廉玉广, 李江华, 焦 阳, 李梓毓, 王国库. 对称介质中陷落柱槽波地震波场响应特征研究[J]. 煤矿安全, 2023, 54(2): 181-188.
    引用本文: 廉玉广, 李江华, 焦 阳, 李梓毓, 王国库. 对称介质中陷落柱槽波地震波场响应特征研究[J]. 煤矿安全, 2023, 54(2): 181-188.
    LIAN Yuguang, LI Jianghua, JIAO Yang, LI Ziyu, WANG Guoku. Response characteristic of in-seam seismic wave field for collapse column in symmetrical medium[J]. Safety in Coal Mines, 2023, 54(2): 181-188.
    Citation: LIAN Yuguang, LI Jianghua, JIAO Yang, LI Ziyu, WANG Guoku. Response characteristic of in-seam seismic wave field for collapse column in symmetrical medium[J]. Safety in Coal Mines, 2023, 54(2): 181-188.

    对称介质中陷落柱槽波地震波场响应特征研究

    Response characteristic of in-seam seismic wave field for collapse column in symmetrical medium

    • 摘要: 华北型石炭二叠系煤田中陷落柱较发育,通常会破坏地层的完整性,在孕育发展过程改变了围岩的力学特性和声学特征;通过岩石单轴加载条件下波速测试,获得岩石加载塑性变形前波速与应力的关系;基于物性参数测试结果建立三层对称均匀介质的数值计算模型,采用有限差分法对弹性波动方程进行全波场正演模拟,并在模型中部设置陷落柱,获得波场快照、地震波记录及频散曲线,采用速度和能量衰减系数CT分析法对槽波地震波场进行反演,研究了不同陷落柱物性参数及观测系统布置参数对反演结果的影响。结果表明:地震波场随着传播距离的增大而减弱,遇到陷落柱时槽波信号明显减弱甚至消失;陷落柱波速大于围岩或小于煤层时,形成明显的绕射槽波,Airy相发生跳动现象;陷落柱波速小于煤层时表现为低速异常,而低速或高速的陷落柱均产生明显的能量衰减异常;现场观测系统布置时炮间距和道间距可选为20 m。

       

      Abstract: Collapse columns which can usually destroy the integrity of strata are widespread in the Carboniferous and Permian coalfields for North China type. The incubation and development process of collapse column could change the mechanical property and acoustic feature of surrounding rock. Rock wave velocity was tested under uniaxial loading and the relationship of wave velocity and stress was obtained before plastic deformation. Based on the physical property parameters of rock and coal, homogeneous medium for three symmetrical layers was established. For the full-wave-fields forward modeling, elastic wave equations were analyzed through finite difference method. Wave field snapshot, plane-wave seismogram and frequency dispersion curve were obtained after analysis for the collapse column in the model. In-seam seismic wave field was inversed through velocity analysis and CT analysis of energy attenuation coefficient. The effect on inversion result was researched for different physical property parameters of collapse column and observing system parameters. The research results showed that seismic wave field was decayed with the increase of propagation distance. In-seam seismic wave signal was weakened or even disappeared when the collapse column is encountered. When the wave velocity of the collapse column is larger than that of the surrounding rock or smaller than that of the coal seam, an obvious diffraction in-seam wave is formed and the Airy phase pulsates. When the wave velocity of the collapse column is less than that of the coal seam, it is characterized by low speed anomaly, and the collapse column with low speed or high speed produces obvious energy attenuation anomaly. When the field observation system is arranged, the gun spacing and channel spacing can be selected as 20 m.

       

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