Estimation of undrained shear strength in moderately OC clays based on field vane test data

Abstract

The undrained shear strength (s u) of cohesive soils is a crucial parameter for many geotechnical engineering applications. Due to the complexities and uncertainties associated with laboratory and in situ tests, it is a challenging task to obtain the undrained shear strength in a reliable and economical manner. In this study, a probabilistic model for the s u of moderately overconsolidated clays is developed using the Bayesian model class selection approach. The model is based on a comprehensive geotechnical database compiled for this study with field measurements of field vane strength (s u), plastic limit (PL), natural water content (W n), liquid limit (LL), vertical effective overburden stress ( $$\sigma_{\nu }^{\prime }$$ ), preconsolidation pressure ( $$\sigma_{\text{p}}^{\prime }$$ ) and overconsolidated ratio (OCR). Comparison study shows that the proposed model is superior to some well-known empirical relationships for OC clays. The proposed probabilistic model not only provides reliable and economical estimation of s u but also facilitates reliability-based analysis and design for performance-based engineering applications.