.

I'm currently in contact with a lot of local contractors and crane operators trying to confirm there is a way to replace/install with the 10' vertical clear. This is what the developer tasked me with - trying to find evidence the 30' they're asking for is nonsensical so the City will sign us off. But from what I'm hearing there doesn't seem to be a standard practice way to install this heavy of a pipe without a crane/excavator to sling and lower it in the trench, which will require the ~30' clear.

We've looked at PVC/HDPE pipes, the pipe manufacturers will not bless the product to be run underneath buildings and I doubt the City will approve this (looking into this more, since we're not really under a building - no footings or surcharge in the easement).

Keep the ideas coming and I'll keep you all updated.

 

[1503-44]

They just want to do it the easy way.
Custom booms can be fabricated for shorter overhangs and would not require 30ft height.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[SWComposites]

Install walls on either side of the pipe; put rails on top of the walls. If pipe needs to be replaced, rig up a car on the rails, slings to hold the pipe, then move the car down the rails into position, lower the pipe into place.

 

[udraft]

All these solutions are nice, but it seems you need to get the City to go along with the build. Just offering a solution may not satisfy.
Proposing a structure in an easement is just a bad idea. You're kind of at their mercy without some sort of pre-approval.