中俄原油管线冻土融沉对输油管道应变的影响研究

Study on influence of thawing permafrost in the China-Russian crude oil pipeline on strain of oil pipeline

中俄原油管线所穿越的欧亚大陆冻土区稳定性较差,差异性地质构造普遍存在,管道正常运行极易引发融沉灾害,造成管沟积水,影响管道安全运行。利用Abaqus软件建立管—土三维有限元模型,基于应变设计准则考虑管线钢的材料非线性特性,研究分析管道穿越冻土融化区域时管道的应变变化规律及融化段长度、融化深度、管道内压3种参数对管道应变的影响。研究结果表明,管道处于冻融区域时会产生3个应变集中区,最大等效应变值出现在管道顶部即融化段中部。融化段长度对管道应变影响最大,内压次之,融化深度影响最小。研究结果可为今后冻土地区埋地管道工程的运行维护提供理论参考,以保证管道在服役期内安全运行。

The permafrost regions of the Eurasian continent that the China-Russian crude oil pipeline traverses have poor stability,and differential geological structures are common.The normal operation of pipeline can easily cause thawing and subsidence disasters,causing water accumulation in pipe trench,which affects safe operation of pipeline.In this paper,Abaqus software is used to establish a pipe-soil three-dimensional finite element model.Based on strain design criteria,the nonlinear characteristics of pipeline steel are considered,and strain change law of pipeline when pipeline passes through frozen soil melting area is studied and analyzed.The influence of three parameters of pressure on pipeline strain.The results show that when pipeline is in freezing and thawing zone,three strain concentration zones will be generated,and the maximum equivalent strain value appears at top of pipeline,that is,in middle of melting section.The length of melting section has greatest influence on strain of pipeline,followed by internal pressure,and depth of melting has the least influence.The research results can provide a theoretical reference for future operation and maintenance of buried pipeline projects in frozen soil areas to ensure safe operation of pipeline during service period.