Seismic damage to buried pipelines in previous earthquakes has generally resulted from insufficient deformation capacity of the joints during a permanent ground deformation such as faulting. Previous research has demonstrated that a well-designed bellows joint exhibits high deformation capacity and low stiffness, providing effective connectors for pipeline protection. However, the influence of the geometric characteristics of bellows on the performance of buried pipelines subjected to faulting is not clarified. In this work, a buried steel pipeline connected with a 2-convolution bellows joint was first tested under cyclic loading, and the test results were utilized to validate a finite-element model developed in ABAQUS. Subsequently, parametric studies of the bellows joint in buried steel pipelines subjected to reverse fault displacement were conducted using the verified finite-element model. During the parametric analysis, the number of convolutions, radius, and spacing of bellows joints were considered and discussed in detail. The results indicate that the bellows joint can efficiently reduce the axial force and enhance the deformation capacity of the buried pipelines. Increasing the number of convolutions is the most effective way to improve the deformation capacity, and enlarging the convolution radius and spacing can enhance the energy absorption capacity of the bellows joint.
Li et al. (Wed,) studied this question.