The Mechanical Behavior And Reliability Analysis Model Of Pipeline Corrosion Defects Under The Action Of Flood Disaster

Oil and gas pipelines in our country is facing the double threat of various geological disasters and human activities,oil and gas pipeline safety is directly related to theChinese energy.Pipeline safety issues are key issues to be solved in our country.Through the literature and survey of pipeline accidents in recent years,found water damage is the one of the key factors of geological disasters in China in the pipeline safety.Through access to a variety of information,combined with the practical problems encountered in pipeline engineering.This paper first analyzes the oil and gas pipeline current safety,economy,technology,etc.According to findings of the southwest area of China oil and gas pipeline and existing information,and using the common methods to classify our pipeline watering of our country,and obtained waterlogging recognition classification through to various classification rules.Combination of pipeline waterlogging classification results,this paper further explains the causes of waterlogging the pipe and pipe the effect of waterlogging form.In addition,based on the Lanzhou-Chengdu-Chongqing products pipeline de Yang Shiting River washout resulting in hanging pipe 380 meters of the actual case,access to pipe data and the parameters of the soil,waterlogging reaction conditions,Using the large finite element software Abaqus,pipeline and soil function model is set up.In this paper.First of all,verify the limit length of dangling pipes are suspended in the case of up to 436 meters.then,Establish diameter-thick ratio of 100:a numerical analysis model of suspended pipeline,And obtained different diameter of the pipe length of the limit of the impendingunder the condition of diameter-thick ratio of 100:1.At the end of this paper,the limit length of the pipeline with corrosion defects is studied,and the limit state equation of the length of the pipeline is established.The concrete steps are as follows:(1)Collect pipeline corrosion data,And determine the shape of the corroded pits in the pipeline.(2)The corrosion pits located at the pipe end and the middle of the pipeline are established.And the influence of the depth,width and length of the corrosion pit on the length of the pipeline is considered.Then draw the influence of the depth of the limit length of the curve,the width of the influence of the length of the curve,the length of the influence of the length of the curve.And the impact of the pit corrosion of the maximum displacement curve.(3)combined the influence of corrosion pits on the length of the pipeline with the influence of the factors,the limit state equation of the length of the pipeline is established,and the common methods to calculate the failure probability and reliability are introduced.The conclusions of this paper(1)According to the disaster reason,medium power and location,pipeline crossing terrain,damage mechanism and damage the terrain,the damaged pipeline scale,the flood classification table is established.According to the result of division,effects of geological condition,precipitation,artificial activities on flood disaster of the pipeline are analied.(2)When the diameter thickness ratio is 100:1 and the diameter is greater than 530 mm,the limit length of the pipe remains unchanged with the increase of pipe diameter.(3)The location of corrosion pits has a great influence on the critical length of the pipeline,and the corrosion pit has the most influence on the pipe end.(4)The limit length of the pipeline with corrosion defects decreases with the increase of corrosion depth.(5)the limit length of the pipeline with corrosion defects decreases with the corrosion width.(6)the corrosion pit length has little effect on the limit length of pipeline.(7)the length,depth and width of corrosion defects have little effect on the maximum displacement of the pipeline.(8)the limit state equation of corroded pipeline is established...