基于透射槽波的采煤工作面陷落柱探测模拟研究
Simulation Study on Detection of Collapse Column in Coal Face Based on Transmitted Slot Wave
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摘要: 煤层中陷落柱严重影响采煤作业,会引起突水、瓦斯突出等安全事故,为此,基于物理模拟技术,根据煤层陷落柱的结构、物性参数以及声学特性特点,选择了煤粉、石膏、水泥为原料,设计并制作了“岩-煤(含陷落柱)-岩”3层煤层物理模型来模拟。根据物理模拟的相似原理,选择合适的声波频率,以可控频率振幅和可选子波的声波发射仪激发振动模拟槽波激发震源,利用透射法在煤层物理模型中采集槽波数据,模拟采煤工作面内陷落柱槽波探测装置,研究采煤工作面内陷落柱的透射槽波探测方法。利用实验透射槽波数据,计算出各通道的振幅能量衰减系数,利用槽波数据波形分析波速,使用平滑伪魏格纳威利分布(SPWVD)时频分析方法,最终确定陷落柱的存在位置。结果表明:对透射槽波的速度分析,利用SPWVD分析透射槽波能量特征,根据槽波最大振幅衰减系数,可以有效识别采煤工作面内的陷落柱。Abstract: The existence of subsidence column causes difficulties in coal mining, therefore, according to the structure, physical parameters and acoustic characteristics of coal seam collapse pillar, the coal powder, gypsum and cement are selected as raw materials, and the “rock-coal (containing collapse pillar)-rock” three-layer model is designed to study the coal seam with collapse pillar. The acoustic instrument controls the amplitude and frequency of the source, and the channel wave data is collected by transmission method. The amplitude energy attenuation coefficients of each channel are calculated by using the transmitted slot wave data, the wave velocity is analyzed by using the slot wave data waveform, and the existence position of collapse column is determined by using the time-frequency analysis method of Smoothed Pseudo Wigner-Ville distribution (SPWVD). The results show that the collapse column in the coal face can be effectively identified by analyzing the velocity of the transmitted slot wave and using SPWVD to analyze the energy characteristics of the transmitted slot wave, the collapse column in coal face can be identified effectively based on the maximum amplitude attenuation coefficient of slot wave.