How much tamping required for a culvert?

[Egon]

I installed my first culvert in 1989. I've never had a failure or washout. In fact I've replaced some galvanized culverts that I installed years ago that have rusted out. I now use dual wall plastic on all but those over 4ft diameter. I've installed culverts in all sizes from 12" to 96" in lengths from 20ft to 120ft. I've never used a tamper or hand tamped. If doing a large culvert I dig the trench double the width of the culvert and place it in the middle. On a small culvert like the OP is installing there's no concern about that. Use whatever method makes you feel good.

So your saying you got all kinds of expierience ehh. From the sounds of the installation expierience you quote it would seem you have never worked on an inspected contract drawn up by Engineers.

My dirt experience started back in about 1966. All while working for a general contractor and on bid pieces of work with quite detailed methods and inspections. Some of the prodjects were fairly large and had well over two hundred personnel on site. All the newest and largest Caterpillar Equipment was also on site.

The length, diameter, type of culvert and buried depth of many of the culverts involved were just a tad larger than what you quoted you have been doing.

My expierience and knowledge of Dirt & it's Working's is limited.

 

[Rustyiron]

A lot of "dirt rules" are regional and some methods/situations will depend on the local soils. Your steps would be different with some red Georgia clay vs some gravely glacial till that I suspect Fallon might have, and might also differ in a shaley "dirt" and the same with sandy or frost prone areas.

 

[Fallon]

Well it's in, burried & driveable. The 2 buckets of pea gravel made for easy packing around the pipe & not really any tamping. I tamped by for & tire in 6" lifts or so over the top. I failed to crush the pipe driving over it with only 6" of cover.

I'm sure it will be settling for a few years, but I grade the driveway a couple times a year anyway. Need to get a couple truck loads of gravel on it anyway. Also need to sculpt the inlet & outlet a bit. Also re-grade my shop driveway & get water running down the other side & towards the new culvert.

Will try & get photos in the morning if it's not snowing.

 

[ovrszd]

So your saying you got all kinds of expierience ehh. From the sounds of the installation expierience you quote it would seem you have never worked on an inspected contract drawn up by Engineers.

My dirt experience started back in about 1966. All while working for a general contractor and on bid pieces of work with quite detailed methods and inspections. Some of the prodjects were fairly large and had well over two hundred personnel on site. All the newest and largest Caterpillar Equipment was also on site.

The length, diameter, type of culvert and buried depth of many of the culverts involved were just a tad larger than what you quoted you have been doing.

My expierience and knowledge of Dirt & it's Working's is limited.

As I said, do what makes you feel good. Just making it clear that the exact "letter of the law" does not need to be applied to the OP's situation.

 

[ovrszd]

A lot of "dirt rules" are regional and some methods/situations will depend on the local soils. Your steps would be different with some red Georgia clay vs some gravely glacial till that I suspect Fallon might have, and might also differ in a shaley "dirt" and the same with sandy or frost prone areas.

Exactly. That's why rules that are quoted in a governmental statement may or may not apply to the current situation.

 

[ovrszd]

Well it's in, burried & driveable. The 2 buckets of pea gravel made for easy packing around the pipe & not really any tamping. I tamped by for & tire in 6" lifts or so over the top. I failed to crush the pipe driving over it with only 6" of cover.

I'm sure it will be settling for a few years, but I grade the driveway a couple times a year anyway. Need to get a couple truck loads of gravel on it anyway. Also need to sculpt the inlet & outlet a bit. Also re-grade my shop driveway & get water running down the other side & towards the new culvert.

Will try & get photos in the morning if it's not snowing.

Excellent. Yes, the use of pea gravel will minimize need for packing and will give a uniform amount of pressure on the culvert. I've buried many with less than 12" of cover and with any consideration they holdup to immediate traffic with no failures. Congrats on a successful install.

 

[flusher]

Here's how mine was installed in April 2005. Professional job. No problems.

 

[ovrszd]

Here's how mine was installed in April 2005. Professional job. No problems.

/QUOTE]

Excellent!!! I want to pave my driveway so bad......

 

[s219]

It's old, but here's my culvert thread from about 5 years ago:

http://www.tractorbynet.com/forums/projects/235661-putting-entrance-culvert.html?highlight=

When I talked to the county, they told me about Virginia DOT (VDOT) specs for culverts in terms of pipe size (based on 10-year-flood rainfall), pipe bedding, and cover over the top of the pipe. So that scared me into doing it by the book. I noticed in the years since, most builders simply plopped down a concrete pipe right on top of the grass and then filled over the top with whatever they had and started driving over the top with construction traffic. When VDOT took over the road in 2015-2017 (they are just completing the process), about half of those properties had to redo their culverts! Some of them had already put in concrete or asphalt over the pipe, so it was a big project. There were some dumb mistakes, like not enough cover, pipe inlet too high above the bottom of the ditch, bell opening on the wrong end (needs to be on the uphill side), etc. Talk about stupid. So in the end I was glad I did it right the first time. Back then I was a complete tractor newbie with a teeny little tractor and I still did better than the pros. I guess they just wanted a construction entrance and never bothered to upgrade it to final specs.

The other thing I noticed back then is everyone I talked to really was skeptical about using plastic pipe, but all my research had shown it was far superior, easy to handle with one person, and should outlast me. The trick is that you absolutely need proper cover with plastic, as it's the arch of stone/gravel/fill that carries the load.

I think most building contractors choose concrete because they can drop it in the ditch and drive over it with minimal cover. But all the concrete pipes on my street have chipped ends and look terrible. One guy used galvanized pipe, and it has held up pretty good, albeit with a few dents on one end.

A few years after I put in my pipe, I dug out the ends and added another 5' to each end to widen my entrance. That was a piece of cake -- just used soapy water to lubricate the o-rings on the spigot ends and tapped the bell ends on with a hammer and block of wood. Another reason to like plastic.

 

[ovrszd]

I agree, much prefer plastic. Only downfall in rural applications is they will burn easily. 3 times in the last 20 years of using plastic farmers have burned them out while burning off CRP land in the Spring. Once that pipe gets on fire there's no putting it out. Melts down completely and all the way from end to end.....