Biot耦合模式波的动力学特征

通过数值计算重点论述了低频务件下介质不同区域(弹性区、粘性区、孔隙区(被流体充填或不充填))对波传播的作用，分析了在均匀的、完全各向同性介质中Blot耦合模式波在低频条件下的特点。发现：(1)慢纵波相速度存在临界孔隙度现象，临界孔隙度是慢纵波相速度的盲点。(2)低频、高孔隙度条件更有利于慢纵波的观测。(3)低频条件下，快纵波、横波相速度与渗透率无关；而快纵波、横波损耗因子受渗透率影响较大。

DYNAMIC CHARACTERISTICS OF SEISMIC WAVES WITH BIOT COUPLING

With numerical evaluation, the effects of different parts of medium, such as elastic, viscous and porous filled with or without fluid, on the wave propagation especially in the range of low frequency band are discussed. Characteristics of seismic wave with Biot coupling are analyzed in the homogeneous and isotropic medium. The results show: (1) the phenomenon of critical porosity exists about the phase-velocity of slow P-wave in and the critical porosity is the blind spot of the phase-velocity of slow P-wave. (2) It is easy to observe slow P-wave in the condition of large porosity and low frequency band. (3) In the range of low frequency band, the phase-velocity of P- and S-wave is independent of penetrability, while the loss factor of P- and S-wave strongly depends on penetrability.