Mechanical characterisation of lacustrine clay by interpreting spatial variability in CPTU measurements

Transportation infrastructure is common in highly populated areas near the major lakes in the Swiss 'Mittelland', where extensive deposits of normally consolidated post glacial clays have formed. Construction on, or in, such soils requires careful consideration during the design process due to their compressibility, low permeability and sensitivity. Achieving a satisfactory engineering characterisation requires a range of field and laboratory tests, which may be evaluated using statistical tools. The Intraclass ratio RI and the modified Bartlett method have been employed for interpreting the variability of the undrained shear strength su from continuous CPTU measurements at the Wauwil site. Finally, comparison between measurements from two cone dimensions, of cross sectional areas of 10 cm2 and 5 cm2, has been undertaken with respect to their capacity of profile detailing based on the normalised cone penetration resistance