The nonlinear mechanical behaviour of pipeline joints influences the seismic response of water supply pipelines. This study presents an experimental investigation of the tensile behaviour of push-on joints of ductile iron (DI) pipelines, subjected to axial tensile forces and internal water pressure. The axial performance and damage states of joints are determined for push-on joints with different diameters. A statistical analysis is then conducted to determine the correlation between tensile strength and joint opening. An empirical equation for estimating the tensile strength of pipeline joints is proposed, along with a normalized failure criterion for joint opening considering water leakage. Moreover, a numerical model for buried pipelines considering nonlinear soil-pipe interaction is developed. Incremental dynamic analysis (IDA) is performed on DI pipelines with explicit consideration of the uncertainty of joint mechanical properties. Seismic fragility curves are developed based on the IDA results. The effect of mechanical parameter uncertainty of pipeline joints on seismic risk assessment of segmented pipelines is quantitatively evaluated. The numerical results indicated that the failure probability of the pipeline considering the uncertainty of joint mechanical properties is approximately 1.5 to 2 times larger than that predicted by a deterministic model.

来源平台：TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY