水毁灾害中埋地管道稳定性研究

Study on stability of buried pipeline in washout disaster

水毁灾害是长输油气埋地管道灾害中造成经济损失最严重、对环境危害最深远的自然灾害之一。为了分析埋地管道在水毁灾害中的稳定性,探讨了埋地管道在水毁灾害中的载荷分布情况;采用特征值屈曲理论,分析了埋地管道在水毁灾害中悬跨和漂浮2种主要形式下,不同管道外径和管道壁厚对埋地管道在水毁灾害中稳定性的影响,计算得到特定条件下埋地管道水毁的极限长度;建立了埋地管道在水毁灾害中的有限元模型。结果表明:管道在水毁灾害悬跨和漂浮情况下极限长度和屈曲位置不同,随着管道壁厚的增加,埋地管道在水毁灾害中的稳定性近似呈缓慢的线性增长;增大管道外径能够有效降低埋地管道在水毁灾害中的位移,并显著提高管道在水毁灾害中的抗屈曲能力。

The washout disaster is one of the natural disasters which cause the most serious economic loss and the most serious harm to the environment for the environmental disasters of long distance oil gas buried pipelines. To analyze the stability of buried pipeline in the washout disaster,the load distribution of the buried pipeline in the washout disaster was discussed. By using the eigenvalue buckling theory,the influence of different pipeline external diameter and wall thickness on the stability of buried pipeline with two main forms of suspended spanning and floating in the washout disaster was analyzed.The limit length of washout for buried pipeline under specified conditions was calculated,and a finite element model of the buried pipeline in the washout disaster was established. The results showed that the limit lengths and the buckling positions of pipeline under the conditions of suspended spanning and floating in the washout disaster were different. The stability of buried pipeline in the washout disaster approximatively presented a slowly linear growth with the increase of wall thickness.Increasing the external diameter could effectively reduce the displacement and significantly improve the resistance to buckling of the buried pipeline in the washout disaster.