Thrust Restraint Collars

[s0eebuch]

Anyone know of a good resource for designing thrust restraint collars?

The application is a 16-inch diameter ducitle iron watermain along a busy roadway in Virginia.

I'm looking at options for thrust restraint (thrust collars, thrust blocks, restrained joints, combinations of these) and was curious about thrust collars. I came across a detail for them in an older set of plans.

Are thrust restraint collars no longer utilized?

Any "seasoned" help would be most appreciated!

 

[rconner]

Integrally-cast, welded-on, or otherwise affixed “thrust collars” embedded in variously constructed transverse concrete walls are a well-known and well-proven means of handling e.g. even very large pressure-induced thrusts in buried pressure pipelines. While transverse trenches for such walls can be rather quickly dug in suitable soils for pouring of such walls (e.g. see page 9-29 at

http://www.acipco.com/adip/products/Sect9.pdf

), probably the most common applications of collars are for “wall pipes” or “wall sleeves” for various embedments in reinforced concrete structure walls (pump station or treatment plant buildings, or valve or meter vaults etc.) e.g. such piping structures as also pictured in page 7-6 etc. at

http://www.acipco.com/adip/products/Sect7.pdf

.
In addition to handling thrusts (of subsequent pipe assembly and pressure etc.) wall collars also provide (and particularly with steel or iron constructions that normally knit quite well with poured concrete) a more tortuous path for any potential water leakage along the outside of the pipe, for enhanced “waterstop” function through the wall as well/and where this is desired e.g. in tank or vault walls etc.
Of course in all applications the wall itself must be constructed with adequate shear and bending strength, that sometimes for high thrust applications requires substantial wall thickness and/or increased steel reinforcement of the wall penetration (designed by the structural Engineer), and independent thrust walls or vaults must of course be provided with a face/size that mobilizes adequate bearing area against the soil mass. sometimes only area against "undisturbed soil" is what is considered for such face sizing.
[I can see one potential drawback as to the use of thrust collars/ walls (perhaps along some busy roadways?) is that this can obviously complicate the future installation of parallel utilities in the same corridor or R-O-W. If such future contructions are known or anticipated, I guess it might be possible however to go ahead and embed suitable sleeves or casings in the wall when it is constructed, and/or make other necessary provisions and/or precautions for future work in the area etc.]

 

[dicksewerrat]

Use "MegaLUg" retainers. Call the DIP Vendor. you will need to use some mech. joint pipe.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com