Pipeline systems are vital but are often damaged severely under earthquake actions. Because a well-designed bellow joint has a high deformation capacity and low stiffness, it can be used as a connector to protect pipes. In this work, a pipe with a bellow joint was buried in a steel box filled with soil. The pipe was fixed at one end, and an axial cyclic displacement was applied at the other end. Strain, axial force, and deformation along the pipe were collected. Results indicate that all the deformation was concentrated at the joint, while the pipe experienced no damage and was fully functional after the test. A finite-element (FE) model respectively with and without a bellow joint was then developed to comparatively study the effectiveness of the joint. The results obtained from both experiments and FE analysis show that the bellow joint can efficiently reduce the axial force and increase the deformation capacity.

In an accompanying paper, pipes that were connected by a bellow joint were examined under cyclic axial loading. The results show that the bellow connection can significantly reduce the axial force and increase the deformation capability of the pipe-joint system. In this work, the pipes connected with a bellow joint were further investigated under cyclic shear loads. The pipe was buried in two steel boxes filled with soil. One box was fixed to the strong floor, and the adjacent box can move in a transverse direction. The ends of the pipe were each fixed to the far surface of the boxes. A transverse cyclic shear displacement was applied to the movable box. Axial elongation along the pipe, shear load, and deformation were recorded by a data logger. The results indicated that most of the deformation of the pipe-joint system was contributed by the joint, so less damage to the pipes was observed. A finite-element (FE) model with and without a bellow joint was then developed to evaluate the effectiveness of the joint. The results of FE analysis and the experiments showed that the pipe with a bellow joint experienced much smaller axial force and had greater deformability compared to the pipe without a bellow joint.