石油工业技术监督

为揭示管径变化对柔性复合管位移特性的影响规律，基于三维有限元数值模拟，构建了包含多层复合结构、管土接触界面及油水两相介质的埋地柔性复合管管土耦合分析模型，在统一埋深与内压工况下，选取40～200 mm的典型管径，系统分析不同周向位置的径向位移分布、截面椭圆化程度及变形敏感区分布特征。结果表明：在相同工况下，管径增大将显著放大柔性复合管的径向位移，管道右侧边界线是对管径变化最敏感的位置，其位移增幅明显高于管道上冠部、左侧边界线与下拱脚；管径越大，截面椭圆化程度越高，管土接触压力分布的不均匀性更加突出，截面非对称变形特征更加明显。研究结果可为埋地柔性复合管的结构选型、埋深设计及现场监测布点提供参考，对提升集输管道服役安全性具有一定的工程意义。

In order to reveal the influence law of pipe diameter change on the displacement characteristics of flexible composite pipe, based on three-dimensional finite element numerical simulation, the pipe-soil coupling analysis model of buried flexible composite pipe including multi-layer composite structure, tube-soil contact interface and oil-water two-phase medium was constructed. Under the conditions of uniform burial depth and internal pressure, typical pipe diameters ranging from 40 to 200 mm were selected. The radial displacement distribution, the degree of section ellipticalization, and the distribution characteristics of the deformation sensitive zone at different circumferential positions were systematically analyzed. The results show that under the same operating conditions, an increase in pipe diameter will significantly amplify the radial displacement of the flexible composite pipe. The right boundary line of the pipeline is the position most sensitive to the change in pipe diameter, and its displacement increase is significantly higher than that of the upper crown, the left boundary line, and the lower arch foot. The larger the pipe diameter, the higher the degree of crosssection ellipticilization, the more prominent the unevenness of the contact pressure distribution between the pipe and the soil, and the more obvious the characteristics of asymmetric deformation of the cross-section are. The research results can provide references for the structural selection, burial depth design and on-site monitoring point layout of buried flexible composite pipes, and have engineering significance for improving the service safety of gathering and transportation pipelines.