Prediction of shear wave velocities in soft to firm clays using consolidation tests

Abstract

The consolidation test is one of the most common laboratory tests in geotechnical investigations. It is mainly utilized to assess the clay operative constrained modulus, which is an essential parameter in the settlement calculations of foundations and embankments. Recently, the non-linear numerical modelling has become more common than ever in geotechnical engineering. The state-of-art advanced geotechnical analyses focus on consideration of the nonlinear variation of soil moduli with the stress and strain levels. One of the fundamental quantities in advanced non-linear geotechnical analyses is the small strain shear modulus. It is obtained by measuring the shear wave velocity using special tests or amendments to traditional tests. Such tests and/or amendments are generally much less common and more expensive than consolidation tests. In this paper, the shear wave velocity and small strain shear modulus of soft to firm clays are evaluated from results of consolidation tests. The site-specific constants that relate the void ratio to the in-situ shear wave velocity is attained from the undisturbed virgin compression curve acquired from a consolidation test. The in-situ shear wave velocities and small strain shear moduli are concluded from the water content measurements. The proposed approach is validated by analysing two well-reported case studies; namely Ariake and Singapore clays. The results of the analyses show the viability of the proposed approach as the estimated moduli compare favourably with the values inferred from the field measurements.