Research on interaction coefficient between adjacent defects and application in pipeline failure pressure evaluation

The metal loss caused by corrosion seriously threatens integrity of steel pressured pipelines.In order to accurately and efficiently evaluate the failure pressures of pipelines with adjacent corrosion defects, the influence of the spacing and size of adjacent defects on the internal pressure bearing capacity was quantified by a interaction coefficient, and a new method for evaluating the failure pressure of pipelines with adjacent defects based on the interaction coefficient calculation model was proposed, and the proposed method was applied in a failure pressure evaluation of pressured pipelines.The research results indicate that the interaction between adjacent defects is mainly determined by the distance between defects, the maximum depth and minimum length of adjacent defects.The average prediction error of the evaluation method was 0.28%.Compared with existing methods of evaluating the failure pressure of corroded pipelines, this evaluation method not only simplifies the evaluation steps, but also has higher evaluation accuracy, providing references for integrity management and bearing capacity evaluation of pipelines.