Abstract: During the excavation process of underground cavern,the effect of the excavation blasting vibration on the surrounding rock and the supporting project can not be neglected.The 3N cavern in the Jinzhou underground cavern is 934 m long.Based on the spatial effect of seismic wave propagation,the 3N cavern is divided into three sections,obtaining the speed attenuation law of each section.The results showed that the decay rate of the front section is the fastest,followed by the middle,and the final section is the slowest.According to the safe vibration velocity of the blasting vibration of the new pouring concrete,the safety distance in the front,middle and the final section of the cavern were determined.The results provide a theoretical basis for selecting the safety distance of other cavern support.

Key words: Underground cavern, Blasting vibration, Speed attenuation law, Safety distance