Pulse Propagation in a Poroelastic Solid

The problem of a stress pulse applied to a semi-infinite region of a poroelastic medium is examined to determine the effect of a stress pulse on equipment located underground. If dissipation is neglected, an applied step pulse splits into two pulses that propagate unchanged in shape, each moving at one of the dilatational speeds of the medium. If dissipation is included, the step pulse splits into a “smeared-out” component and a component that retains the sharp front. The latter component travels at a speed that would occur if the fluid and solid were locked together. It is concluded that linear poroelastic dissipative mechanisms are insufficient in themselves to yield a substantial reduction in accelerations for equipment buried in a saturated soil.