The aim of the project is to investigate the indicator characteristics and the undrained shear strength of highly compressible cohesive soils, stabilized with fly ash and lime, which will act as an activator of pozzolanic reactions. The tests will be performed on five mixtures of cohesive soil with stabilizers in three test series. The ash content is expected to remain constant at 20%, while the lime content will vary from 0% to 20% every 5%. As a result, it will be possible to determine the amount of activator neccessary to create pozzolanic reactions. The project extends the MINIATURA 6 research project "Impact of fly ash addition on selected parameters of organic soils", obtained by the author. Research within the project will enrich knowledge of students of the GeKoN scientific club regarding research methods for an innovative type of strengthening of cohesive soil, i.e. stabilization with fly ashes and lime, and checking their effectiveness by comparing the results and trends with literature data for soils reinforced with traditional hydraulic binders (lime, cement, fly ash). The project results may allow for reducing the consumption of traditional binders, which will ultimately reduce the carbon footprint. Additionally, a new research equipment will become part of the laboratory of the Department of Goetechnical and Hydraulic Engineering. The project consists of two stages. The first stage concerns the study of indicator features. The program includes a comprehensive examination of the liquid limit and the plastic limit, the combination of which constitutes the indicator features: the degree of plasticity and the plasticity index. Yield point tests will be carried out according to ASTM D4318, and the liquid limit will be measured using the cone penetrometer method (tests according to BS 1377). The results regarding the liquid limit will be compared with literature data regarding organic and mineral soils without reinforcement and stabilized using traditional methods. The second part of the tests will consist of determining the maximum and residual shear strength in undrained conditions. The tests will be performed using a cone penetrometer and a pocket shear vane meter. The test results will be compiled and compared with more advanced tests - triaxial compression in conditions without drainage with initial anisotropic consolidation - the so-called CK0UC).