PIPELINES AND LATERALLY LOADED PILES IN ELASTOPLASTIC MEDIUM

The uplift behavior of a shallow pipeline embedded in an elastoplastic medium is examined. An analytical solution for a beam on elastoplastic foundation is developed and a characteristic nondimensional load-displacement and stress-displacement relationship are presented. An approximate three-dimensional (3D) solution is proposed that accounts for embedment and breakaway condition behind the pipeline making use of the load-displacement curves developed for rigid anchors by Rowe and Davis in 1982. A comparison of these results with those obtained by 3D finite-element analysis indicates that the simplified solution of a beam on elastoplastic foundation is a practical alternative for analyzing the uplift behavior of shallow pipelines. The approximate solution is also used to compare the behavior of a laterally loaded pile for which no separation or separation between the surrounding soil and the back of the pile is permitted as the load is monotonically increased. The results are presented in the form of nondimensional charts that permit hand calculations and rapid verification of structural design of the pipeline and piles.