管道受横向滑坡作用破坏分析——以中缅管道贵州晴隆段两次爆炸事故为例

Analysis of Pipeline Damage Caused by Lateral Landslides:Taking Two Explosion Accidents in the Qinglong Section of China-Myanmar Pipeline in Guizhou as an Example

穿越山区的管道工程的运行安全会受到滑坡的威胁,滑坡事故造成了大量的人员伤亡和经济损失。以中缅天然气管道贵州晴隆段2017年和2018年两次滑坡断管事故为例,结合地质环境条件和现场事故调查资料,基于有限元实体接触模型,反演两次事故发生过程。分析管道在滑坡作用下的受力与变形特征,以确定事故发生原因。研究结果表明:滑坡作用下管道挠度变形呈现近正态式分布,且管道跨中和滑坡边界处Mises应力较大,易于发生破坏;管道所在斜坡上方的大量积土,致使管道产生较大轴向拉应力,易于在管道管体或环焊缝缺陷处产生脆性拉裂破坏,进而引起燃气泄漏爆炸。因此在管线后期维护过程中应避免受到工程扰动,尤其在管道上方的斜坡体上进行大量堆土,防止对管道的运行安全造成威胁。

The operational safety of pipeline projects crossing mountainous areas is threatened by landslides,which have caused a large number of casualties and economic losses.Taking the two landslide and pipe breakage accidents of the Guizhou Qinglong section of the China-Myanmar natural gas pipeline in 2017 and 2018 as examples,combined with geological environmental conditions and onsite accident investigation data,based on a finite element entity contact model,the process of the two accidents was inverted.The stress and deformation characteristics of pipelines under landslide action was analyzed to determine the cause of the accident.The results show that the deflection deformation of the pipeline presents nearly normal distribution under the action of landslide,and the stress at the middle and boundary of the pipeline is relatively the largest and is easy to be destroyed.The accumulation of soil above the slope where the pipeline is located causes the pipeline to produce large axial tensile stress,which is easy to produce brittle crack damage at the pipe body or girth weld defects,and then cause gas leakage and explosion.Therefore,the pipeline should be avoided engineering disturbance during the later maintenance of the pipeline,especially a large amount of soil piled above the slope.It would prevent threats to the operation safety of the pipeline.