Correlation between the shear-wave velocity and tip resistance of quartz sand in a centrifuge

Abstract

In centrifuge modeling, it is important to evaluate the in-flight strength and stiffness parameters of the soil model to understand soil behavior. Both the shear-wave velocity (Vs) and cone tip resistance (qc) are commonly used to determine the stiffness and strength characteristics of soils. If direct Vs measurement is not available, the qc profile measured in the centrifuge can be used as an alternative method of estimation, although direct Vs measurement is preferred. In this paper, a series of carefully controlled cone penetration tests and Vs measurement tests are simultaneously conducted in uniform silica sand during centrifuge operation. The tests are undertaken in loose to dense sandy samples under both dry and saturated conditions. Laboratory resonant column tests are performed to validate the small-strain shear modulus (G0) obtained from centrifuge tests. Measured qc profiles at shallow penetration depth are corrected to consider the difference of cone diameters between a field standard cone and centrifuge miniature cone. Finally, new empirical correlations between the Vs and qc for normally consolidated, uncemented silica sand are proposed and compared with previously reported in situ relationships.