关键词: 寒区输油管道, 应变设计准则, 冻胀变形量, 极限状态

Abstract: Complex geological environment along the pipeline in cold regions, such as landslides, the frost heave and thawing settlement, probably makes the pipe a large differential deformation leading to its failure. Large differential deformation caused by the stress and strain behavior directly affects the safety of pipeline during operation, and even damages the pipe. Based on the actual stress/strain conditions of oil pipeline in cold regions, we fully considered the frost heave, oil pressure and thermal stress effects on the pipeline, and analyzed its factors and the axial tensile strain distribution with different lengths, thicknesses, oil pressures. According to axial strain design criterion, the limit conditions of the oil pipelines were established. The maximum limit of the frost heave deformation for pipelines was obtained. Results show that the stress-based design criteria is conservative, and the strain-based design can use the deformation of the pipes more efficiently. This article can provide references for the reasonable design, safety evaluation and integrity management of pipeline.

Key words: oil pipeline in cold regions, strain-based design criteria, frost heave, limit state