SHEAR WAVE VELOCITY-BASED LIQUEFACTION RESISTANCE EVALUATION: SEMI-THEORETICAL CONSIDERATIONS AND EXPERIMENTAL VALIDATIONS

Shear wave velocity measurements provide a promising approach to liquefaction resistance evaluation of sandy soils. Although various relationships between shear wave velocity (Vs) and liquefaction resistance (CRR) have been developed, most of them are phenomenological rather than physically-based. In this study, semi-theoretical considerations are given and predict a soil-type specific relationship between CRR and Vs normalized with respect to the minimum void ratio, confining stress and exponent n of Hardin equation. Undrained cyclic triaxial test and dynamic centrifuge model test were performed on sands with Vs measured by bender elements to verify this relationship. Further investigation on similar laboratory studies resulted in a large database of sandy soils, which reveals that CRR is proportional to the 4 power of Vs at statistical level. Comparisons with field case histories show that the present lower-bound CRR-Vs curve is a reliable prediction of liquefaction resistance for most sandy soils, while the accurate evaluation for a specific site requires the development of site-specific liquefaction resistance curve.