Study on the vibration prediction model of step group hole blasting considering non-stationarity
ObjectiveThis study addresses a key problem in the prediction of blasting vibration of a group of holes in a step, that is, it is difficult to fully reflect the stochastic nature of blasting vibration (intensity-frequency non-smoothness characteristics) in the traditional method, resulting in insuff...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Editorial Department of Journal of Sichuan University (Engineering Science Edition)
2025-01-01
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| Series: | 工程科学与技术 |
| Subjects: | |
| Online Access: | http://jsuese.scu.edu.cn/thesisDetails#10.12454/j.jsuese.202400981 |
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| Summary: | ObjectiveThis study addresses a key problem in the prediction of blasting vibration of a group of holes in a step, that is, it is difficult to fully reflect the stochastic nature of blasting vibration (intensity-frequency non-smoothness characteristics) in the traditional method, resulting in insufficient prediction accuracy, especially in the superposition of vibration waveforms of a group of holes in the blasting vibration fails to accurately reflect the influence of the randomness of the sub-wave phase and the cumulative effect. In order to solve this problem, the study aims to establish a single-hole blasting vibration prediction model that can reflect the randomness and non-stationary characteristics of blasting vibration, and construct a prediction model applicable to group-hole blasting on this basis. The necessity of this work lies in the fact that blasting vibration, as the most significant hazard in step blasting, directly threatens the safety of neighboring buildings and personnel, and accurate prediction of its characteristics is crucial for blasting engineering design and risk control.MethodsThis study takes the similarity between natural seismic wave and blasting vibration as the theoretical basis, uses the principle of modulated white noise to construct the frequency equation, processes the white noise through the filter and introduces the time-varying damping ratio and the intrinsic angular frequency, so as to make the frequency present non-stationarity; at the same time, the gamma function is selected as the intensity equation, which expresses the intensity non-stationarity with its ability to regulate the shape of the curve, and the product of the two constitutes the prediction model of single-hole blasting vibration X(t)=x(t)*A(t). In order to eliminate the effect of model randomness, the 95% confidence interval is used to determine the optimal number of cycles (500 times), and the measured waveforms in the field as a sample, through the residual similarity to quantify the match between the simulated waveforms and the measured waveforms. The parameters were determined by trial-and-error method to obtain the approximation interval, and then the optimal parameter combinations were optimized by orthogonal test-polar deviation analysis. Subsequently, a group-hole blasting vibration prediction model was constructed based on the single-hole model, combined with Anderson's linear superposition principle, and taking into account the delay time of the holes and the proportion coefficients of the charge volume.Results and Discussions In the single-hole blasting vibration monitoring experiment of an open-pit copper mine, the peak vibration velocity error predicted by the single-hole blasting vibration prediction model is 2%, and the main frequency is completely consistent with the measured value, which is significantly better than Sadowski's formula (43% error in the peak vibration velocity and 12% error in the main frequency). The residual similarity of the simulated waveforms output from the model reaches 0.5195, which verifies its effectiveness and superiority. The constructed group hole blasting vibration prediction model, applied to the group hole blasting vibration monitoring experiments, the predicted peak vibration velocity of 11.4649cm/s, and the measured value of 10.9605cm/s error is only 4%; the predicted value of the main frequency is 29.0023Hz, and the measured value of 28.3688Hz error is only 2%, and the measured waveform is highly consistent. This shows that the model proposed in this paper can effectively solve the problems of randomness and non-stationarity that are not fully considered in the traditional method, and has strong applicability and reliability.ConclusionsIn this study, a single-hole blasting vibration prediction model considering non-stationarity was successfully established and extended to group-hole blasting vibration prediction by optimizing Anderson's linear superposition method, which reveals the randomness of blasting vibration and intensity-frequency non-stationarity. The model expresses the frequency and intensity non-stationarity through modulated white noise and gamma function, and optimizes the parameters with residual similarity and orthogonal-pole difference analysis, finally realizing high accuracy prediction. This result theoretically deepens the understanding of the non-stationary characteristics of blasting vibration, and proposes an innovative model and parameter optimization method; in application, it provides an accurate vibration prediction method for step blasting engineering, which can effectively guide the blasting design and reduce the vibration hazards, and has significant scientific significance and engineering value. |
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| ISSN: | 2096-3246 |