Stress Dependency of Shear-Wave Velocity Measurements in Soils

摘要

Based on an extensive in situ shear-wave velocity (V_S) database, this study aims to not only examine the stress-dependent characteristics of in situ V_S from a generalized V_S-stress model [V_S = α × (σ'_c)~β], but also provide valuable reference information on site-specific stress-dependency of V_S for global geotechnical sites. For in situ V_S, the site-specific material constants (α and β) at each site had wider ranges when compared to typical values reported from laboratory tests. This is mainly attributed to different test conditions and inherent in situ site characteristics. The in situ-based site-specific material constants in this study are compared with laboratory-based material constants suggested in previous studies. Evidently, each α-β trend varies on laboratory tests and in situ tests and a unified relationship is appropriate only when β is less than 0.5. Thus, separate relationships between material constants are proposed for laboratory-based and in situ-based measurements. The results imply that the new models should be developed to apply in situ data.