(1. State Key Laboratory of Water Resources and Hydropower Engineering Science，Wuhan University，Wuhan，Hubei 430072，China；2. Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Ministry of Education，Wuhan University，
Wuhan，Hubei 430072，China)
Abstract：Frequency analysis of blast vibration is one of the important foundations for developing the control technology of blast vibration damage. Based on the spectrum expression of vibration with a damping term for the spherical charge in tough rock mass and LS-DYNA numerical simulations，the attenuation of dominant frequency and average frequency of blast vibration were analyzed. The attenuation of dominant frequency and average frequency of blast vibration induced by cylindrical charge were studied with the numerical simulations. The results show that for both the spherical or cylindrical charges，the dominant frequency of blast vibration does not attenuate strictly with the increasing of distance to the blast site. Both the multimodal structures of vibration spectrum and the difference of decay rate between the high-frequency and the low-frequency contribute to the mutation or fluctuation at some distance during the frequency attenuation. The average frequency has the pattern of regular attenuation. Theoretical analysis results were validated by the empirical data gotten from engineering.
2014, Vol. 33 
