Thrust Block
Thrust Block
(OP)
Anyone have any experience with thrust blocks, codes, tips, advice?
I've been asked to design one and honestly don't know where to start besides the location and size of the pipe and where the pad should be placed.
Thanks for any help.
I've been asked to design one and honestly don't know where to start besides the location and size of the pipe and where the pad should be placed.
Thanks for any help.






RE: Thrust Block
From what I have seen, they were just giant blocks of concrete poured around pipes where the pipe changed direction.
RE: Thrust Block
You could specify retainer glands and save yourself the trouble..
Or for a block I'd just specify half a yard of concrete over and on the outside of the fitting, and make sure they put poly over it.
RE: Thrust Block
As for design, use passive pressure of soil to resist but here is a tip. Since the soil that you are going to using for passive will be most likely disturbed as you are going to pouring the block, use half the recommended value as your passive pressure.
You may also end up with a joint where you have you have uplift, in which case just use the weight of the conc to resist.
RE: Thrust Block
RE: Thrust Block
http://www.dipra.org/publications/design.cfm
It is not just a matter of dumping in an arbitrary amount of concrete. Thrust blocks should be designed to resist the forces involved. For that, you will need a soil investigation to provide safe bearing values.
BA
RE: Thrust Block
"It is not just a matter of dumping in an arbitrary amount of concrete"
Oh, IF ONLY structural engineering were that. Well, wait a minute, we would not be needed then....
RE: Thrust Block
Many of the ones I have seen were not simply big blocks of concrete. A lot of them included rock anchors or similar due to uplift concerns or desire to reduce the amount of concrete. Consideration should be given to adding rubber gaskets at each end of the block to reduce prying forces depending on the situation.
RE: Thrust Block
-This is inside a new pumping station (not in service yet)
-The slab has already been poured
-The resistance is for a 30" discharge pipe
-The location is at a 90 degree turn where the pipe exits the building.
I will continue to research per everyones advice.
Thanks!
RE: Thrust Block
There have been a few threads on this topic in the civils forum, I suggest you look there.