A Vibration Prediction Model of Open Step Single Hole Blasting

To solve the non-stationary problems of vibration wave randomness, the intensity and frequency existed in blasting vibration, a step single hole blasting vibration prediction model was constructed to reflect truly the characteristics of blasting vibration waveforms. Firstly, a frequency function of the model was determined based on modulating white noise, describing the non-stationary frequency of the vibration waveform with time-varying nature of angular frequency. Then, screening the intensity envelope function, the Gamma function was selected to describe the non-stationary intensity of blasting vibration waveforms, improving the simulation accuracy of the prediction model with the high pass filtering process in the low frequency range. And then, taking the time-history frequency consistency of the on-site measured waveform and the predicted model as restrict condition, and taking the linearly relation as the relationship of the damping ratio and the irregularity index, the frequency parameters (η, ξ, γ) of the model were designed. Based on the accumulated energy of on-site measured waveforms as a constraint condition, the strength parameters (I₀, α, β) were determined. The results show that the peak vibration velocity and main frequency of the output waveform of the model can agreement better with the characteristics of the on-site measured waveform, verifying the correctness and effectiveness of the constructed prediction model.