Characterization of Sandy Soils Using CPT and DMT

Abstract

A site investigation campaign using cone penetration test (CPT) and dilatometer test (DMT) was carried out on three sandy soils of Japan. Two of these sites are natural sand deposits and the third one is a sand fill reclaimed about twenty years ago. On two sites, high quality samples were taken using the freezing sampling method so that the measured value of the relative density D r is assumed to be accurate. Seismic cone tests were also performed in order to measure the shear modulus at a very small strain level in the order of 10 –5 . Data from CPT and DMT were related to design parameters using correlations established from calibration chamber tests. The main conclusions obtained in the present study are: 1) existing soil classification methods using CPT and DMT data can be applied to the investigated sites; 2) D r values predicted from relationships linking D r to q t / ( p' v 0 ) 0.5 , where q t is the point resistance from CPT and p' v 0 is the vertical effective overburden pressure, seem to be in good agreement with actual values of D r ; 3) D r can also be well predicted using DMT horizontal stress index K D values, and 4) the ratios of the shear modulus G sc from the seismic cone to q t or E D from DMT, G sc /q t or G SC /E D decrease with increasing values of the relative density D r .