A rule of thumb is that if you can keep maximum deflection of the pipe
within 5 percent of the diameter, then a pipe stiffness of w/40 or more
should be sufficient for buckling, assuming you don't have groundwater, in
which case it should be more. "w" is the maximum applied load in psi. Pipe
stiffness, in this instance, is defined as EI/D^3, where E is the modulus of
elasticity in psi, I is the moment of inertia per lineal inch of pipe wall
in in^4, calculated as (t^3)/12 where "t" is the pipe thickness in inches,
and "D" is the pipe diameter in inches. I got this out of an article in an
ASCE Journal that had reviewed the stability behavior of a number of lab
tests on pipes.
If you have access to back issues of these Journals at an engineering
library in your area, I highly recommend that you look this article up. It
is called "Basics of Flexible Pipe Structural Design" by Prevost and Kienow,
and appeared in the July/August 1994 issue of the ASCE Journal of
Transportation Engineering. It's the best paper on pipeline design
methodology I have come across.
From: raul marino puebla mosquera [mailto:raul_marinop(--nospam--at)yahoo.com.mx]
Sent: Thursday, March 15, 2001 6:29 PM
Subject: ratio D/t in buried steel pipes
I need that somebody helps me in order to know where
finding or as much as will be the relationship maximum
D/ t (diameter/ thickness) for tubing of steel welded
in order to be placed under soil.
In my case the tubing it is of 3500 millimeters of
diameter and 9.5 millimeters of thickness of wall.
this steel pipes will place you rings of
I have requested the manual AWWA M11 but I don't still
thank you advanced by their help.
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