PDF
Full
Outline
In order to solve the problem that excessive blasting vibration affects the safety of village buildings (structures) on the earth's surface during the mining process of an underground orebody, the inter-hole delays of 8 ms, 10 ms, 12 ms, 14ms and 18ms and inter-row delay of 100 ms were selected for tests in the #63113 ore room of the orebody III in the mine. By combining the actual situation of the site and the empirical formula, the natural vibration frequency of the brick-concrete buildings with 1 to 2 floors in the village was 7.63~13.23 Hz. The blasting vibration data was collected on site and HHT transformation was applied on the measured blasting vibration signals by MATLAB. The characteristics of the signals were then analyzed from the perspectives of time domain, frequency domain and energy. The highly adaptive EMD decomposition was used to decompose the original vibration signal into the IMF components which were transformed by 10-layer db8 wavelet transform and the proportion of energy in the total energy of the frequency band 7.8~15.7 Hz of level 9 was summarized. The three-dimensional Hilbert spectrum and marginal spectrum were obtained by Hilbert transformation of the reconstructed signal with the IMF components. Through EMD decomposition and wavelet transform research on the blasting vibration signals, it is concluded that the three-direction energy ratio corresponding to the 12 ms delay time at No.3 measuring point is reduced by 14.07%, 24.89% and 6.26%, respectively. The experiments show that the problem that the problem that the low frequency energy takes a large proportion in the total energy can be improved by optimizing the inter-hole delay, and the resonance effect can be effectively avoided. By comparing the Hilbert marginal spectrum and the three-dimensional Hilbert spectrum with different delay times, the main vibration frequency and the maximum instantaneous energy of the blasting with an inter-hole delay of 12 ms appear 200 ms after the detonation, concentrated in the range of 30~40 Hz which is higher than the natural vibration band of the buildings, and thus have the least influence on the structures.
PDF
77
35
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
