Numerical Simulation Study on the Performance of Buried Pipelines under the Action of Faults

The present paper investigates the mechanical behavior of buried steel pipelines crossing an active fault. Permanent ground deformation induced by an earthquake will cause serious damage to buried steel pipelines, resulting in buckling failure or even cracking damage to pipelines. Based on ABAQUS software, version 6.13., the model of an interacting soil–pipeline system is established, accounting for large strains and displacements and nonlinear material behavior, as well as contact and friction at the soil–pipeline interface. Numerical analysis is conducted through the incremental application of fault displacement. Combined with the force and deformation characteristics of buried pipelines, a strain-based design criterion is chosen to study the vertical displacement, axial compressive, and tensile strain of buried pipelines, etc. This paper focuses on the effects of horizontal fault displacement, fault type, and fault angle on the structural response of the pipe. The failure of the pipeline, such as wall wrinkling, local buckling, or rupture is identified. Furthermore, the effects of the pipeline internal pressure and pipe wall thickness are investigated. The results show that, when the pipeline depth is 1.5 m under the action of the fault, the buried pipeline will not be subject to beam buckling damage, and both tensile damage and shell buckling damage will occur. In this case, the critical displacement of the tensile failure is more than three times that of the shell buckling failure, which indicates that shell buckling damage is a greater threat to the pipeline. The pipeline is most susceptible to damage under the action of a strike-slip reverse fault. When the fault angle is equal to 45 degrees, the pipeline is more likely to be damaged, while it is relatively safe at a fault angle with 90 degrees. The results of this investigation can determine the fault displacement during pipeline failure and provide some reference for pipeline design.