滑坡作用下管道变形破坏机理的离心模型试验

    CENTRIFUGAL MODEL TEST ON DEFORMATION AND FAILURE MECHANISM OF PIPELINE UNDER LANDSLIDE

    • 摘要: 滑坡是导致山区油气管道变形破坏失效的主要因素之一,且具有危害大、影响范围广的特点。本文开展了滑坡作用下管道变形破坏的离心机模型试验,获取了土压、管道应变和位移数据的实时变化曲线,得到以下研究结果:(1)管道横穿滑坡时为整体弯曲-局部屈曲、两端张拉变形的破坏模式;纵穿滑坡时为整体弯曲-后缘拉张、坡脚压缩、剪出口附近屈曲变形破坏模式。(2)揭示了滑坡与管道相互作用机理,管道和土体在滑坡变形破坏过程中由于材料特性不同,将会有协调变形和非协调变形阶段。(3)分析了在滑坡作用下,不同敷设方式的管道失效破坏模式,最终得出在坡体滑塌之前,管道已破坏失效,但在管道纵穿滑坡体时,滑坡对管道变形的影响滞后且影较小,建议监测预警应以管道应变等作为监测预警指标。研究结果可为油气管道敷设、工程防护设计及监测预警提供技术支撑。

       

      Abstract: Landslide is one of the main factors leading to the failure of pipelines in mountainous areas, with the characteristics of great harm and wide influence. In this paper, we carried out a centrifuge model test of pipeline deformation and failure under landslides and obtained real-time variation curves of soil pressure, pipeline strain, and displacement data. The results are as follows:(1)When the pipeline transversely passes the landslide, the failure mode is overall bending-local buckling and tension deformation at both ends; when the pipeline longitudinally passes the landslide, the failure mode is overall bending-trailing edge tension, slope toe compression, and buckling deformation near the shear outlet. (2)We reveal the interaction mechanism between landslides and pipelines. Due to the different material properties, the pipeline and soil will have stages of coordinated and uncoordinated deformation. (3)Through analyzing pipeline failure models of different pipeline laying ways under the action of landslides. Finally, we concluded that the pipeline had failed before the landslide happened. But when the pipeline longitudinally passes the landslide, the influence of the landslide on pipeline deformation is more hysteretic and smaller than the transverse pipeline. It is suggested that pipeline strain should be used as an indicator for monitoring and early warning. The research results can provide technical support for oil and gas pipeline laying, engineering protection design, monitoring, and early warning.

       

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