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在以前共振声谱实验工作基础上,对10块中高孔隙度(22%~30%)的饱和人工岩样分别在圆柱形共振腔体形成的低阶模式共振声谱进行了实验测量,并研究了岩心孔隙度对共振声谱的影响.实验结果表明,岩样位置由谐振腔顶部变化到中部,共振频率逐渐增大,共振幅度逐渐降低.在谐振腔中部,共振频率增至到最大而共振幅度减至最小;随着孔隙度增加,共振频率降低,共振幅度减小,衰减增大.另外,利用体积平均模型,对圆柱形谐振腔中具有岩石样品的共振频率进行了理论分析和数值模拟,理论结果表明,随着岩样位置由谐振腔的顶部变化到中部,共振频率逐渐增大且在中部时最大;岩样孔隙对共振频率有影响,在谐振腔中部共振频率随着孔隙度的增大而减少.以上结论已被理论和实验结果所证实.为利用低阶模式共振声谱法检测岩石样品的孔隙和裂缝特征提供了理论和实验依据.
Based on the experimental work of previous resonant spectroscopy, 10 low-order mode resonance spectra formed by a cylindrical resonant cavity were measured and measured on 10 saturated artificial rock samples with medium-high porosity (22% -30%), respectively. The results show that the position of rock sample changes from the top to the middle of the cavity, the resonance frequency gradually increases and the amplitude of the resonance decreases gradually. In the middle of the cavity, the resonance frequency increases to the maximum and resonates With the increase of porosity, the resonance frequency decreases, the amplitude of resonance decreases and the attenuation increases.In addition, the resonance frequency of a rock sample with cylindrical cavity is theoretically analyzed and numerically simulated by the volume average model The theoretical results show that the resonance frequency increases gradually with the rock sample position changing from the top to the middle of the resonator, and the largest in the middle. The rock porosity affects the resonance frequency. The resonant frequency in the middle of the resonator varies with the porosity The above conclusions have been confirmed by the theoretical and experimental results.It provides the theoretical and experimental basis for the detection of the pore and fracture characteristics of rock samples by the low-order mode resonance spectroscopy.