摘要
基于Biot的孔隙介质理论研究了横观各向同性含液饱和多孔介质中瑞利波的传播特性.考虑介质内的流体特性及固体颗粒的可压缩性,导出了广义瑞利波的三维复特征方程,给出了瑞利波的存在条件.并且,通过数值计算讨论了横观各向同性含液饱和多孔介质中的瑞利波波速、质点的运动轨迹和频散特性、以及流体黏度对瑞利波传播特性的影响.
Fluid phase in the porous media has great influence on the propagation characteristic of Rayleigh waves. Though many researches have been carried out on the propagation of Rayleigh waves in the fluid saturated porous media, the emphasis is mainly focused on the isotropic solid skeleton and the non-viscous fluid. The effects of fluid viscosity on the propagation characteristic of Rayleigh waves are seldom calculated or discussed. However, clarification of the characteristic of Rayleigh waves in the anisotropic viscous-fluid saturated porous media have significant meaning in many practical fields such as oil extraction engineering, protection and control of pollution in geophysics and hydrology.In this paper, the propagation characteristic of Rayleigh waves in transversely isotropic viscous-fluid saturated porous media is studied based on Biot's theory under the assumption that the symmetry axes of the transversely isotropic skeleton and dynamic permeability are parallel to the vertical axis of the borehole. With consideration of the dissipation due to the fluid viscosity and the compressibility of the solid grains, the three-dimensional complex characteristic equation of Rayleigh waves in the transversely isotropic fluid saturated porous media for the real frequency domain is derived by introducing the dynamic permeability, and the existing conditions are also given. The Rayleigh wave speeds and particle traces in different sagittal planes are calculated. The effects of the porosity and the fluid viscosity on the propagation of Rayleigh waves are numerically simulated. The analytical results show that when the fluid viscosity is taken into account, the Rayleigh wave speed is frequency dependence, which is different from the situation when the solid skeleton is isotropic or the fluid viscosity is omitted. The Rayleigh wave speed is not only decided by the velocity of fast and transverse waves in the solid skeleton, but also affected by the velocity of the slow waves.
出处
《力学学报》
EI
CSCD
北大核心
2003年第1期100-104,共5页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助(19832010
10025212).
