• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

necessary pipe cover

stumpjumper83

Senior Member
Joined
Jan 13, 2007
Messages
1,974
Location
Port Allegany, pa
Occupation
Movin dirt
I'm goign to be doing a stream crossing on some property that I own and I'm planning I using a stick (20') piece of black abs storm sewer pipe for it. Diameter of the pipe will be either 40" or 48". What I'd like to know is how much cover I should be topping it with. The intention is to build to strong enough to drive an loaded semi across. Fill will be mainly flagstone scraps from a local quarry. And I'll bed and cover the pipe with #2's probably.
 

CM1995

Administrator
Joined
Jan 21, 2007
Messages
13,250
Location
Alabama
Occupation
Running what I brung and taking what I win
First of all check your prices on pipe, they are going up faster than a bank account of a oil futures trader.

I am bidding a cell tower access road that has 18", 24" and 30" ADS piping. Called to get current pricing and was told it is increasing 10% in August and may go another 10% in September, they don't know after that.:beatsme Makes it a little hard to bid.

My experience with ADS and other plastic pipes of these sizes, the performance of the pipe is all in the quality of the installation and the bedding/backfill material. My suggestion would be to look at the manufacturer's spec's for backfill material - under, around and top.

For ADS piping I like to use #57 stone as bedding and either #57 or #8910 as side and top backfill. The smaller #8910 seems to seat well around the spring line of the pipe and leaves less voids. I would not use sticky clays or any large pieces of rock < 3/4"-1" as bedding or backfill directly around the pipe.

Of course this brings up the other question about the smaller stone's susceptibility to washing due to the fact it is a stream crossing. Are you putting any headwalls around the ends of the pipe?
 

stumpjumper83

Senior Member
Joined
Jan 13, 2007
Messages
1,974
Location
Port Allegany, pa
Occupation
Movin dirt
Yes I'm headwalling with cut ssandstone or 8" flagstone in 4' x 4'. I've located the pipe as leftovers from a developement for a good price. I don't recognize your stone numbers cm, what diameter screens do they use for that stuff?
 

CM1995

Administrator
Joined
Jan 21, 2007
Messages
13,250
Location
Alabama
Occupation
Running what I brung and taking what I win
Sorry for the confusion, you get used to dealing with the regional terms for items.

#57 stone is 1 1/2-inch-minus and #8910 stone is 1/2 inch-minus with more stone dust. The stone size gets smaller as the number gets higher - clear as mud?:confused::D

We use #2 stone for construction entrance's and bridging wet areas, it should do well as the traffic surface in your situation. #57 stone is the most used stone for us. It is used for underslab gravel, driveways, foundation backfill, pipe bedding, etc. The #8910 stone does well for flat driveways and trench backfill, some City spec's call for #8910 backfill in road cuts around here. Although I don't like it for pipe bedding as it does not self consolidate (needs to be compacted) like #57 stone will.
 

TriHonu

Well-Known Member
Joined
Apr 17, 2007
Messages
139
Location
Minnesota, USA
I was just researching this same issue last week. For corrugated plastic pipe I believe you will find 12 inches (300mm) the minimum cover. Bedding, fill and compaction are the sources of most failures. The NCSPA Installation Guide page 39 has a couple charts that detail how much additional cover is required for increased axle loads.


Here are a couple of documents you may find helpful.

National Corrugated Steel Pipe Association Installation Guide (PDF 412k)

Handbook of Steel Drainage and Highway Construction Products (PDF 13 meg)

Concrete Pipe and Box Culvert Installation (PDF 2.3 meg)

Blue Diamond Website High Density Polyethylene Pipe (HDPE) Installation

Iowa DOT Drainage Specifications

Ten Rules of Thumb for Culvert Crossings Erosion Control Magazine

Culvert Use, Installation and Sizing Low Volume Roads Engineering Best Management Practices
 

Attachments

  • SteelCover.jpg
    SteelCover.jpg
    81.6 KB · Views: 669
Last edited:

Dirtman2007

Senior Member
Joined
Sep 30, 2007
Messages
1,202
Location
Raleigh, North Carolina
Occupation
Heavy Equipment Operator
First of all check your prices on pipe, they are going up faster than a bank account of a oil futures trader.

I am bidding a cell tower access road that has 18", 24" and 30" ADS piping. Called to get current pricing and was told it is increasing 10% in August and may go another 10% in September, they don't know after that.:beatsme Makes it a little hard to bid.

My experience with ADS and other plastic pipes of these sizes, the performance of the pipe is all in the quality of the installation and the bedding/backfill material. My suggestion would be to look at the manufacturer's spec's for backfill material - under, around and top.

For ADS piping I like to use #57 stone as bedding and either #57 or #8910 as side and top backfill. The smaller #8910 seems to seat well around the spring line of the pipe and leaves less voids. I would not use sticky clays or any large pieces of rock < 3/4"-1" as bedding or backfill directly around the pipe.

Of course this brings up the other question about the smaller stone's susceptibility to washing due to the fact it is a stream crossing. Are you putting any headwalls around the ends of the pipe?


I find it interesting that you use rock around you pipe. Out of all the 1000's of feet of that stuff I've layed I've only used gravel under it a couple times as it was going through some wet areas. Seems like the water would just leach around the pipe instead of going through it if used for a stream crossing. I just dig out the creek channel to grade roll er in there and backfill with clay, using the skid steer to pack it.

If the dirt is real good 12- 16" of cover is good for a 48" pipe, but there more the better. Just remember teh more cover the narrower your path is going to get! 20' of pipe with 3' of cover can lead to a driveway only being 11 or 12' wide by the time you slope the sides.

If I remember correct 48" plastic pipe is getting close to $30.00 a ft. maybe more:beatsme
 

Sharky

Well-Known Member
Joined
Aug 3, 2008
Messages
97
Location
Juneau Alaska
With a properly bedded and compacted fill around the pipe, 1-2' of cover is sufficient, We have installed some with as little as 6'' of cover, and years later they are fine, however others with 3-4' of cover, I have seen semi-collapse. Proper compaction around the pipe supports the structural integrity of the pipe. Use no large rocks within 4' of any top portion of the pipe, those will cave it in as well if a heavy load crosses it.
 

tuney443

Senior Member
Joined
Mar 19, 2006
Messages
1,216
Location
Dutchess County,NY
Occupation
excavating contractor
With a properly bedded and compacted fill around the pipe, 1-2' of cover is sufficient, We have installed some with as little as 6'' of cover, and years later they are fine, however others with 3-4' of cover, I have seen semi-collapse. Proper compaction around the pipe supports the structural integrity of the pipe. Use no large rocks within 4' of any top portion of the pipe, those will cave it in as well if a heavy load crosses it.

X2---just like anything else,your top is what your bottom is.In other words----------COMPACTION--at least up to the spring line.Around me,lots of guys will literally just throw any type of pipe in the ground and backfill with the spoil,no matter how poor it might be.I'll lose a job to that nonsense,but that's life.I'll take clients that appreciate a good job and are willing to pay a fair price.My Dad used to drive everyone absolutely insane in that he demanded perfection-----at the end of the job he would shine a powerful flashlight beam into the end of the pipe and he'd want to see a PERFECT circle exposed come back to him.As for ADS pricing,a 20' lenghth of 30'' back in June was $600 by me.I'll bet concrete pipe isn't even that much now,but we do live now in a plastic world---literally and figuratively.
 
Last edited:

stumpjumper83

Senior Member
Joined
Jan 13, 2007
Messages
1,974
Location
Port Allegany, pa
Occupation
Movin dirt
well turney443, I was able to get a leftover piece of 48" for a little less than you have on that 30". I wanna build up the areas on either side pretty good. In this set up, I wanna be sure that I get good compaction on either side of the pipe. Its alot harder for the pipe to colapse if the sides cant push out. Maybe i'll get up there sometime and take some pics for you all.
 

F-1.08-F.G.

Active Member
Joined
Mar 17, 2008
Messages
27
Location
Richmond VA
Sorry for the confusion, you get used to dealing with the regional terms for items.

#57 stone is 1 1/2-inch-minus and #8910 stone is 1/2 inch-minus with more stone dust. The stone size gets smaller as the number gets higher - clear as mud?:confused::D

As far as the numbers go at the quarrys... #57s are comprised of a combination of #5s, #6s and #7s (excluding the 6s for simplicity) and the #8910s are a combination of... you guessed it, #8s, #9s, #10s. Why they exclude the middle number in #57s but not #8910s... don't know:beatsme:idontgetit
 

Big Iron

Well-Known Member
Joined
Oct 16, 2006
Messages
219
Location
Oregon
Occupation
Project Manager
general rule of thumb is a minimum 1/2 the diameter of the pipe for cover or manufactures recomdations. More is better. Chink (forcing the rock under the bottom 1/3 of the pipe) the underside of the pipe well. No the rock will not act as a conduit for water if properly compacted from top to bottom (this is where chinking comes in).
 

stock

Senior Member
Joined
Aug 4, 2008
Messages
2,022
Location
Eire
Occupation
We have moved on and now were lost....
I think I stay over here as I just got used to 804, 6n, 6ni,6p,1c ,505, 503 etc.On our jobs we would first check the ground, chould use a CBR test,but a rule of thumb is if your heel leaves a mark deeper than 25mm it is too soft so I would excavate deeper fill with 1c to 100mm - 300 below invert (pipe size dependant) then use 505/503 chip as a bed, settle the pipes to level and put more chip/ shingle around your pipe haunched up with 6n to a slope of 1:1, and where cover is scare use a lean mix concrete after that, 1/2 dia pipe cover min, to formation level .All stone to be put in inlayers of 150mm max If being compacted with a whacker plate of suitable size or, 300mm with a 1.2m roller,it is really important to bring up your levels all at once,shingle 6n 2c to mentain compaction,as an antiscarrifing measure settle your wing walls on concrete or use hand picked 1c in concrete ....sounds difficult not really
 

AtlasRob

Senior Member
Joined
Feb 8, 2008
Messages
1,982
Location
West Sussex UK
Occupation
owner operator
I think I stay over here .......... ....sounds difficult not really

:eek: Know exactly what you mean Stock. Shingle over here is pretty easy 10mm, 20mm, rejects > 40mm, all in ballast = sharp sand and 20mm mixed, BUT then you get to 6f2, scalpings, MOT type1 and all the other types for different uses. Lucky I just have to place it not order it :D

Talking of headwalls do you boys in the States use sand bags filled with a dry concrete mix at any time ? Stupid question really you probably invented the idea ;)
 
Last edited:
Top