基于子集模拟的埋地管道失效概率评估

Failure probability assessment of buried pipeline based on subset simulation

对失效概率的评估是管道系统风险评价的核心内容,针对目前对埋地管道失效概率问题研究的不足,采用子集模拟方法(SS)建立埋地管道失效概率的定量评估模型以及参数敏感度模型,并对随机变量进行敏感分析。研究结果表明:子集模拟能利用少量样本定量计算出管道失效概率,有效弥补了管道结构可靠性模型中的不足;在管道运行中期,工作压力、腐蚀速率、管道壁厚和屈服强度是对管道失效概率影响较大的4个因素,而腐蚀因素在管道运行后期成为对系统失效概率影响最大的因素。

The evaluation of failure probability has always been the core content of risk assessment on pipeline system. Aiming at the shortcomings of current research on failure probability of buried pipeline,a quantitative evaluation model and parameter sensitivity model on failure probability of buried pipeline were established by using the subset simulation method（SS）. The results showed that the subset simulation can quantitatively calculate the failure probability of pipeline by using a small number of samples,which can make up the deficiencies in the pipeline structure reliability model. In the middle period of pipeline operation,the working pressure,corrosion rate,pipeline wall thickness and yield strength are the four factors with larger influence on the failure probability of pipeline. The corrosion factors have the greatest influence on the system failure probability in the later period of pipeline operation.