© 2019 Taylor & Francis Group, London.The basic purpose of this study is to analyze the possibility of using vane shear testing device for optimizing soil conditioning. The soil sample was obtained during excavation of SK-15 shaft of the Ayvali 2 Wastewater Tunnel in Istanbul. The natural water content, specific gravity, size distribution and consistency limits of the soil sample were determined. An anticlay foaming agent was used in the tests. Mixing, cone penetrometer, flow table and vane shear (pocket type) tests were performed on the mixture of soil and foaming agent at certain water content. CF of 3% and FER of 16 were kept constant and FIR was varied. The experimental results were validated by field performance measurements. The laboratory and field studies indicated that optimum conditioning parameters and consistency of conditioned soils could be determined by vane shear testing. There were strong relationships between the results of classical testing methods and vane shear device.