Stresses in fluid-saturated porous half-space due to normal and tangential loadings (Q1068602)

This paper deals with the disturbance caused by the harmonic time dependent normal and tangential forces acting on a fluid-saturated porous elastic medium. Two cases have been dealt with separately. The expressions for stresses and displacements have been derived in closed forms in both cases. The inertia coupling between the fluid and solid are neglected. Numerical computations have been done for the stress distribution and it is shown in graphs that the nature of stresses changes rapidly with depth and the velocity of disturbance produced by the time dependent harmonic loads. The critical velocity of disturbance to cause fracture in the medium has also been numerically calculated on the basis of the parameters formulated by Biot for the fluid-saturated poroelastic medium in low frequency range, and it is concluded that fluid-saturated material is more stable than the corresponding elastic material. The frequency equation for Rayleigh waves in fluid saturated porous solid has also been derived and is shown to coincide with the secular equation as obtained by \textit{H. Deresiewicz} [Bull. Seis. Soc. Am. 52, 627-638 (1962)] as a particular case. Further it has been shown that the results agree with those for the common elastic half space.