Pipeline Supported on a Nonuniform Winkler Soil Model

After a buried bell-and-spigot pipeline was installed at a site, an interior survey showed that some of the pipe sections were as much as $450\mathrm{mm}$ above the intended grade. One proposed explanation for this phenomenon was that the pipe sections were acting like teeter-totters, with one end settling and the other heaving, due to the variable foundation conditions. Later, when a similar pipeline was planned for the same vicinity, analyses were made utilizing a nonuniform Winkler soil model with randomized spring constants. The analyses showed that the calculated settlements were negligibly small; and there was no predicted teeter-totter behavior. Subsequent measurements confirmed the analyses.