The Influence of Geometry on the Frictional Sliding of ∧ and ∨ Shaped Interlocking Joints in Masonry Assemblages

Applications of interlocking blocks improving the sliding resistance of masonry joints have recently been of significant interest to architects and structural engineers. In this framework, several works have studied the load capacity improvement of different joint shapes using various numerical and experimental analyses. However, applications of simplified and yet accurate analytical methods like limit analysis to interlocking blocks are rather unexplored and limited to a few interlocking joint shapes. To develop such a simplified analytical approach for interlocking assemblages with ∧ and ∨ shaped joints, this paper explores relationships between the shear capacities of flat and interlocking joints, allowing to abstract an assemblage of interlocking blocks to its equivalent assemblage with flat joints. This work specifically studies the interaction among friction, dilation, and inclination angles of the joints. To this aim, first the relationships between a flat and an interlocking joint of two stacked blocks are fully explored and then, the associative solution for an assemblage of two wedge blocks with flat faces is compared with the non-associative solution of the same assemblage with ∧ and ∨ shaped interlocking joints. Discrete element models using 3DEC are implemented to carry out the comparative analyses, in which the blocks are modelled as rigid units and the ultimate lateral load capacity of the assemblages is recorded.