Kalibrering av CPTU för överkonsoliderad skånsk lera : Analys av konfaktorn

The clay in Scania is generally over consolidated. When the soil is evaluated by using CPTU, it is evaluated in the same way as it would be done for normal or slightly over consolidated clay. It has been shown that the undrained shear strength evaluated in this way is lower for the clay in Scania compared with what experience shows for this type of clay.A literature review was conducted to better understand how the shear strength is evaluated by using CPTU. Also which field methods and laboratory methods that is suitable for study the shear strength of the clay was studied. This study showed that CPTU was calibrated against direct simple shear test and a cone factor, NkT, is used too evaluated the undrained shear strength from CPTU.Two sample sites were selected, Ängelholm and Örtofta, where field tests were conducted and samples were collected. These sites were chosen from the knowledge that there would be over consolidated clay. Field tests and sampling was conducted in June and July 2015. Subsequent laboratory tests were carried out between August and October 2015 where the undrained shear strenght was determined. From the knowledge of the undrained shear strength of the clay from vane test, cone test, direct simple shear test and triaxial test, a new cone factor was calculated.The results indicate that a lower cone factor can be used for over consolidated clay. But it requires further laboratory tests to confirm and evaluate a representative cone factor.Validerat; 20160407 (global_studentproject_submitter