Tubular columns, filled with concrete or not, are usually assumed encased to the foundation, although typical base plate connections are not always as rigid as supposed, due to the rotation of the plate and the deformation of the anchor bolts. Besides, the degradation of the rigidity after seismic loading leads to other alternatives like embedding the whole tube in the concrete base. The benefits of embedding the base vary depending basically on two parameters: the length of embedment and the filling or not of the tube. This study proposes a numerical analysis of this typology of connection, by focusing on the benefits of filling the tubes over the global stiffness. A set of different tubes of 100 and 200 mm of outer diameter, with different embedded lengths, have been analyzed monotonically and cyclically in order to see the influence of the core infill inside the tube on the rotational rigidity.