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为探索综放开采中煤岩性状的识别方法,根据放顶煤开采中煤、矸石、顶板岩石物理与力学参数的不同,垮落时冲击液压支架后尾梁产生的声压信号在幅值、能量及频率上会存在差异.据此自行设计现场信号采集实验并拾取到大量真实顶煤垮落、矸石垮落、顶板岩石垮落三种工况下垮落物冲击后尾梁时的声压信号.由于信号混有现场刮板输送机的工作噪声,利用小波降噪对信号进行降噪处理.通过对降噪后的声压信号进行六层小波包分解并运用频带能量分析法提取第6层64个频带的归一化能量,并进行能量百分比分布及统计指标分析.研究结果表明:3种工况下的声压信号各频带的能量以及在0~1 250 Hz、0~2 500 Hz内的能量分布特征以及对统计指标的敏感程度不同.
In order to explore the identification method of coal and rock properties in fully mechanized top coal caving mining, according to the different physical and mechanical parameters of coal, gangue and roof in caving coal mining, Energy and frequency will be different.According to the self-designed field signal acquisition experiments and pick up a lot of real top coal caving, rock collapse, roof rock caving three kinds of conditions under the impact of the collapse of the rear beam when the sound pressure Signal.With the signal mixed with the working noise of on-site scraper conveyor, the signal is denoised by wavelet denoising.At the 6th wavelet packet decomposition of the noise-reduced signal and the band energy analysis method, The normalized energy of 64 bands and the energy percentage distribution as well as statistical index analysis.The results show that the energy of each band of the sound pressure signal under the three conditions and the energy at 0 ~ 1 250 Hz, 0 ~ 2 500 Hz Within the energy distribution characteristics and the sensitivity of different statistical indicators.