Study on vibration propagation law of frozen clay blasting in deep mine shaft

In order to study the propagation law of explosion stress waves in frozen clay blasting and reduce the vibration damage to frozen pipe and shaft wall,blasting experiments were carried out in the frozen clay excavation section of the vertical shaft.Through the blasting vibration test at -690 m downhole,the vertical,horizontal radial and horizontal tangential vibration velocities in the frozen clay were obtained,and the Sadowski formula is used to fit them.The velocity presents a difference,where vertical vibration velocity>radial vibration velocity>tangential vibration velocity.The wavelet packet analysis was carried out on the blasting vibration signals of frozen clay and it is concluded that the blasting distance is within 0-6.243 m,the total energy of the three components shows the law of Ez>Ex>Ey,and the blasting vibration frequency is mainly concentrated within 250 Hz.The energy ratio of blasting vibration signal attenuates oscillatingly in the high frequency range,while the low frequency attenuation decays slowly and tends to be stable.The total energy of blasting vibration generally decreases sharply at 0 and 187 Hz,and the energy ratio increases significantly around 218 Hz.The vertical energy change is more significant than the radial and tangential energy changes.This research results have certain guiding significance and application value for blasting and vibration control of frozen clay in vertical shafts.