Attaching 36'' Plastic Culverts

[Doxiegals]

Don't worry about the different spirals and a tight connection.

The problem you had was caused by digging a narrow trench to put the original culvert into. Fill material could not get under the bottom half of the culvert. So it created a vacancy that eventually filled itself. It did so by crushing the culvert.

Never bury a culvert in a tight fitting trench. Always have at least 50% of the culvert width of open trench on each side. So for a 36" culvert you needed at least a 72" trench. This allows fill material to be place under the bottom half of the culvert. Even with this situation you will still see some "egg shaping" of the culvert. But it won't affect the volume flow of the culvert.

Fill material is irrelevant. I never use anything but dirt.

I work for a Township and over the past 25 years have buried hundreds of road culverts. I've never used special fill material. I always want an open trench so I can get material under the culvert. Once I get some under it, I pack the snot out of it with the Road Grader. It will always settle. You can't stop that. Just expect it.

Good luck with your project.

I think you hit it on the nose!! The problem happened orginally as we could not find any way to stop the flow of water when installing the culverts.The correct way would have been to dig a 200' ditch along side of the permanent culvert,which would have been a disaster, but !!
If I had to guess I would say there was approx 6'' of water to deal with while installing. When installing it the second time we still had some water but less and we did try to lay class 5 under the culvert but not sure how much of a void is under it?
So I guess time will tell.
Thanks For Your Help

 

[/pine]

FWIW...Some types of pipe/culvert manufacturers make what they call "diapers" for securing pipe joints with concrete...I've seen them for up to 42" pipe...

 

[Jim Timber]

What you should've originally done was fill and compact the base where the culvert trench was, then dig the trench and place the culvert in it, then top fill with base material and compact it.

If you have water flowing in the ground under the existing culvert, you're going to wash out your base again. It's just a matter of how long.

When we put the culverts over my swamp, the ground was still frozen under part of it. When the ground thawed, the culvert wasn't as well supported and had some give with a 10,000# axle weight. Then a flat bed driver managed to drive off the road right on top of that culvert and bent it 45 degrees. So we ended up doing a better base job under the sloppy side when repairing that FUBAR.

 

[Jim Timber]

He was way off, and I made the "not awake yet" bad decision to not insist on spotting him. Had I been on the ground guiding him in, I'd still have a slightly soft culvert.

He's standing where his left tires should've been.

 

[pat32rf]

looks pretty narrow anyway for the drivers around here...

 

[Jim Timber]

It was tight, there's no doubt about that. But it was passable and we had a 42,000# truck on it this spring when it hadn't settled in nearly as much as it had when the rollback was going over it. I made the driver walk the whole route before loading up the container to make sure he was ok with the clearance and he claimed all was fine.

2 days later I had my guy bring 2 more loads of tailings and I widened it out a bit. We moved the container across 3 days after that, and then they came back with a new culvert 2 days after that. It was quite the week! :laughing:

I'm still not even close to my permitted width, but I know there's probably going to be a fair bit of settling with the first winter freeze/spring thaw cycle. So I just made it useable for the first year and will add more as things shift and settle. The swamp peat is between 2' and 4' deep down to clay and then 4" below the clay surface is beach sand, so I chose not to put geotextile down in favor of retaining the root matt.

 

[kevin37b]

Am a bit confused . Did he drop off with container on ? Truck drivers are probably the worst about on the phone instead of on the road . Looks like it should have been a rollover .

 

[Jim Timber]

I made the executive decision to get the container off before they tore up the side of my road any more trying to un-stuck the flatbed. 5500# that high up makes a heck of a lever to pin the low side of the chassis down. We had tried (unsuccessfully) to use the side winches and the outrigger, and stinger to level the truck on the shoulder and all they did was mash up the compacted fill and drop the truck lower yet.

This truck couldn't budge it, but proved a cargo container makes a great drag!

This is what eventually got that truck out of the swamp:

Sorry for derailing your thread Doxigals.

 

[kevin37b]

Interesting , 72 " hole for 36 " culvert ?

 

[pmsmechanic]

Here is what we used to do to attach mismatched culverts.

This used was mostly in low flow areas but what you don't want is water running under the culvert. If it starts to swirl at the joint it will wash the dirt out.

We just wrapped the two ends with a good heavy plastic. If leakage was a concern we would wind a rope around several times and pull it tight. It wasn't perfect but it worked. Make sure the bottom of the joint is on compacted dirt. Ideally the dirt should be compacted in 4" lifts on each side of the culvert making sure you get the dirt under the bottom half of the culvert. If a compacter wasn't available we mix a thick slurry of mud and use the backhoe to push the mud where to compacter couldn't reach.

We didn't make the hole twice as wide as the culvert but we made sure there was lots of room for the compacter. IE jumping jack or what ever is used to pack the dirt.