腐蚀海底管道剩余强度评估

Assessment of Remaining Strength of Corrosive Subsea Pipeline

海底管道在运行期间会因腐蚀而导致强度降低。为预测腐蚀管道的损伤程度，须对腐蚀管道的剩余强度进行评估。详细阐述了DNV RPF101（2010）规范中腐蚀海底管道剩余强度的评估方法，并通过计算分析，对分项安全系数法和许用应力法的保守性进行了比较。结果表明，腐蚀管道的设备检测精度不为0时，存在一个相对腐蚀深度（d／t）0，两种方法的评估结果相同。当相对腐蚀深度大于（d/t）0，前者的评估结果较为保守，反之，后者的评估结果保守。

Strength of subsea pipe in operation phase will be reduced by corrosion. It is necessary to estimate remaining strength of corrosive pipeline in order to forecast damage level of corrosive pipeline. In this paper the assessment method presented in DNV RP F101 （2010） for corrosive subsea pipeline is elaborated. Through calculation and analysis, the conservation of calibrate safety factor method and that of allowable stress approach is compared. It is shown that there exists a relative defect depth （d/t）o; when inspection accuracy is not 0, the two methods provide the same assessment result at （d/t）0. Calibrate safety factor method will have greater conservation, when relative defect depth is larger than （d/t）o. Otherwise, the allowable stress approach has greater conservation.