The master thesis analyses swelling deformation that appeared in the deep motorway cut at Dragučova near Maribor. Soon after construction the deformation appeared as a pavement differential heave in the longitudinal and transversal direction. In the introduction the thesis presents geological investigation for the design and the history of the deep cut construction. It continues with the introduction of the methods for the recognition of swelling potential and with the theoretical background of a nonlinear analysis of vertical strain and the Soft soil model used by the programme PLAXIS. In the main part of the thesis the results, gathered with the experimental work and including index properties, swelling potential, swelling deformation and swelling pressure, are presented. These results were used for conventional computation of nonlinear vertical deformations and as input for the deep cut material model made in PLAXIS. The calculation results of vertical swelling deformations determined by using the two methods are in good agreement. Finally, the ratio of already mobilized heave and the time development of the expected deformation in the future are estimated.