1 What limitations might there be in using Bjerrums correcti

1. What limitations might there be in using Bjerrum\'s correction factor? Hint: look at the plot. 2. Why might values of a vane shear test fall outside the bounds of those provided by Ladd et al., 1977?

Solution

ANSWER 1- The correction factor was based on results from tests in clays with an OCR (overconsolidation ratio) of approximately 1.3, the method of correction is therefore applicable for normally and lightly overconsolidated clays. Clays with OCR1.5 are defined as overconsolidated  and correction factor was not applicable for overconsolidated clay.

ANSWER 2- VANE Shear test  without casing causes friction on the rod which gives a higher torque. hence some values of tests falls outside the bounds.