Analyses of the mechanical characteristics of long-distance crude oil pipeline support assembly on “L”-type pipeline

Abstract

Trenched crude oil pipelines rely on anchor blocks and pipe supports for stability, however mechanical interaction remains unclear, limiting design safety. This study employs fluid-solid-thermal coupling methods to establish a three-dimensional finite element calculation model of an “L”-type crude oil pipeline based on an equivalent model of the end-side displacement of the anchor block and pipe section. The mechanical response patterns of anchor blocks and pipe supports to the isolated action of “L"-type pipes were investigated separately. After evaluating the optimal design position of pipe supports to balance internal forces within the pipe, we further investigated the synergistic optimisation mechanism of anchor blocks and pipe supports on the mechanical characteristics of the pipe. Results indicate that the anchor block provides limited protection to the structural safety of pipeline. Under 300 mm end-side displacement imposed by anchor block, the maximum deformation of elbow decreases by 2.31 mm. However, increasing the end-side displacement from 500 mm to 600 mm reduces the maximum deformation by only 0.05 %. A symmetrical distribution of pipe supports delivers the optimal solution, lowering the maximum stress of the pipeline to 78.049 MPa, the 25.55 % reduction. Additionally, the combined use of anchor blocks and pipe supports demonstrates a synergistic optimisation effect on pipeline safety, reducing elbow deformation by approximately 85.14 % (to 33.121 mm). These findings provide a theoretical basis for optimising the working conditions of pipeline support assemblies in long-distance crude oil pipeline networks.