Study on the motion patterns of shallow-embedded pipelines in sand

Abstract

Pipe-soil interactions are a crucial consideration in the realization of shallow-embedded pipelines’ in situ stability, and the choice of pipe-soil interaction model is correlated with the distinction between “light” and “heavy” pipe motion patterns. Based on the difference in the motion pattern of a shallow-embedded pipeline in sandy soil after a breakout, a numerical model of pipe-soil interaction is constructed. The influencing factors of different motion patterns are studied, while taking into account the shear expansion or shrinkage characteristics of sand. Accordingly, a method of discriminating pipeline motion patterns is proposed. The results show that the motion pattern of a shallow-embedded pipeline in sandy soil depends on the relative weight of the pipe and soil bearing capacity, that the smaller the embedment, the easier the “heavy pipe” motion pattern appears, and that the critical pipe weight required for “heavy pipe” motion increases with initial sand density and pipeline embedment depth.