Research on local buckling failure range of X80 buried steel pipeline under oblique-reverse fault

Permanent ground deformation induced by the earthquake will cause serious damage to long-distance buried oil and gas pipelines, resulting in buckling failure or even cracking damage to pipelines. Based on the ABAQUS program, a 3-D numerical model of X80 buried steel pipeline crossing oblique-reverse fault was established, and the failure characteristics and failure range of local buckling of buried pipeline were systematically analyzed. According to the engineering parameters of the Second West-East Gas Pipeline Project (China), the influence of fault dip angle, displacement, diameter-thickness ratio, burial depth, and internal pressure on the local buckling failure range of the pipeline was discussed in detail. Subsequently, regression analysis was carried out on the numerical results of 1800 sets of the finite element cases, and a semi-empirical prediction equation ("Risk Segment" regression formula) of the local buckling failure range of X80 steel pipeline subjected to oblique -reverse fault displacement was derived. The accuracy and applicability of the formula were verified by the numerical results of 120 practical examples. The results show that the "Risk Segment" regression formula has higher accuracy and is less time-consuming, which is suitable for failure range prediction and local safety design of X80 buried steel pipeline under oblique-reverse fault.