Experimental and analytical investigation on the frictional contact behavior of 3D masonry block assemblages

• The frictional behavior of two stacked tuff blocks is experimentally investigated.
• Interactions among shear, torsion and bending moments are involved on the dry joint.
• Good agreement with existing numerical failure surfaces is observed.
• Original linearizations of 3D yield domains and their interactions are proposed.
• 3D rigid block limit analysis of a wall sample is presented for further validation.

Crucial to the limit analysis of 3D dry-jointed masonry block structures is a proper description of the constitutive laws that govern the frictional contact behavior. In this paper an extensive experimental investigation is carried out on a stack of two dry-jointed tuff blocks subjected to different loading conditions implying interactions among shear, torsion and bending moments. The results of each set are then compared with those obtained by the analytical model of two overlapped rigid blocks, under the assumptions of infinite compressive, shear and tensile strength for blocks and no-tension and frictional behavior at their contact. The non-linear yield functions are treated as piecewise linearizations in order to provide simplified expressions for mathematical programming in limit analysis formulations. Lastly, a simple example of 3D block assemblage with associative frictional contacts is analyzed using linear programming (LP) formulation to show the computational efficiency related to the developed yield functions.