【摘要】 将岩体和节理抽象为Kelvin黏弹性介质,建立谐波穿过黏弹性节理的传播模型,分析了谐波在黏弹性节理的透、反射系数和子波穿过节理后的波形变化规律.研究结果表明,黏弹性节理具有低通滤波特性,导致Ricker子波穿过黏弹性节理后,透射波振幅减小,主瓣不突出,波形在时域上变得更平缓;波形相关系数主要反映子波穿过黏弹性节理后发生的相位变化,而波形变化系数能综合反映子波的振幅和相位变化,因而两者描述子波波形变化时具有不同的变化规律;相对于切向刚度和切向黏性系数,节理的法向刚度和法向黏性系数对子波波形变化影响更大.更多还原

【Abstract】 The rock mass and joints are assumed as viscoelastic media to establish the propagation model of harmonic wave across viscoelastic joint. The transmission and reflection coefficient of harmonic wave across viscoelastic joint and waveform change rule of wavelet through joint are analyzed. The results indicate that viscoelastic joint has the low-pass filter property which leads to the decrease of the transmitted wave amplitude, the less prominent of the major lobe of waveform diagram of transmitted wave and the flatter of the waveform curve of transmitted wave after Ricker wavelet across viscoelastic joint; the phase change of wavelet propagation in viscoelastic joint can be described effectively by using correlation coefficient of waveform while the waveform change coefficient can reflect comprehensively the amplitude and phase change of wavelet, so the change rules are different when the wavelet waveform is analyzed by these two different coefficients;compared with shear stiffness and tangential viscosity coefficient, the normal stiffness and normal viscosity coefficient of the joints have greater effect on wavelet waveform change.更多还原