The influence of impact loading generated during the excavation blasting process on a buried gas pipeline near the blasting source has been widely concerned as a major safety issue in the engineering construction of an urban underground space.Based on a specific construction case,this issue is studied with a fluid-solid coupling model considering soil,pipeline and rock by using the dynamic finite element software LS-DYNA.The distribution laws of the effective stresses and the resultant velocities of vibration on the two sides of the pipeline towards and away from the blasting source are analyzed with four different wall thicknesses(δ) of 0.02 m,0.04 m,0.06 m and 0.08 m.At the same time,the attenuation characteristics of the peak blasting vibration velocities on the ground and the two sides of the pipeline towards and away from the blasting source are further investigated based on the established coupling model.The results present a nonlinear attenuation law of the effective stresses and the resultant velocities of vibration with the increase of the pipe wall thickness.Specifically,Moreover,the local peak stress on the side of the pipeline away from the blasting source is significantly higher than that on the side towards the blasting source,whereas the resultant vibration velocities on the side of the pipeline towards the blasting source is significantly higher than that on the side away from the blasting source.Now that the pipe wall thickness increases by an increment of Δδ=0.02 m,the attenuation rates of the peak effective stresses on both sides(towards and away) of the pipeline are κ1=25.2%,19.2%,10.7% and κ2=50%,25%,13.3%,respectively.For the four different wall thicknesses,the average attenuation rates of peak particle vibration velocities from the side of the pipeline towards the blasting source to the side of the pipeline away from the blasting source and from the side of the pipeline away from the blasting source to ground are η1=24.6%,18.96%,15.04%,14.78% and η2=73.46%,69.4%,66.52%,63.6% respectively.However,the change of attenuation coefficient is significantly smaller than the attenuation rate.Therefore,it is no longer accurate to use the Sadovsky formula,which needs to be corrected,to predict the vibration velocities of pipelines in such inhomogeneous geological conditions.