Failure analysis of buried pipelines under the action of oblique slip faults

Oil and gas are often transported by long-distance buried pipelines. When the pipeline is subjected to faulting, the pipeline is highly susceptible to failure under axial loading. However, there is a lack of understanding of the effect of inertial loads on pipeline failure in the analysis of influencing factors under the action of faults. Most of the current studies mainly use static or quasi-static methods to analyze the performance of buried pipelines, often ignoring inertial loads, which may also have an impact on pipeline failure. Therefore, this paper proposes a threedimensional numerical model considering the dynamic response, and adopts ABAQUS explicit dynamics module to analyze the failure of pipelines under the action of sudden oblique slip faults. Firstly, the deformation features and strain development of the pipeline under the action of oblique slip faults were obtained using response analyses, and three key parameters indicating pipeline failure (local buckling, ovalization and the range of failure) were discussed. Then, the influence of fault velocity, internal pipeline pressure and pipeline wall thickness on pipeline failure were discussed. The results show that with the increase of the failure velocity, the higher the inertia, the smaller the strain and ovalization of the pipeline, the local buckling and ovalization failure are reduced, and the failure fault displacement of the pipeline will increase while the effect on the failure range of the pipeline is small. Therefore, designers and pipeline operators should consider the effects of inertia when analyzing the failure of buried pipelines under fault action.