EXPERIMENTAL AND NUMERICAL STUDY ON AXIAL MECHANICAL PROPERTIES OF PIPELINE UNDER PSEUDO-STATIC LOADING

A series of pseudo-static tensile tests were performed on the push-on joints of ductile iron water pipeline specimens to investigate the axial mechanical properties and failure mechanism of the joints. A new finite element model for the push-on joint was also developed in this study. The pseudo-static tests were carried out on the push-on joints of ductile iron pipeline specimens using both monotonic and cyclic loading to investigate the behavior of the joints under repetitive axial loading, such as seismic loads during an earthquake event. It was found that the effects of the different loading protocols and internal water pressure on the axial response and failure modes of the push-on joint were negligible in this experimental study. The tension displacement limit of the joints reached 60 cm. Finally, a new finite element joint model was developed in OpenSees to simulate the axial behavior of the push-on joint observed during the experiments. The proposed numerical joint model can well capture the characteristic axial response of the joint, such as axial stiffness degradation and energy dissipation. Both the experimental and numerical results provide a support in assessing the performance of the push-on joints of water pipelines subjected to complex axial loading.