This bachelor’s thesis deals with the design and assessment of a retaining structure for a cut-and-cover tunnel excavation in the Rousínov area under conditions of overconsolidated clays. The thesis focuses on the influence of geotechnical conditions and the choice of calculation approach on the design of the retaining structure and its behavior during construction. The anchored diaphragm wall was assessed using the GEO5 software, where the structure was analyzed in the ultimate limit state and from the perspective of deformations. A more detailed numerical analysis was subsequently carried out using the finite element method in the PLAXIS 2D program, which enabled evaluation of structural deformations, global stability, and ultimate limit state behavior. The influence of different constitutive soil models (Mohr–Coulomb, Hardening Soil, and Hardening Soil Small Strain) on the resulting internal forces and structural deformations was evaluated. The input parameters for the advanced HS and HSS models were determined through calibration based on laboratory CIUP triaxial tests using the SoilTestLab tool. An alternative solution using GFRP anchors was also considered. The results demonstrate the significant influence of the selected material model on the analysis results and confirm that advanced constitutive models accounting for small-strain stiffness are essential for realistic assessment of structures in overconsolidated clays.