Design of Pipe Sleepers

[GAURAV G]

thread507-374753
Dear Engineers
I am looking for a pipe sleepers design calculations as per American code. Please share if anyone had done sleepers design. I need to submit the design calculations.
In my situation, 20", 4'& 3#3'pipe is resting on pipe sleepers and SBC=40KN/m2. Please help me with the sleeper design.

 

[dik]

Do you have a geotech report? Do you have frost heave issues? or swelling soils? Can the piping accommodate any movement? I've done cable trays that can accommodate movement by using PWF beams on EPDM 'stips' on soil. Where movement cannot be accommodated, I've done cable trenches supported on piles. The earlier thread shows a supporting wall on a strip footing. Are you looking at that type of foundation? Can you support a concrete beam on friction/end bearing piles? Can you locate the loads so the load centroid is near the middle of the supporting structure? That's pretty simple to design and construct. What if any restrictions do you have?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[GAURAV G]

Yes I do have soil report where SBC is very low 40KN/m2. Yes I am looking for Strip type foundation. Attached screenshot. NO piles allowed.

 

[LittleInch]

Nothing attached.

Key issue is normally how far above the ground is your pipe bearing to avoid overturning.

Which "American Code"?

What sort of spacing? a 20" pipe can withstand a lot bigger separation than 3" pipes.

Did you men 4" (inch) and not 4 feet? pipe?

What loads have you got from the piping guys? Is it simple sliding support or does it need to take axial loads?

What's your FOS on settlement loads?
Does the ground behave itself under constant load ( it's not peat or some other horrible soil is it?)

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[GAURAV G]

Great Thanks for the reply LittleInch.
1. Pipe is 0.3m above ground level.
2. ACI 318 Code
3. Spacing is 500mm end to end pipe
4. its 4" inch & 3" inch pipe
5. Load for 20"pipe=22KN and load for 4"& 3"= 1.5KN/m2 from piping guys
6. FOS=2
7. its not horrible soil SBC= 40kn/m2 only this I know

ATTACHED IMAGE

 

[1503-44]

You will have to add any anchor or friction loads from the pipe. Talk to your pipe stress boys.

Typical isolated footing design to ACI-318 I trust you can adapt this to holding up some pipe. There are usually some kind of embedded plate on top of a grout layer to support the pipe itself, Check with your pipers for their pipe bearing support requirements.

https://skyciv.com/docs/skyciv-foundation/isolated-footings/verification/isolated-aci-318-14/

Come back if you have any additional questions. A "sleeper" is normally just a ground beam, without an underlying footing. If your frost depth, load and stability are OK without the footing, of course you would not need to add it. Just build a sleeper.

Other links you may find useful.

https://duckduckgo.com/?q=aci+318+footing+design&t=brave&ia=web

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[GAURAV G]

Thanks for your reply.

So What I understand is:
Case 1: I can design this as a isolated footing applying additional anchor loads from pipe stress boys.
Case 2: As a ground beam with all loads & check for depth & stability.

Correct me If I am wrong.
Thanks

 

[HTURKAK]

.....

No.. not really.. You must have some horizontal loads ( wind, seismic , thermal... even for sliding support you must consider friction )

The following doc . for horizontal vessel, still you can see the concept for slipper design

https://edoc.pub/horizontal-vessel-foundation-design-pdf-free.html

Tim was so learned that he could name a
horse in nine languages: so ignorant that he bought a cow to ride on.
(BENJAMIN FRANKLIN )

 

[1503-44]

If protected from wind and no seismic requirements, horizontal load might just be only a friction load of 0.30 x pipe weight.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

On spacing I meant axial spacing of supports.

acceptable span for small bore pipe is a lot lower than 20" pipe.

You often get a smaller intermediate support for the smaller bore line between the bigger ones, so say 8m separation for all pipes and 4m separation for the smaller bore / instrument cable tray.

But its basically bearing load, sliding friction ( make sure it doesn't slide ) and overturning loads.

Hence at worst assume a friction factor of 0.3 and a vertical load of the pipe weight and contents and use that for expansion forces. The 20" will give you 90% of those loads.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[GAURAV G]

Thanks to all, I understand the concepts.
Actually these sleepers are spacing 6m & yes you are correct we need to provide intermediate supports or separation at 3m intervals between 6m sleepers.
So now I know
1. Vertical load
2. Friction load
I will design it for
1. Shear & bending
2. Bearing
3. Sliding
4. Overturning checks

Hope I am aline with you guys.

 

[LittleInch]

Looks good to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Small pipes can often be supported midspan by brackets or hangers tied to the 20".

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."