岩巷掘进中电子雷管爆破振动信号的时频能量分析

挂帮矿地下开采环节伴随着爆破活动的进行,容易导致最终边坡失稳,为探究振动信号的时频能量分布特征,评估振动危害,在和静县备战铁矿开展了多组测振试验。对于监测所得振动数据,运用Hilbert-Huang变换(HHT)法,并结合小波软阈值去噪,从时间、频率和能量的角度对该挂帮矿振动信号进行了分析,同时运用EMD(Empirical Mode Decomposition)延期识别法和瞬时能量延期识别法,对电子雷管实际延期时间进行了识别。分析结果表明:(1)爆破能量主要集中在0～200 Hz频带范围内,主振频带为0～50 Hz;(2)爆破能量朝低频方向发展,在0～10 Hz频带内含有51.22%的能量,低频带内蕴含大部分能量,容易引发建(构)筑物自振,对挂帮矿边坡稳定性具有很大威胁;(3)在0.495 s和1.119 s,即掏槽孔爆破和辅助孔爆破时产生较大能量,因此建议为掏槽孔设置空孔,并适当减小第5段辅助孔装药量;(4)在常规延期下,EMD法和瞬时能量法的雷管段数识别率均为100%,对于实际延期时间的识别,EMD法识别精度为95.2%,瞬时能量法仅为82.6%。初步分析,这是因为EMD法自身进...

Time-frequency Energy Analysis of Electronic Detonator Blast Vibration Signals in Rock Tunneling #br#

The underground mining link of the hanging gang mine is accompanied by blasting activities,which can easily lead to final slope instability. In order to investigate the characteristics of the time-frequency energy distribution of vibration signals and assess the vibration hazards,several vibration measurement tests were carried out at the preparation iron ore mine in Hejing County. For the vibration data obtained from monitoring,the Hilbert-Huang transform ( HHT) method,combined with wavelet soft threshold denoising was applied to analyze the vibration signal of this hanging gang mine from the perspective of time,frequency and energy,and the EMD (Empirical Mode Decomposition) postponement identification method and instantaneous energy postponement identification method was applied to the electronic detonator The actual postponement time was identified. The analysis results show that:① The blasting energy is mainly concentrated in the frequency band of 0 ~ 200 Hz, and the main vibration band is 0 ~ 50 Hz;② The blasting energy develops in the direction of low frequency,and contains 51. 22% of energy in the frequency band of 0~ 10 Hz,and the low frequency band contains most of the energy,which is easy to trigger the self-vibration of the building ( structure) and has a great threat to the stability of the slope of the hanging gang mine;③ The blasting energy is in the range of 0. 495 s and 1. 119 s,i. e. ,the blasting of slotted holes and auxiliary holes generate more energy,so it is recommended to set empty holes for slotted holes and appropriately reduce the amount of auxiliary hole charge in section 5;④ Under the conventional extension,the recognition rate of detonator segments of EMD method and instantaneous energy method are 100%,and the recognition accuracy of actual extension time is 95. 2% for EMD method and only 82. 6% for instantaneous energy method. This is a preliminary analysis because the EMD method itself is not completely orthogonal decomposition,the analysis easily causes confusion between the modes,resulting in recognition accuracy not reaching 100%.