The walls, if constructed with plain masonry would be incapable of resisting the magnitude of horizontal shear and bending forces imposed on them during earthquakes.
For this reason, in the modern reinforced masonry systems, reinforcing steel is incorporated to resist the shear and tensile stresses, so developed.
When these walls are subjected to lateral forces acting on them, they behave as flexural members spanning vertically between floors and horizontally between pilasters/ lateral walls.
Therefore reinforcement in both vertical and horizontal directions is required to be provided to develop resistance against torsion.
