steel pipes in soft ground
steel pipes in soft ground
(OP)
Im relatively new to the water world. For a pressurised steel water supply pipeline laid in relatively soft ground, what is the normal approach to minimize differential settlement between the pipes and chambers and anchor/thrust blocks?
Is the option of piling the chambers to a floating length (rather than to set) viable?
I read that rocker pieces are used to allow for settlement but being a pressurised main, it seems to me that the rocker pieces will need to be restrained, will this end up limiting the amount of deflection available?
Is the option of piling the chambers to a floating length (rather than to set) viable?
I read that rocker pieces are used to allow for settlement but being a pressurised main, it seems to me that the rocker pieces will need to be restrained, will this end up limiting the amount of deflection available?
RE: steel pipes in soft ground
What is the size of the pipe?
"relatively soft ground" is not an engineering term.
What type of "chamber" are you talking about?
Are you talking about restrained piping with flexible joints?
Use of thrust blocks is old fashioned.
RE: steel pipes in soft ground
Will Rocker pieces be useful in this? E.g short length of pipe with mechanical couplings on both ends to allow for deflection.
RE: steel pipes in soft ground
The aim is to avoid differential settlement by providing firm ground under the pipe.
Peat is a nightmare of a material to work with and for large diameter, relatively thin pipes can be catastrophic. The only sure way to deal with it is dig out the peat down to bedrock / firm layer and backfill with something solid to create a subterranean road on which to lay your pipe.
Otherwise as you note, some sort of flexibility is required to avoid the issue. Flexible couplings are also difficult tog et right, especially at that sort of size and can limit the pipe design pressure.
I have seen gently curved hard backfill away from a fixed point like a valve chamber or connection and then rely on the ground level in general to support the pipe, but prevents a hard spot.
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RE: steel pipes in soft ground
Im currently looking for articles and case studies for design and construction of steel mains in poor ground conditions. Any suggestions will be appreciated!
RE: steel pipes in soft ground
Why are the cambers piled - why not let them move with the pipe ?
RE: steel pipes in soft ground
RE: steel pipes in soft ground
RE: steel pipes in soft ground
RE: steel pipes in soft ground
I have seen underground supports used, but I'm not a fan of those - if the ground under the pipe settles then the pipe ends up holding the ground up which is a lot of weight concentrated in a hard spot.
In general you try and avoid ground like this so there aren't too many examples, especially where you connect buried pipes to hard stuff, but try looking for muskeg pipe construction which is what they seem to call peat in Canada.
digging it out back to solid ground is still the best long term solution
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.