波在饱含流体的孔隙介质中的传播问题

考虑到流体的可压缩性,笔者进一步发展了以前的结果。引进了准微观连续条件的概念,直接联合应用流体动力学方程和固体的弹性或粘弹性力学方程,即得到了此种介质的动力学方程组,其中直接引用了流体和固体的弹性（或粘弹性）系数,较之Biot从物理考虑而建立的应力-应变关系中的后两个常数Q、R具有更明确的物理意义,因而更便于用常规的方法确定。证明了,此种无限介质中通常具有两种P波和一种S波,且具阻尼和频散效应。对于几种极端情况可以明确地得到固体波和流体波,有助于近似地解释一些地球物理和声学现象。文中还指出了区分两种典型的计算模型的重要意义。

PROBLEMS OF WAVE PROPAGATION IN POROUS,FLUID-SATURATED MEDIA

A further development of the theory on the wave propagation in porous, fluid-saturated media presented by the writer in works （1,2） is made in this paper by taking account of the compressibility of fluids. After introducing an idea of quasi-microscopic continuous conditions, the basic system of dynamic equations of such media is established by combining the equations of the compressible fluid dynamics with those of the theory of elasticity or viscoelasticity. That there are two P waves; and one S wave was also proved.It is pointed out that the two phased media can be simplified by two ideal models according to their disperse state, seepage ability, constituent arrangement structure, etc.. For the case of our concern, model 2, the media are mechanically coupled by the seepage force, which can be assumed to obey Darcy's law, and the compatibility conditions in a unit volume. If the seepage flow can take place freely, for example, the case of saturated gravel strata as well as porous piastie materials, it is shown that one hydrodynamic wave into fluids and two solid stress waves into the solid skeleton can be set up, which, in particular cases, are of value to explain some geophysical and acoustic phenomena. In general cases, there are damping and dispersion effects.The significance of carefully distinguishing the two physical models is also discussed.