Evaluation of geotechnical property variability

To evaluate geotechnical variability on a general basis that will facilitat e the use of reliability-based design procedures, it is necessary to assess inherent soil variability, measurement error, and transformation uncertain ty separately. The inherent variability and measurement error are addressed in a companion paper, and transformation uncertainty is addressed herein. A second-moment probabilistic approach is applied to combine these uncertai nties consistently based on the manner in which the design soil property is derived. The design properties considered in this paper are undrained shea r strength, effective stress friction angle, in situ horizontal stress coef ficient, and Young's modulus. This paper concludes with specific guidelines on the typical coefficients of variation for these common design soil prop erties as a function of the test type and the type of correlation used.