The aim of the present work is to present a computational code in FORTRAN, based on the Finite Element Method, capable of simulating the thermal behavior of a two dimensional medium subjected to conduction heat transfer. The code is used to develop a numerical model of the buttress dam of the ITAIPU Hydroelectric Power Station (CHI). Thermo-structural coupling is performed using the temperature field as the nodal contour condition via the initial thermal deformation. In order to validate the model, the ANSYS® commercial software is used, the efficiency of which is proven in the technical literature, and the thermo-structural coupling of which is performed with the tools available in the Workbench. Finally, the results of the proposed coupling model are compared with the dam instrumentation data.