For every structure, frame stability is an important area of consideration. Designers of structural steel-work were the first to recognize the importance of considering the stability of steel frames in BS-5950.
The principle of virtual work sometimes known as the “unit-load” method was developed by John Bernoulli in 1717. It is a direct application of the principle of conservation of energy
Thus, one of the methods of ensuring lateral stability and avoiding excessive lateral deflection is by deploying shear walls across the width of the building to resist the lateral forces.
Flat slabs are reinforced concrete slabs supported directly on columns, without beams. They are sometimes thickened at the columns to form column drops.