腐蚀管线失效概率的评定方法

基于结构可靠性的一般理论,建立了腐蚀缺陷管线失效的极限状态函数,并以规则化的随机变量形式表示.采用雷菲法求解了失效概率,提出了管线全线的失效概率分析方法,即沿管线全长以1km管线为失效概率的分析单元进行计算,这样能合理考虑管线沿线腐蚀状况的差异.对一条经过检测的输油管线的腐蚀缺陷数据、管道运行参数和管材性能参数进行了统计分析,运用新提出的概率数学模型计算了管道全线的失效概率,并与推荐的目标失效概率进行了比较,从而提出了对管线重点维修和监测的区段.本方法是在对油气输送管线的腐蚀程度检测之后再进行安全评定的一个行之有效的方法.

Assessment method for failure probability of corroded pipeline

Based on the general theory of structure reliability,a limit-state function for assessment of failure pipeline was established and expressed as the normalized random variables.The R-F method was employed to compute the failure probability of pipeline.A mathematical model for analysis of failure probability along the total length of a pipeline was presented,in view of the difference of corrosion over the pipeline.It means that the failure probability per kilometer of a pipeline is taken as an analytical element for computation. The statistic analyses on the corrosion-inspected data,operation parameters and material performance of an inspected oil pipeline were made.The failure probability of the pipeline was computed in accordance with the new mathematical model.The computed results of failure probabilities were compared with the suggested target failure probability to determine the pipeline sections for further maintenance and inspection.The method is feasible to safety assessment of pipeline especially after corrosion of a pipeline has been detected.