The pipeline joint is a key and weak segment affecting the daily operation safety of the mu- nicipal water supply network. However， most of the current investigations were devoted to the me- chanical performance of pipeline joints under seismic and axial loading， while there were few studies on the flexural mechanical behaviors of ductile iron water supply pipeline joints under vertical loading， resulting in a lack of comprehensive evaluation on this type of pipeline joints. In this study， the ductile iron water supply pipeline joint is taken as the main research object to study its damage behavior under vertical loading by experiment and numerical simulation. The results indicate that：(1) the contact fail- ure of the rubber sealing ring in joint is the main cause of the pipeline leakage；(2) the relative rotation angle of the pipeline joint and the vertical load have a good positive correlation；(3) The relative rota-tion angle when the pipeline exhibits water leakage is around 12°. Therefore， there is a need to per- form a refined design for water supply pipeline joint and rubber sealing ring in order to avoid the failure of pipeline joint under different loading circumstances such as contact sliding， rotation and drawing， so as to increase the maximum allowable relative angle of the pipeline joint， and to develop the excellent compression and deformation ability of the rubber sealing ring.
