MACRO AND MICRO-BLOCK MODELING APPROACHES FOR THE OUT-OF-PLANE LOAD CAPACITY OF A MASONRY WALL WITH TWO SIDEWALLS

In this paper, novel macro and micro-block modeling approaches are adopted for the assessment of the collapse load factor and failure mode of block masonry structures. The out-of-plane behavior of a masonry system composed of a façade wall connected with two sidewalls is investigated by means of limit analysis and some recurrent classes of mechanisms are analyzed. These involve rocking, sliding, torsion failure and combinations of them. Both modeling approaches consider masonry as an assemblage of dry rigid blocks with frictional behavior and non-associative flow rules. The macro-block modeling is based on the assumption that all the possible relative motions among micro-blocks are concentrated along the cracks; assuming maximum and minimum frictional resistances along the cracks, two limiting conditions for the ultimate load factor are kinematically computed by use of minimization routines. The micro-block model is based on a novel numerical strategy to solve the non-associative friction problem; second order cone programming (SOCP) is used to allow the conic yield function to be solved directly. Proper graphics show the obtained results with reference to some given geometric parameters and comparisons between both approaches.