Probabilistic Modeling of Uncertainties in Sampling and Testing for Undrained Strength

Abstract

The reliability of geotechnical structures of short-term stability is largely affected by uncertainties contained in measured undrained strength of soils. The main sources of the uncertainties are (1) the inherent random variation of soil property in the in-situ ground, (2) stress release in boring, (3) mechanical disturbance during sampling and trimming of soil specimen, and (4) testing errors. These uncertainties are modeled in probabilistic manner and a new probabilistic model of measured undrained strength is proposed for normally consolidated and or lightly overconsolidated clay. The proposed model is attested by some actual data, and it is concluded that the proposed model can well predict the statistical parameters of in-situ undrained strength on the basis of those of the measured undrained strength.