This paper presents two numerical applications of a newly developed fully coupled thermo-hydro-mechanical-chemical finite-element code (Thebes code). The paper starts with an introduction of the adopted theoretical framework and its implementation, followed by a description of the performed simulations. The first application involves the modelling of a large-scale mock-up test performed by the Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (Madrid, Spain), which also serves as a validation benchmark. In the second application, the paper shows the solution to the Elder problem, which verifies the code’s capability to capture the density-driven salt transport triggered by hydro-chemical coupling. The results of both simulations are in good agreement with the published data and the experimental measurements, serving as a further validation of the theoretical assumptions and verification of the correctness of the code implementation.