Hi again guys,
Apologies for the long backstory to get to my question...

I had to change grade to get slope for surface drainage for my driveway a couple years ago.
As a result the exterior 4" sewer line is now only about 8" below grade at the shallowest.
It was a gravel drive and I've been driving across it for the past couple years with no issue.
Now I'm putting concrete in so excavated 4" of gravel to allow for 4" concrete to get to same elevation.
The pipe is now broken at the high end where it goes under my rock retaining wall which is 2' tall and then under the house.
Either the weight of the skid steer or the vibraplate compactor apparently crushed/broke it.
It is the thin green sewer pipe they sell here for outdoor sewer line.
The concrete contractor says pouring conc over it will add weight and crush the pipe again.
He also says things that are not accurate so I don't trust completely his knowledge.
I say pouring concrete over it will protect it and bridge across the 4" span of the pipe itself and rest on the compacted subgrade each side of the pipe.
If I could drive over it when it was just gravel I'm sure concrete will be even more protective.

The Question:
Is there anything I can do to protect/strengthen the pipe?
Is there rubber pipe like fernco that would bend but not break if excess weight was applied in future?
Extra rebar across the area of the pipe?

Should I dig up the green and replace with sch40? I don't know why they use the thin green here instead of heavier pipe, but that's what I got talked into several years ago when I took out the broken clay and replaced with this plastic on the initial regrading project.

He's scheduled to pour tomorrow so I've got to do something quick...in addition to fixing the current break.
I'm stressing...

you may NOT, repeat NOT, encase the sewer in the driveway

the sewer must EITHER


run UNDER the concrete

or

be agequately 'sleeved'

or

be protected by some sort of 'vault'




delay the pour until you have the issue resolved





you may very well REQUIRE a gravel drive

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

just run cast iron pipe you'll be fine.
P/S, cast iron should have been used in the first place.
have whoever does the job use extra heavy (XH) single hub bell and spigot pipe with rubber gaskets to seal the joints.


the gaskets look like this.

A couple of things.

Down where we are driveways need to be 6" thick. Also you need a compacted gravel base under the concrete so just excavating 4" for concrete will not be enough. You need to excavate more to build up with different aggregate bases to the bottom of the concrete.

You are saying the shallowest point the pipe is 8" below proposed finished concrete? or 8" below bottom of concrete? Does it mean the pipe will have 4" or less of fill under the concrete or 8" of fill?

I would take a different approach.

(1) Install 2X forms across along both sides of the pipe, leaving a 10"-12" wide gap with the pipe in the middle, exposed.
(2) Drill holes in the form on both sides to pass 5/8 or 3/4 rebars across the gap, with the rebars extending at least a foot or two into the soon to be poured sections. Do one rebar every 6 to 8 inches, then cross tie them inside the forms with another one or two rebars on each side. Set the rebars 2/3 down the concrete depth.
(3) Pour concrete as planned tomorrow. Leave the gap unpoured.
(4) After a few days, remove formwork, those pieces along the pipe gap has to be cut out since the rebars will be in the way.
(5) Moisture cure the concrete cover with tarp and wait 28 days for the concrete to get to full strength.
(6) You can decide later, if you want to fill the gap with gravel, or fill it up to 4" then just pour that gap. If you pour that gap, the concrete on both sides will already have set and strong, and the rebars will help with the section of concrete between the edges.

Something like this.

Thanks everyone for your responses.

fwiw

This is what I got from an engineer buddy.

nice vault



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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638