NON-LINEAR KINEMATIC ANALYSIS OF MASONRY WALLS OUT-OF-PLANE LOADED. THE COMPARATIVE ROLE OF FRICTION BETWEEN INTERLOCKED WALLS

In this paper the limit analysis of a simple out-of-plane failure mechanism of a laterally weakly connected masonry wall involving frictional resistances is developed according to the displacement-based approach. The pushover analysis is made considering geometric nonlinearity, i.e. by evaluating the static multiplier for varied kinematic configurations, as a function of the displacement of a control point. The effect of the interlocking between the front wall and the sidewalls gradually decreases after a certain displacement, due to the progressive detachment of the front wall and the variation of the frictional resistances can be represented by a non-linear function of the decreasing number of involved rows. The stabilizing role of friction between interlocked walls is compared to another system of strength in masonry buildings, i.e. the effect of tie-rods, with and without the detrimental effect of the static thrust of masonry vaults. The sensitivity of the load multiplier to these strength parameters is investigated with reference to different combinations of loading conditions. Comparative results and pushover curves are developed to evaluate the displacement capacities for each case analyzed.