The properties of the soil around buried pipelines vary in longitudinal direction

which directly affects the seismic performance and reliability of the pipelines. On the basis of design response spectra

artificial ground motions with different seismic intensities were generated

and a simplified elastic foundation beam model was adopted to analyze the dynamic response of pipeline joints under the seismic wave passage effect. Considering the reduction in the tensile strength of ductile iron water pipeline joints caused by factors such as installation difference and pipeline aging

the effects of four uncertain parameters (soil weight

internal friction angle

cohesion

and yield displacement of soil spring) on the seismic response of buried pipelines were investigated

and the uncertainties of soil parameters under different seismic intensities and weak joint ratios were analyzed. Results show that compared with the calculation results of the model with parameter certainties

and the influences of the four uncertain parameters on the peak dynamic response of joints from large to small were cohesion

internal friction angle

soil weight

and soil spring yield displacement. The model containing four uncertain parameters had the greatest influence on the results

and the variation coefficient of peak joint opening was up to 9.54%. The mean values of the conditions with parameter uncertainties were consistent with the results of certainty condition

and the most unfavorable values of uncertainty conditions were 1.1-1.3 of the results of certainty condition. Besides

the reduction in the tensile strength of the local joint had a significant effect on the response of the pipeline joint. On the basis of the numerical results

the prediction equations between the weak joint ratio and the peak joint opening under different seismic intensities were proposed.