The paper reports the main results obtained studying via numerical simulations two different solutions of cantilevered retaining structures in overconsolidated stiff clay. The behaviour of simply T shaped retaining structure is compared to the behaviour of a retaining structure made up of two diaphragm walls connected at the top by a rigid beam. This class of frameworks are used suitably for supporting deep excavations in order to minimize soil displacements in urban area, where the use of anchors is often not possible. Structural elements are assumed elastic and are simulated both by beam and continuum elements. A simple elastic perfect plastic constitutive model with Mohr-Coulomb strength criterion and zero dilatancy is adopted for describing the soil behaviour. The soil-structure interface is assumed purely frictional. The accuracy of the results presented is checked by a convergence study. The displacement and stress fields in structural elements under operating conditions for the two different solutions and for the different approaches adopted (beam or continuum) are reported and compared. Failure mechanisms are also investigated. The study provides a guidance to develop models to describe accurately the behaviour of this kind of structures.