Evaluation of Field Shear Wave Velocity in Deep Soil Mixing Based on Laboratory Studies

Abstract

One of the reasons behind the stabilization of soft and problematic soil by deep soil mixing is to reduce the amplification of seismic waves which arrive to the ground surface and foundation of buildings. Therefore, it is important to correctly predict the dynamic properties of the improved ground. To address the dynamic properties of deep soil mixing, this paper evaluates the in-situ shear wave velocity of deep soil mixing (Vs-field) based on laboratory investigation (Vs-lab). The conversion factors, relating to the shear wave velocities of laboratory and field, have been obtained based on a variety of tests including bender element, pulse velocity, and low-amplitude dynamic tests in the resonance column. In this study, the effect of confinement and vertical stress on the dynamic properties of the base stabilized using deep soil mixing technology was evaluated. These effects were combined with the known disturbance and aging influence which is available in the literature. The research has shown that the most significant factors affecting the shear wave velocity are confinement stress and additional vertical load, which lead to 43% and 17.5% increase respectively.