ABSTRACT: This work studies the influence that the shape of the section of a column immersed in a watercourse has in relation to the hydrodynamic forces that arise due to fluid-structure interaction. The data about São Paulo state rivers’ flows and bridges were revised in order to determine a critical flow rate and choose the cross sections study cases. The simulations made with the ANSYS Fluent software allowed it to obtain the parameters of pressure and drag present in the surface of the column, and these values were used as a criterion to analyze the performance of different cross sections. The model was validated by comparison with the results from other authors in order to guarantee reliability to the study. The values obtained for different cross sections were compared to standardized values recommended by the Brazilian code NBR 7187/2003, when available.