Mechanical Properties of Bellows Joint-Connected Buried Pipelines Subjected to Normal Fault: Parametric Analysis

Buried pipelines that cross normal faults are at risk of damage because of insufficient deformation capacity. Bellows joints have been proven to have the potential to significantly increase the deformation capacity of the pipelines; however, the geometric parameters of bellows joints are crucial in determining the performance of buried pipelines under normal fault. In this study, mechanical tests of a buried steel pipeline with a two-convolution bellows joint were conducted first. A finite element model (FEM) was developed in ABAQUS software and verified using the test results. The impacts of convolution number, radius, and spacing of the bellows joints in the buried steel pipelines were then analyzed based on the validated FEM. The numerical results indicate that the bellows joint can effectively withstand ground deformation caused by normal faults. Increasing the number of convolutions, employing a larger convolution radius, and maintaining a certain convolution spacing can enhance the deformation and energy absorption capacity of bellows joints.