管道体积型缺陷剩余强度评价方法误差分析

Error Analysis of Residual Strength Assessment Methods for Pipeline with Volume Defect

研究了5种较为通用的油气管道体积型缺陷剩余强度评价方法,对评价方程计算结果与含缺陷管道的爆破试验结果进行比较,得出了各种评价方程的计算误差,对误差的分布区间进行了分析。结果表明,与Origin B31G方程评价结果相比,Modified B31G方程评价结果的保守性大大降低;许用应力法和PCORRC方程的评价效果较好,API 579-1标准给出的评价方程同样存在评价结果过于保守的问题;对不同级别的管线钢,同一种评价方程的评价效果存在差异。

The five common methods used residual strength assessment for oil and gas pipeline were studied.By comparing the results calculated by strength assessment equations and measured by blasting experiments,the calculation error of these equations were obtained.Then the error distribution interval was analyzed.The results showed that the equation of Modified B31G was less conservative than Origin B31G.Allowable stress method and PCORRC equation had the better evaluation results.The evaluation equation given by API 579-1 standard also had the problem of too-conservative evaluation results.For the different grade pipeline steels,the evaluation effects of the same evaluation equation were different.