Vibration Response and Safety Control of Frame-shear Structure Adjacent to Mine Blasting

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 PPV_x and PPV_y are not more than 0.17 cm/s and 0.213 cm/s, respectively, and the elevation has little influence. The PPV_z 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 PPV_s. The elevation difference is not significant for the PPV_x but significant for the PPV_y and PPV_z. 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.