Use of laboratory shear wave velocity measurement to enhance in-situ data

Shear wave velocity (V s ) plays a central role in soil dynamics and is widely used in seismic site classification, liquefaction assessment, and earthquake stability analysis. One of its distinguishing features is that it directly relates to small-strain shear modulus (G = ρVs 2 ), making it the only mechanical property that can be consistently measured in both field and laboratory settings. Field measurements of V s are particularly valuable because they capture soil stiffness in its natural, undisturbed state, offering insight into in-situ density conditions. Despite its relevance, V s remains underutilized in geotechnical practice. Given its sensitivity to factors such as soil density, stress conditions, and preloading history, accurate measurement of V s can provide a robust and reliable geotechnical parameter. Several studies have reported that shear wave velocities obtained from laboratory tests tend to be lower than those measured in the field. This discrepancy is commonly attributed to disturbances caused by the sample extraction process. Such disturbance effects are not limited to Vs measurements; they also impact other geotechnical properties assessed in the lab, such as undrained shear strength and pre-consolidation pressure. To address this issue, it is essential not only to work with high-quality clay specimens but also to develop strategies for quantifying and correcting sampling-induced alterations. This study introduces a novel method to evaluate the extent of disturbance resulting from sampling and specimen handling. It further proposes a correction approach for laboratory-derived stiffness parameters. These corrected values are then benchmarked against in-situ measurements obtained under undisturbed conditions. Finally, the adjusted laboratory data are integrated to enhance the interpretation of field measurements in stres-strain analyses.