ABSTRACT
The multi-storey wall with openings and large architraves, generally reinforced at floor levels by steel ties, is the more relevant resistant structural component of the masonry building under seismic action. Steel strengths of the ties have thus to be suitably chosen in order to avoid the local failures and ensure the development of the global failure of the wall. The in-plane failure of the regular multi-storey walls can occur developing various mechanisms in dependence of the geometry of the walls and of the strengths of the horizontal reinforcements. The collapse multiplier is obtained by applying the Kinematic Theorem of the Limit Analysis, which equalizes the resistant and pushing works along the mechanism. In order to perform the static check, it is necessary to evaluate the actions Rij between the piers and the architraves: as the problem is statically determined, being known the axial forces of the steel ties, they can be evaluated through the equilibrium conditions.
