Abstract
SPT N-value and S-wave velocities for gravelly soils with widely varying grain size distribution were measured in a large container test and formulated as functions of gradation, relative density and confining stresses. These values have been found to be very sensitive to the difference in gradation. It has also been found that well-graded gravelly soils, despite the much smaller void ratio than sand, can have an N-value and shear wave velocity as low as loose sand if it is loosely deposited. It has also been found that the formulae can readily estimate N-values with the factor of 1.5∼1/1.5 and S-wave velocity with that of 1.2∼1/1.2 for a wide range of gravelly soils and can give a direct relationship between the two variables which is consistent with previous research based on field data.
