How much tamping required for a culvert?

[buckeyefarmer]

Builder down the road dropped a culvert in an existing ditch without digging, covered with a load of stone. First concrete truck crushed it like a pretzle, ends stuck up 90 degrees in the air. They eventually pulled it out of the ground.

 

[ovrszd]

The last two failures in this thread were caused by the base under the culvert more than the coverage.

Today I'm installing a 36"x60', a 30"x60', a 18"x50' and a 15"x40'. I'll use no fill material other than the existing dirt. I'll use no compaction method beyond the grader tires. Traffic will be crossing them all by evening.

Sure hope they hold up.

 

[Fallon]

Well it's not working at all based on the snow melt the other day. But that was expected until I re-grade the driveway up to my shop & ditch the side.

It's carrying the traffic fine, which is my main concern for now. Needs regrading already as it packs down a bit lumpy, but no surprise or big deal there.

 

[Egon]

Compaction -- Fact or Fiction?

 

[RedNeckRacin]

Compaction -- Fact or Fiction?

100% fact. :thumbsup:

 

[dfkrug]

Compaction -- Fact or Fiction?

That's a great video, EGON.

I am a big believer in compaction. I use a jumping-jack or gas-powered plate compactor.
6" at a time.

It is true that you can get away with minimal compaction, depending on the type of pipe,
its depth and the load. Sometimes just driving on the backfill in 6-12" lifts with a
wheeled machine (tractor, car?) in line with the pipe works well enough. Kinda hard
to do that in a deep trench, however.

I don't use plastic culverts, but they are attractive, if I do another culvert. On my
property, I was subject to inspection, and that often means I have to hire an
inspector to do a compaction test. :-(

I one area, I did not get the 95% compaction required, so I had to dig it out,
add more class II base, and re-compact. Then another inspection.

The guy I hired in the 90s to dig my septic system failed to properly compact
some of my trenches that had 4" poly pipe in them, and they were crushed
to 50% size. These were not the leach line trenches, and poly pipe IS soft.
Plastic is great, but needs proper installation.

 

[ovrszd]

Well it's not working at all based on the snow melt the other day. But that was expected until I re-grade the driveway up to my shop & ditch the side.

It's carrying the traffic fine, which is my main concern for now. Needs regrading already as it packs down a bit lumpy, but no surprise or big deal there.View attachment 506310View attachment 506311

You'll get the grade properly cut and it'll work fine!!! Expect some lumpiness for awhile.

 

[ovrszd]

That video was very entertaining.

Can anyone explain why it is meaningless?

 

[Egon]

That's a great video, EGON.

I am a big believer in compaction. I use a jumping-jack or gas-powered plate compactor.
6" at a time.

It is true that you can get away with minimal compaction, depending on the type of pipe,
its depth and the load. Sometimes just driving on the backfill in 6-12" lifts with a
wheeled machine (tractor, car?) in line with the pipe works well enough. Kinda hard
to do that in a deep trench, however.

I don't use plastic culverts, but they are attractive, if I do another culvert. On my
property, I was subject to inspection, and that often means I have to hire an
inspector to do a compaction test. :-(

I one area, I did not get the 95% compaction required, so I had to dig it out,
add more class II base, and re-compact. Then another inspection.

The guy I hired in the 90s to dig my septic system failed to properly compact
some of my trenches that had 4" poly pipe in them, and they were crushed
to 50% size. These were not the leach line trenches, and poly pipe IS soft.
Plastic is great, but needs proper installation.

Ahh -- yes; that other world where inspectors are present and do what they are paid to do.
The implement wheel packing gets interesting at times. Work on one side pushes the culvert over to the other side. Then switching to the other side the culvert gets moved back and up leaving voids underneath as well as a non linear culvert alignment.
It would seem some folks have not been in a situation where the culvert installation gets done and the base finish & paver follow right behind. No chance to go back and regrade!

 

[Egon]

That video was very entertaining.

Can anyone explain why it is meaningless?

Meaningless?; is this a reference to having no knowledge of basic procedure's???