The use of elastic waves for determination of material properties has been in vogue for quite
some time. Ultrasonic waves have been used for the determination of dynamic elastic modull
of rock material in the laboratory. In the recent past the same technique has been extended to
soils. A better insight to the problem of P wave propagation, through materials like soil can be
had by considering it as two phase material – one phase consisting of solid frame and the other
phase of liquid or water. In the present work an effort has been made to relate static and dynamic
elastic modull, unconfined compressive strength and degree of saturation with P wave velocity. A
relatively new technique which is a combination of VSP and geotomography has been suggested
as a useful tool for subsurface investigations. Using this technique many features like soft pockets,
tunnels, buried pipe lines which are of interest to geotechnical engineers can e detected in a short
duration of time and more economically than by the traditional methods.