滑坡灾害中埋地管道稳定性分析

Stability analysis of buried pipeline in landslide disaster

滑坡灾害导致的管道局部失稳是油气管道面临的严重威胁之一。为了探讨滑坡灾害中工程管道位移、应力随参数的变化规律,研究管道结构稳定性,采用有限元方法,以管道外径、径厚比、滑坡宽度为研究变量,计算并分析了在滑坡灾害中管道位移、应力和稳定性。研究结果表明:增大管道外径可以有效抑制滑坡灾害中管道位移,同时随着管道外径的增加,管道最大位移呈现二次曲线降低,并且径厚比越小管道位移增量越小;滑坡灾害中管道的最大应力发生在滑坡中心和两端位置;以外径为0. 965 m管道为例,屈曲特征值分析结果显示,随着管道径厚比的增大,屈曲特征值呈二次曲线减小;随着管道外径的增加,屈曲特征值呈线性增大,并且屈曲位置发生在滑坡段中间位置,管道所能承受的极限滑坡宽度约为70 m。

The local instability of pipeline caused by the landslide disaster is one of the serious threats to the oil and gas pipelines.In order to investigate the variation laws of displacement and stress with the parameters of engineering pipeline in the landslide disaster,and study the structural stability of pipeline,taking the outer diameter and diameter-thickness ratio of pipeline and the landslide width as the research variables,the displacement,stress and stability of the pipeline in the landslide disaster were calculated and analyzed by using the finite element method.The results showed that increasing the outer diameter of the pipeline could effectively suppress the displacement of pipeline in the landslide disaster.At the same time,with the increase of the outer diameter of pipeline,the maximum displacement of pipeline decreased as a quadratic curve,and the smaller the diameter-thickness ratio,the smaller the displacement increment of pipeline.The maximum stress of pipeline in the landslide disaster occurred at the middle and both ends of the landslide.Taking a pipeline with the outer diameter of 0.965 m as an example,the analysis results of buckling characteristic value showed that the buckling characteristic value presented a quadratic curve decrease with the increase of the diameter-thickness ratio of pipeline.With the increase of the outer diameter of pipeline,the buckling characteristic value increased linearly,the buckling occurred at the middle of the landslide section,and the limit landslide width that the pipeline could bear was about 70m.