GRP Pipe in Reactive Clay

[stanier]

Hi,

I am researching the behaviour of GRP pipe buried in reactive clays. I am looking for articles or books that cover the analysis of the soil/pipe/embedment structure.
AWWA standards cover the design of GRP in trenches subject to external loading from soil, vehicles, aircraft etc. However reactive clays are going to provide a pressure from below the haunches resisted by the trench and overburden.

I am interested in the stress, strain, combined loading deflection and buckling criteria.

I have found research on PE pipes in such soil but so far none on GRP.

Your experiences in such installations would also be welcomed.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[stanier]

This message transferred to the Pipelines, Piping and Fluid Mechanics Forum.

 

[bimr]

Data are generally lacking concerning the forces that may be imposed on buried piping in clay soils. The reason for this is that design practices generally do not allow such soils to be placed around the pipe. For sanitary sewers for example, design practice generally requires such soils to be removed for certain depths below the pipe if moisture content is variable at such depths.

Here is an example:

If the base soil is unstable (for example, peat, quicksand, muck, landfill, or very soft or highly expansive clay), the site should be overexcavated in width and depth and a firm, compacted base of 1/2-in. to 3/4-in. (13- to 19-mm) crushed rock should be set before the sand or pea gravel bedding is placed. In extreme conditions, a concrete layer may be needed to stabilize the bottom of the excavation. If you have any doubt about the soil’s ability to
support the tank, consult a local civil or structural engineer.

http://www.norgam.com/pdf/costa03.pdf

You might consider posting this query in the geotechnical forum or consult with a geotechnical engineer.