基于长输气管道与斜坡位置关系的管道地质灾害易损性探讨——以中缅天然气输气管道(贵州段)为例

Discussion about Pipeline Vulnerability in the Geological Hazards Based on the Relationship between Long Gas Pipeline and Slope Position—Take the China-Myanmar Natural Gas Pipeline (Guizhou Section) as an Example

地质灾害的发生是导致油气管道事故的原因之一。中缅天然气管道沿线地形错综复杂,地貌类型多样。管道敷设与斜坡的位置关系主要有横向、斜交和同向3种类型,这些特殊位置往往是管道地质灾害的高发区。本文通过对中缅天然气输气管道(贵州段)沿线143处管道地质灾害进行统计,分析了天然气管道(管沟)与斜坡的位置关系对管道地质灾害的控制及管道易损性的影响。本文得出如下结论:1) 管道与斜坡的位置关系不同,管沟对斜坡边界条件的改变存在较大差异性,其中横向管沟对斜坡的改变较为显著,导致斜坡边界的改变较大,常形成高陡边坡,稳定性往往较差,是地质灾害最发育的类型,其次为斜交类管沟,而坡向同向类管沟影响较小;2) 横向管道在灾害发生时最易受损,其次为斜交管道,同向管道易损性最小,管道易损部位为管材或焊接有缺陷处。

The occurrence of geological hazards is one of the causes resulting in oil and gas pipeline acci-dents. The landforms along the route of China-Myanmar natural gas pipeline is complicated and varied. The relationship between pipeline laying and slope position mainly includes three types, which are transverse, oblique and coaxial. These special positions are usually the areas with high incidence of pipeline geological hazards. Based on the statistics of the geological hazards of 143 pipelines along the China-Myanmar natural gas pipeline (Guizhou section), this paper analyzed the effects of the relationship between long gas pipeline (pipe ditch) and slope position on the geological hazards controlling and pipeline vulnerability. In the present article, the conclusions were as follows: 1) There are significant differences in the pipe ditch changing the slope boundary conditions due to different relationship between the pipelines and slopes position. Among them, the transverse pipe ditch changes the slope more significantly, resulting in the alteration of the slope boundary and usually forming a high and steep slope with poor stability, which is the most developed type of geological hazards;the second is the oblique pipe ditch, but the influence of the coaxial pipe ditch is small. 2) Transverse pipeline is the most vulnerable to damage in the event of geological hazards, followed by oblique pipeline, with the least vulnerability in the oblique pipeline, and the most vulnerable part of the pipeline is the defective part of pipe or welding.