Stresses and deformations in a buried oil pipeline subject to differential frost heave in permafrost regions

Differential frost heave of the buried oil pipelines in permafrost regions can have an adverse effect on the mechanical status of the pipeline, and seriously endanger the pipeline security. In order to reduce the damage to the pipeline during its designed lifetime, it is necessary to analyze the mechanical behavior of oil pipelines taking into consideration the differential frost heave in the design of the pipelines in permafrost regions. In this paper, an elastico-plastic finite element model for the mechanical behaviors of the pipeline-soil system was established. In order to simplify computations, the effects of the temperature and moisture fields on the problem were considered by applying the computed temperature zones of soils surrounding the pipeline from the thermal analysis, and actual frost heaving ratio of the soils was applied to the mechanical model to calculate the stresses and deformations of the pipeline in permafrost regions. These analyses may provide some useful insights into the possible mechanical states of the pipeline-soil system for the design, construction and operation of the buried oil pipelines in permafrost regions.