The prediction of the Standard Penetration Test (SPT-N) blow count using p-wave velocities
(Vp) has been barely studied. Traditionally, the field s-wave velocities (Vs) have been the aim of the most of
the efforts to correlate seismic behavior and penetration resistance properties of soils. Nevertheless, this new
approach will expand the correlation to the field of primary waves. The potential use of this correlation will
be useful in the search for new easy, non-invasive and non-expensive methods to probe soil properties in underdeveloped and developing countries, in which deep-boring machinery is hard to find or too expensive to
use. After a large soil testing program in Costa Rica, in volcanic soils, p-waves were used to develop a correlation between p-wave velocity and NSPT in the investigated soils.
