Understanding blast vibration propagation mechanisms in underground stopes with complex roadway configurations is crucial for ensuring safe blasting operations. This study presents a comparative analysis of blast-induced vibration characteristics in the deep mining operations at the Tonglushan Copper-Iron Mine. Through systematic field blasting tests, the vibration velocity, dominant frequency, and blasting energy were measured at monitoring points in the upper-level and current-level drilling roadways. To enhance the reliability and completeness of vibration data, five supplementary field blasting tests were systematically conducted in coordination with the operational schedule of Tonglushan Copper-Iron Mine′s production activities. Vibration monitoring stations were strategically established at multiple positions within both the current-level and upper-level drilling roadways to capture comprehensive blast-induced dynamic responses. The study employed the Sadovsky formula to systematically characterize blast vibration propagation patterns in both upper-level and current-level drilling roadways of the underground stope. This analytical approach established critical relationships for vibration attenuation that directly informed the engineering design of safe blasting parameters for site operations. Key findings reveal that, at comparable blast-center distances, high-frequency components exhibit significantly greater attenuation than low-frequency signals when interacting with roadway structures and dissipate more energy during stress wave propagation through rock mass matrices. Furthermore, the segmental maximum instantaneous energy measurements show comparable values between the upper-level drilling roadway. However, the upper-level drilling roadway exhibits significantly higher cumulative blasting energy than the current-level drilling roadway, attributed to longer instantaneous energy durations in each segment. Additionally, the upper-level drilling roadway shows consistently lower triaxial peak vibration velocities and lower attenuation rates than the upper-level roadway.
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The impact of blasting vibration on surrounding buildings has been widely concerned. Based on the deep hole bench blasting project of Changtan Open-pit Coal Mine, the characteristics of the adjacent 11-story frame-shear structure office building are comprehensively analyzed. After several blasting vibration tests, the distribution characteristics of vibration velocity and main frequency in different directions were analyzed. The significance of elevation difference on vibration velocity in various directions was obtained through single-factor analysis. Finally, based on the dimensional analysis method, a vibration velocity prediction model under the influence of multiple factors was studied, proposed, and applied to the blasting safety charge design. The main conclusions are as follows: with the increase of floors, the primary vibration direction changes from horizontal radial(X) to horizontal tangential(Y), and finally to vertical(Z). In most working conditions, the PPVx and PPVy are not more than 0.17 cm/s and 0.213 cm/s, respectively, and the elevation has little influence. The PPVz is concentrated in 0.05~0.41 cm/s, and the elevation amplification effect is significant in 7~11 layers. The maximum charge per delay, total charge amount, and horizontal distance are substantial for the three-axis PPVs. The elevation difference is not significant for the PPVx but significant for the PPVy and PPVz. The main vibration frequency is concentrated in 3~12 Hz, and some reach 16~30 Hz. Based on the vibration prediction model for the office building, combined with the blasting safety regulations and the blasting parameters under the most dangerous working conditions, the total charge of the bottom blasting should be within 10 267 kg, and the total charge of the deep hole bench blasting should be between 8268~8883 kg.
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