纵向滑坡作用对管道应力应变的影响研究

Study on the Effect of Longitudinal Landslide on the Stress and Strain of Pipeline

摘要: 滑坡地质灾害易造成油气长输管道变形失效，严重威胁管道的安全运营。为明确纵向滑坡作用对管道应力应变的影响，通过实际地质勘测建立了管道分析模型，进行了纵向滑坡作用下管道应力应变的数值模拟，利用解析法进行检验，确定了不同土壤剪切角时管道临界应力下纵向滑坡的长度与位移。分析发现：管道轴向受压时两端均会出现一个褶皱，应力集中在两端；数值模拟与解析法计算出的垂直管道临界应力分别为481.7 MPa、446 MPa，误差仅7.4%，能够作为管段应力预警阈值的参考；针对实际长输管道选取的5个危险点，获得不同土壤剪切角下纵向滑坡长度和位移，与分析结果一致，可作为纵向滑坡预警阈值的科学参考。研究结果对纵向滑坡地质特征数据监测时滑坡长度与位移、管道应力阈值的设定具有重要意义。

Abstract: Long-distance oil and gas pipelines are frequently deformed and break as a result of landslide geological disasters, gravely jeopardizing their ability to operate safely. An analytical model of the pipeline was developed by actual geological survey in order to better understand the impact of longitudinal landslides on the stress-strain of the pipeline. Numerical simulation of the pipeline’s stress-strain under the influence of longitudinal landslides was then performed, and the length and displacement of the longitudinal landslide under the critical stress of the pipeline at various soil shear angles were calculated using the analytical method. The analysis revealed that: when the pipe is axially stressed, a fold will form at both ends because the stress is concentrated at both ends; the critical stresses of the vertical pipe calculated by numerical simulation and analytical method are 481.7 MPa and 446 MPa, respectively, with an error of only 7.4%, which can be used as a benchmark for the stress warning threshold of the pipe section; Five risk points chosen for the actual long-distance pipeline were measured for the length and displacement of longitudinal landslides under various soil shear angles. These measurements are consistent with the analysis results and can be used as a scientific benchmark for the warning threshold of longitudinal landslides. The study’s findings are crucial for determining the duration and displacement of landslides as well as pipeline stress thresholds during the ongoing monitoring of longitudinal landslide geological feature data.