Geophysical surveying methods for soft soil

Geophysical surveying methods are becoming common in geotechnical problems involving very small strains. It has been reported that the wave velocities from different geophysical surveying methods may differ. This has raised questions as to the validity of the results. In this paper two geophysical surveying methods, the crosshole method and the downhole method, using both P and S waves will be discussed. Surveying results from two soft soil sites in Singapore will be presented and the dynamic moduli determined from the wave velocities will be compared. Finally comparisons with deformation modulus values derived from conventional soil tests will be made.